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2 | +1. Methods Mol Biol. 2018;1737:77-88. doi: 10.1007/978-1-4939-7634-8_5. | ||
3 | + | ||
4 | +Identification of New Bacterial Small RNA Targets Using MS2 Affinity Purification | ||
5 | +Coupled to RNA Sequencing. | ||
6 | + | ||
7 | +Carrier MC(1), Laliberté G(1), Massé E(2). | ||
8 | + | ||
9 | +Author information: | ||
10 | +(1)Department of Biochemistry, RNA Group, Université de Sherbrooke, Sherbrooke, | ||
11 | +QC, Canada. | ||
12 | +(2)Department of Biochemistry, RNA Group, Université de Sherbrooke, Sherbrooke, | ||
13 | +QC, Canada. eric.masse@usherbrooke.ca. | ||
14 | + | ||
15 | +Small regulatory RNAs (sRNAs) are ubiquitous regulatory molecules expressed in | ||
16 | +living cells. In prokaryotes, sRNAs usually bind to target mRNAs to either | ||
17 | +promote their degradation or interfere with translation initiation. Because a | ||
18 | +single sRNA can regulate a considerable number of target mRNAs, we seek to | ||
19 | +identify those targets rapidly and reliably. Here, we present a robust method | ||
20 | +based on the co-purification of target mRNAs bound to MS2-tagged sRNAs expressed | ||
21 | +in vivo. After purification of the tagged-sRNA, we use RNAseq to determine the | ||
22 | +identity of all RNA interacting partners and their enrichment level. We describe | ||
23 | +how to analyze the RNAseq data through the Galaxy Project Platform bioinformatics | ||
24 | +tools to identify new mRNA targets. This technique is applicable to most sRNAs of | ||
25 | +E. coli and Salmonella. | ||
26 | + | ||
27 | +DOI: 10.1007/978-1-4939-7634-8_5 | ||
28 | +PMID: 29484588 | ||
29 | + | ||
30 | + | ||
31 | +2. BMC Evol Biol. 2018 Feb 12;18(1):21. doi: 10.1186/s12862-018-1134-0. | ||
32 | + | ||
33 | +A novel short L-arginine responsive protein-coding gene (laoB) antiparallel | ||
34 | +overlapping to a CadC-like transcriptional regulator in Escherichia coli O157:H7 | ||
35 | +Sakai originated by overprinting. | ||
36 | + | ||
37 | +Hücker SM(1)(2), Vanderhaeghen S(1), Abellan-Schneyder I(1)(3), Wecko R(1), Simon | ||
38 | +S(4), Scherer S(1)(5), Neuhaus K(6)(7). | ||
39 | + | ||
40 | +Author information: | ||
41 | +(1)Chair for Microbial Ecology, Wissenschaftszentrum Weihenstephan, Technische | ||
42 | +Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
43 | +(2)Fraunhofer ITEM-R, Am Biopark 9, 93053, Regensburg, Germany. | ||
44 | +(3)Core Facility Microbiome/NGS, ZIEL - Institute for Food & Health, Technische | ||
45 | +Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
46 | +(4)Department of Computer and Information Science, University of Konstanz, Box | ||
47 | +78, 78457, Konstanz, Germany. | ||
48 | +(5)ZIEL - Institute for Food & Health, Technische Universität München, | ||
49 | +Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
50 | +(6)Chair for Microbial Ecology, Wissenschaftszentrum Weihenstephan, Technische | ||
51 | +Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
52 | +neuhaus@tum.de. | ||
53 | +(7)Core Facility Microbiome/NGS, ZIEL - Institute for Food & Health, Technische | ||
54 | +Universität München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
55 | +neuhaus@tum.de. | ||
56 | + | ||
57 | +BACKGROUND: Due to the DNA triplet code, it is possible that the sequences of two | ||
58 | +or more protein-coding genes overlap to a large degree. However, such non-trivial | ||
59 | +overlaps are usually excluded by genome annotation pipelines and, thus, only a | ||
60 | +few overlapping gene pairs have been described in bacteria. In contrast, | ||
61 | +transcriptome and translatome sequencing reveals many signals originated from the | ||
62 | +antisense strand of annotated genes, of which we analyzed an example gene pair in | ||
63 | +more detail. | ||
64 | +RESULTS: A small open reading frame of Escherichia coli O157:H7 strain Sakai | ||
65 | +(EHEC), designated laoB (L-arginine responsive overlapping gene), is embedded in | ||
66 | +reading frame -2 in the antisense strand of ECs5115, encoding a CadC-like | ||
67 | +transcriptional regulator. This overlapping gene shows evidence of transcription | ||
68 | +and translation in Luria-Bertani (LB) and brain-heart infusion (BHI) medium based | ||
69 | +on RNA sequencing (RNAseq) and ribosomal-footprint sequencing (RIBOseq). The | ||
70 | +transcriptional start site is 289 base pairs (bp) upstream of the start codon and | ||
71 | +transcription termination is 155 bp downstream of the stop codon. Overexpression | ||
72 | +of LaoB fused to an enhanced green fluorescent protein (EGFP) reporter was | ||
73 | +possible. The sequence upstream of the transcriptional start site displayed | ||
74 | +strong promoter activity under different conditions, whereas promoter activity | ||
75 | +was significantly decreased in the presence of L-arginine. A strand-specific | ||
76 | +translationally arrested mutant of laoB provided a significant growth advantage | ||
77 | +in competitive growth experiments in the presence of L-arginine compared to the | ||
78 | +wild type, which returned to wild type level after complementation of laoB in | ||
79 | +trans. A phylostratigraphic analysis indicated that the novel gene is restricted | ||
80 | +to the Escherichia/Shigella clade and might have originated recently by | ||
81 | +overprinting leading to the expression of part of the antisense strand of | ||
82 | +ECs5115. | ||
83 | +CONCLUSIONS: Here, we present evidence of a novel small protein-coding gene laoB | ||
84 | +encoded in the antisense frame -2 of the annotated gene ECs5115. Clearly, laoB is | ||
85 | +evolutionarily young and it originated in the Escherichia/Shigella clade by | ||
86 | +overprinting, a process which may cause the de novo evolution of bacterial genes | ||
87 | +like laoB. | ||
88 | + | ||
89 | +DOI: 10.1186/s12862-018-1134-0 | ||
90 | +PMCID: PMC5810103 | ||
91 | +PMID: 29433444 | ||
92 | + | ||
93 | + | ||
94 | +3. PLoS One. 2017 Sep 13;12(9):e0184119. doi: 10.1371/journal.pone.0184119. | ||
95 | +eCollection 2017. | ||
96 | + | ||
97 | +Discovery of numerous novel small genes in the intergenic regions of the | ||
98 | +Escherichia coli O157:H7 Sakai genome. | ||
99 | + | ||
100 | +Hücker SM(1)(2), Ardern Z(1)(2), Goldberg T(3), Schafferhans A(3), Bernhofer | ||
101 | +M(3), Vestergaard G(4), Nelson CW(5), Schloter M(4), Rost B(3), Scherer S(1)(2), | ||
102 | +Neuhaus K(1)(6). | ||
103 | + | ||
104 | +Author information: | ||
105 | +(1)Chair for Microbial Ecology, Technische Universität München, Freising, | ||
106 | +Germany. | ||
107 | +(2)ZIEL - Institute for Food & Health, Technische Universität München, Freising, | ||
108 | +Germany. | ||
109 | +(3)Department of Informatics-Bioinformatics & TUM-IAS, Technische Universität | ||
110 | +München, Garching, Germany. | ||
111 | +(4)Research Unit Environmental Genomics, Helmholtz Zentrum München, Neuherberg, | ||
112 | +Germany. | ||
113 | +(5)Sackler Institute for Comparative Genomics, American Museum of Natural History | ||
114 | +New York, New York, United States of America. | ||
115 | +(6)Core Facility Microbiome/NGS, ZIEL - Institute for Food & Health, Technische | ||
116 | +Universität München, Freising, Germany. | ||
117 | + | ||
118 | +In the past, short protein-coding genes were often disregarded by genome | ||
119 | +annotation pipelines. Transcriptome sequencing (RNAseq) signals outside of | ||
120 | +annotated genes have usually been interpreted to indicate either ncRNA or | ||
121 | +pervasive transcription. Therefore, in addition to the transcriptome, the | ||
122 | +translatome (RIBOseq) of the enteric pathogen Escherichia coli O157:H7 strain | ||
123 | +Sakai was determined at two optimal growth conditions and a severe stress | ||
124 | +condition combining low temperature and high osmotic pressure. All intergenic | ||
125 | +open reading frames potentially encoding a protein of ≥ 30 amino acids were | ||
126 | +investigated with regard to coverage by transcription and translation signals and | ||
127 | +their translatability expressed by the ribosomal coverage value. This led to | ||
128 | +discovery of 465 unique, putative novel genes not yet annotated in this E. coli | ||
129 | +strain, which are evenly distributed over both DNA strands of the genome. For 255 | ||
130 | +of the novel genes, annotated homologs in other bacteria were found, and a | ||
131 | +machine-learning algorithm, trained on small protein-coding E. coli genes, | ||
132 | +predicted that 89% of these translated open reading frames represent bona fide | ||
133 | +genes. The remaining 210 putative novel genes without annotated homologs were | ||
134 | +compared to the 255 novel genes with homologs and to 250 short annotated genes of | ||
135 | +this E. coli strain. All three groups turned out to be similar with respect to | ||
136 | +their translatability distribution, fractions of differentially regulated genes, | ||
137 | +secondary structure composition, and the distribution of evolutionary constraint, | ||
138 | +suggesting that both novel groups represent legitimate genes. However, the | ||
139 | +machine-learning algorithm only recognized a small fraction of the 210 genes | ||
140 | +without annotated homologs. It is possible that these genes represent a novel | ||
141 | +group of genes, which have unusual features dissimilar to the genes of the | ||
142 | +machine-learning algorithm training set. | ||
143 | + | ||
144 | +DOI: 10.1371/journal.pone.0184119 | ||
145 | +PMCID: PMC5597208 | ||
146 | +PMID: 28902868 [Indexed for MEDLINE] | ||
147 | + | ||
148 | + | ||
149 | +4. Int J Genomics. 2017;2017:6489383. doi: 10.1155/2017/6489383. Epub 2017 Jul 16. | ||
150 | + | ||
151 | +Differential MicroRNA Analyses of Burkholderia pseudomallei- and Francisella | ||
152 | +tularensis-Exposed hPBMCs Reveal Potential Biomarkers. | ||
153 | + | ||
154 | +Cer RZ(1)(2), Herrera-Galeano JE(1)(2)(3), Frey KG(1)(2), Schully KL(1)(2), Luu | ||
155 | +TV(1)(2), Pesce J(1)(2)(4), Mokashi VP(1)(5), Keane-Myers AM(1)(2)(6), | ||
156 | +Bishop-Lilly KA(1)(2). | ||
157 | + | ||
158 | +Author information: | ||
159 | +(1)Genomics and Bioinformatics Department, Biological Defense Research | ||
160 | +Directorate, Naval Medical Research Center, Frederick, MD, USA. | ||
161 | +(2)Henry M. Jackson Foundation for the Advancement of Military Medicine, | ||
162 | +Bethesda, MD, USA. | ||
163 | +(3)KCE Services and Consulting LLC, Columbia, MD, USA. | ||
164 | +(4)Division of Microbiology and Infectious Diseases, National Institute of | ||
165 | +Allergy and Infectious Diseases, Bethesda, MD, USA. | ||
166 | +(5)Navy Drug Screening Laboratory, Jacksonville, FL, USA. | ||
167 | +(6)Immunology, National Institute of Health, Bethesda, MD, USA. | ||
168 | + | ||
169 | +Increasing evidence that microRNAs (miRNAs) play important roles in the immune | ||
170 | +response against infectious agents suggests that miRNA might be exploitable as | ||
171 | +signatures of exposure to specific infectious agents. In order to identify | ||
172 | +potential early miRNA biomarkers of bacterial infections, human peripheral blood | ||
173 | +mononuclear cells (hPBMCs) were exposed to two select agents, Burkholderia | ||
174 | +pseudomallei K96243 and Francisella tularensis SHU S4, as well as to the | ||
175 | +nonpathogenic control Escherichia coli DH5α. RNA samples were harvested at three | ||
176 | +early time points, 30, 60, and 120 minutes postexposure, then sequenced. RNAseq | ||
177 | +analyses identified 87 miRNAs to be differentially expressed (DE) in a linear | ||
178 | +fashion. Of these, 31 miRNAs were tested using the miScript miRNA qPCR assay. | ||
179 | +Through RNAseq identification and qPCR validation, we identified differentially | ||
180 | +expressed miRNA species that may be involved in the early response to bacterial | ||
181 | +infections. Based upon its upregulation at early time points postexposure in two | ||
182 | +different individuals, hsa-mir-30c-5p is a miRNA species that could be studied | ||
183 | +further as a potential biomarker for exposure to these gram-negative | ||
184 | +intracellular pathogens. Gene ontology functional analyses demonstrated that | ||
185 | +programmed cell death is the first ranking biological process associated with | ||
186 | +miRNAs that are upregulated in F. tularensis-exposed hPBMCs. | ||
187 | + | ||
188 | +DOI: 10.1155/2017/6489383 | ||
189 | +PMCID: PMC5534298 | ||
190 | +PMID: 28791299 | ||
191 | + | ||
192 | + | ||
193 | +5. PLoS One. 2017 Jun 14;12(6):e0178966. doi: 10.1371/journal.pone.0178966. | ||
194 | +eCollection 2017. | ||
195 | + | ||
196 | +Intestinal organoids model human responses to infection by commensal and Shiga | ||
197 | +toxin producing Escherichia coli. | ||
198 | + | ||
199 | +Karve SS(1), Pradhan S(1), Ward DV(2), Weiss AA(1). | ||
200 | + | ||
201 | +Author information: | ||
202 | +(1)Department of Molecular Genetics, Biochemistry, and Microbiology, University | ||
203 | +of Cincinnati, Cincinnati, Ohio, United States of America. | ||
204 | +(2)Center for Microbiome Research and Department of Microbiology and | ||
205 | +Physiological Systems, University of Massachusetts Medical School, Worcester, | ||
206 | +Massachusetts, United States of America. | ||
207 | + | ||
208 | +Infection with Shiga toxin (Stx) producing Escherichia coli O157:H7 can cause the | ||
209 | +potentially fatal complication hemolytic uremic syndrome, and currently only | ||
210 | +supportive therapy is available. Lack of suitable animal models has hindered | ||
211 | +study of this disease. Induced human intestinal organoids (iHIOs), generated by | ||
212 | +in vitro differentiation of pluripotent stem cells, represent differentiated | ||
213 | +human intestinal tissue. We show that iHIOs with addition of human neutrophils | ||
214 | +can model E. coli intestinal infection and innate cellular responses. Commensal | ||
215 | +and O157:H7 introduced into the iHIO lumen replicated rapidly achieving high | ||
216 | +numbers. Commensal E. coli did not cause damage, and were completely contained | ||
217 | +within the lumen, suggesting defenses, such as mucus production, can constrain | ||
218 | +non-pathogenic strains. Some O157:H7 initially co-localized with cellular actin. | ||
219 | +Loss of actin and epithelial integrity was observed after 4 hours. O157:H7 grew | ||
220 | +as filaments, consistent with activation of the bacterial SOS stress response. | ||
221 | +SOS is induced by reactive oxygen species (ROS), and O157:H7 infection increased | ||
222 | +ROS production. Transcriptional profiling (RNAseq) demonstrated that both | ||
223 | +commensal and O157:H7 upregulated genes associated with gastrointestinal | ||
224 | +maturation, while infection with O157:H7 upregulated inflammatory responses, | ||
225 | +including interleukin 8 (IL-8). IL-8 is associated with neutrophil recruitment, | ||
226 | +and infection with O157:H7 resulted in recruitment of human neutrophils into the | ||
227 | +iHIO tissue. | ||
228 | + | ||
229 | +DOI: 10.1371/journal.pone.0178966 | ||
230 | +PMCID: PMC5470682 | ||
231 | +PMID: 28614372 [Indexed for MEDLINE] | ||
232 | + | ||
233 | + | ||
234 | +6. BMC Genet. 2017 Mar 7;18(1):21. doi: 10.1186/s12863-017-0488-4. | ||
235 | + | ||
236 | +Deciphering alternative splicing and nonsense-mediated decay modulate expression | ||
237 | +in primary lymphoid tissues of birds infected with avian pathogenic E. coli | ||
238 | +(APEC). | ||
239 | + | ||
240 | +Sun H(1). | ||
241 | + | ||
242 | +Author information: | ||
243 | +(1)College of Animal Science and Technology, Yangzhou University, Yangzhou, | ||
244 | +Jiangsu, 225009, China. hongyans2392@163.com. | ||
245 | + | ||
246 | +BACKGROUND: Avian pathogenic E. coli (APEC) can lead to a loss in millions of | ||
247 | +dollars in poultry annually because of mortality and produce contamination. | ||
248 | +Studies have verified that many immune-related genes undergo changes in | ||
249 | +alternative splicing (AS), along with nonsense mediated decay (NMD), to regulate | ||
250 | +the immune system under different conditions. Therefore, the splicing profiles of | ||
251 | +primary lymphoid tissues with systemic APEC infection need to be comprehensively | ||
252 | +examined. | ||
253 | +RESULTS: Gene expression in RNAseq data were obtained for three different immune | ||
254 | +tissues (bone marrow, thymus, and bursa) from three phenotype birds | ||
255 | +(non-challenged, resistant, and susceptible birds) at two time points. | ||
256 | +Alternative 5' splice sites and exon skipping/inclusion were identified as the | ||
257 | +major alternative splicing events in avian primary immune organs under systemic | ||
258 | +APEC infection. In this study, we detected hundreds of | ||
259 | +differentially-expressed-transcript-containing genes (DETs) between different | ||
260 | +phenotype birds at 5 days post-infection (dpi). DETs, PSAP and STT3A, with NMD | ||
261 | +have important functions under systemic APEC infection. DETs, CDC45, CDK1, RAG2, | ||
262 | +POLR1B, PSAP, and DNASE1L3, from the same transcription start sites (TSS) | ||
263 | +indicate that cell death, cell cycle, cellular function, and maintenance were | ||
264 | +predominant in host under systemic APEC. | ||
265 | +CONCLUSIONS: With the use of RNAseq technology and bioinformatics tools, this | ||
266 | +study provides a portrait of the AS event and NMD in primary lymphoid tissues, | ||
267 | +which play critical roles in host homeostasis under systemic APEC infection. | ||
268 | +According to this study, AS plays a pivotal regulatory role in the immune | ||
269 | +response in chicken under systemic APEC infection via either NMD or alternative | ||
270 | +TSSs. This study elucidates the regulatory role of AS for the immune complex | ||
271 | +under systemic APEC infection. | ||
272 | + | ||
273 | +DOI: 10.1186/s12863-017-0488-4 | ||
274 | +PMCID: PMC5341183 | ||
275 | +PMID: 28270101 [Indexed for MEDLINE] | ||
276 | + | ||
277 | + | ||
278 | +7. BMC Genomics. 2017 Feb 28;18(1):216. doi: 10.1186/s12864-017-3586-9. | ||
279 | + | ||
280 | +Differentiation of ncRNAs from small mRNAs in Escherichia coli O157:H7 EDL933 | ||
281 | +(EHEC) by combined RNAseq and RIBOseq - ryhB encodes the regulatory RNA RyhB and | ||
282 | +a peptide, RyhP. | ||
283 | + | ||
284 | +Neuhaus K(1)(2), Landstorfer R(3), Simon S(4), Schober S(5), Wright PR(6), Smith | ||
285 | +C(6), Backofen R(6), Wecko R(3), Keim DA(4), Scherer S(3). | ||
286 | + | ||
287 | +Author information: | ||
288 | +(1)Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, | ||
289 | +Technische Universität München, Weihenstephaner Berg 3, D-85354, Freising, | ||
290 | +Germany. neuhaus@tum.de. | ||
291 | +(2)Core Facility Microbiome/NGS, ZIEL Institute for Food & Health, | ||
292 | +Weihenstephaner Berg 3, D-85354, Freising, Germany. neuhaus@tum.de. | ||
293 | +(3)Lehrstuhl für Mikrobielle Ökologie, Wissenschaftszentrum Weihenstephan, | ||
294 | +Technische Universität München, Weihenstephaner Berg 3, D-85354, Freising, | ||
295 | +Germany. | ||
296 | +(4)Informatik und Informationswissenschaft, Universität Konstanz, D-78457, | ||
297 | +Konstanz, Germany. | ||
298 | +(5)Institut für Nachrichtentechnik, Universität Ulm, Albert-Einstein-Allee 43, | ||
299 | +D-89081, Ulm, Germany. | ||
300 | +(6)Bioinformatics Group, Department of Computer Science and BIOSS Centre for | ||
301 | +Biological Signaling Studies, Cluster of Excellence, University of Freiburg, | ||
302 | +D-79110, Freiburg, Germany. | ||
303 | + | ||
304 | +BACKGROUND: While NGS allows rapid global detection of transcripts, it remains | ||
305 | +difficult to distinguish ncRNAs from short mRNAs. To detect potentially | ||
306 | +translated RNAs, we developed an improved protocol for bacterial ribosomal | ||
307 | +footprinting (RIBOseq). This allowed distinguishing ncRNA from mRNA in EHEC. A | ||
308 | +high ratio of ribosomal footprints per transcript (ribosomal coverage value, RCV) | ||
309 | +is expected to indicate a translated RNA, while a low RCV should point to a | ||
310 | +non-translated RNA. | ||
311 | +RESULTS: Based on their low RCV, 150 novel non-translated EHEC transcripts were | ||
312 | +identified as putative ncRNAs, representing both antisense and intergenic | ||
313 | +transcripts, 74 of which had expressed homologs in E. coli MG1655. Bioinformatics | ||
314 | +analysis predicted statistically significant target regulons for 15 of the | ||
315 | +intergenic transcripts; experimental analysis revealed 4-fold or higher | ||
316 | +differential expression of 46 novel ncRNA in different growth media. Out of 329 | ||
317 | +annotated EHEC ncRNAs, 52 showed an RCV similar to protein-coding genes, of | ||
318 | +those, 16 had RIBOseq patterns matching annotated genes in other | ||
319 | +enterobacteriaceae, and 11 seem to possess a Shine-Dalgarno sequence, suggesting | ||
320 | +that such ncRNAs may encode small proteins instead of being solely non-coding. To | ||
321 | +support that the RIBOseq signals are reflecting translation, we tested the | ||
322 | +ribosomal-footprint covered ORF of ryhB and found a phenotype for the encoded | ||
323 | +peptide in iron-limiting condition. | ||
324 | +CONCLUSION: Determination of the RCV is a useful approach for a rapid first-step | ||
325 | +differentiation between bacterial ncRNAs and small mRNAs. Further, many known | ||
326 | +ncRNAs may encode proteins as well. | ||
327 | + | ||
328 | +DOI: 10.1186/s12864-017-3586-9 | ||
329 | +PMCID: PMC5331693 | ||
330 | +PMID: 28245801 [Indexed for MEDLINE] | ||
331 | + | ||
332 | + | ||
333 | +8. ACS Appl Mater Interfaces. 2017 Mar 22;9(11):10047-10060. doi: | ||
334 | +10.1021/acsami.7b02380. Epub 2017 Mar 10. | ||
335 | + | ||
336 | +Transcriptome Analysis Reveals Silver Nanoparticle-Decorated Quercetin | ||
337 | +Antibacterial Molecular Mechanism. | ||
338 | + | ||
339 | +Sun D(1), Zhang W(1), Mou Z(1), Chen Y(1), Guo F(1), Yang E(1), Wang W(1). | ||
340 | + | ||
341 | +Author information: | ||
342 | +(1)School of Life Sciences, Anhui Agricultural University , Hefei 230036, China. | ||
343 | + | ||
344 | +Facile and simple method is developed to synthesize silver-nanoparticle-decorated | ||
345 | +quercetin nanoparticles (QA NPs). Modification suggests that synergistic | ||
346 | +quercetin (Qe) improves the antibacterial effect of silver nanoparticles (Ag | ||
347 | +NPs). Characterization experiment indicates that QA NPs have a diameter of | ||
348 | +approximately 10 nm. QA NPs show highly effective antibacterial activities | ||
349 | +against drug-resistant Escherichia coli (E. coli) and Staphylococcus aureus (S. | ||
350 | +aureus). We explore antibacterial mechanisms using S. aureus and E. coli treated | ||
351 | +with QA NPs. Through morphological changes in E. coli and S. aureus, mechanisms | ||
352 | +are examined for bacterial damage caused by particulate matter from local | ||
353 | +dissociation of silver ion and Qe from QA NPs trapped inside membranes. Moreover, | ||
354 | +we note that gene expression profiling methods, such as RNA sequencing, can be | ||
355 | +used to predict discover mechanisms of toxicity of QA NPs. Gene ontology (GO) | ||
356 | +assay analyses demonstrate the molecular mechanism of the antibacterial effect of | ||
357 | +QA NPs. Regarding cellular component ontology, "cell wall organization or | ||
358 | +biogenesis" (GO: 0071554) and "cell wall macromolecule metabolic process" (GO: | ||
359 | +0044036) are the most represented categories. The present study reports that | ||
360 | +transcriptome analysis of the mechanism offers novel insights into the molecular | ||
361 | +mechanism of antibacterial assays. | ||
362 | + | ||
363 | +DOI: 10.1021/acsami.7b02380 | ||
364 | +PMID: 28240544 | ||
365 | + | ||
366 | + | ||
367 | +9. Biotechnol Biofuels. 2017 Feb 3;10:32. doi: 10.1186/s13068-017-0720-5. | ||
368 | +eCollection 2017. | ||
369 | + | ||
370 | +Development of a genetically programed vanillin-sensing bacterium for | ||
371 | +high-throughput screening of lignin-degrading enzyme libraries. | ||
372 | + | ||
373 | +Sana B(1), Chia KHB(2), Raghavan SS(1), Ramalingam B(3), Nagarajan N(2), Seayad | ||
374 | +J(3), Ghadessy FJ(1). | ||
375 | + | ||
376 | +Author information: | ||
377 | +(1)p53 Laboratory, Agency for Science Technology And Research (ASTAR), 8A | ||
378 | +Biomedical Grove, #06-04/05 Neuros/Immunos, Singapore, 138648 Singapore. | ||
379 | +(2)Genome Institute of Singapore, 60 Biopolis Street, Genome, #02-01, Singapore, | ||
380 | +138672 Singapore. | ||
381 | +(3)Institute of Chemical and Engineering Sciences, 8 Biomedical Grove, Neuros, | ||
382 | +#07-01, Singapore, 138665 Singapore. | ||
383 | + | ||
384 | +BACKGROUND: Lignin is a potential biorefinery feedstock for the production of | ||
385 | +value-added chemicals including vanillin. A huge amount of lignin is produced as | ||
386 | +a by-product of the paper industry, while cellulosic components of plant biomass | ||
387 | +are utilized for the production of paper pulp. In spite of vast potential, lignin | ||
388 | +remains the least exploited component of plant biomass due to its extremely | ||
389 | +complex and heterogenous structure. Several enzymes have been reported to have | ||
390 | +lignin-degrading properties and could be potentially used in lignin biorefining | ||
391 | +if their catalytic properties could be improved by enzyme engineering. The much | ||
392 | +needed improvement of lignin-degrading enzymes by high-throughput selection | ||
393 | +techniques such as directed evolution is currently limited, as robust methods for | ||
394 | +detecting the conversion of lignin to desired small molecules are not available. | ||
395 | +RESULTS: We identified a vanillin-inducible promoter by RNAseq analysis of | ||
396 | +Escherichia coli cells treated with a sublethal dose of vanillin and developed a | ||
397 | +genetically programmed vanillin-sensing cell by placing the 'very green | ||
398 | +fluorescent protein' gene under the control of this promoter. Fluorescence of the | ||
399 | +biosensing cell is enhanced significantly when grown in the presence of vanillin | ||
400 | +and is readily visualized by fluorescence microscopy. The use of | ||
401 | +fluorescence-activated cell sorting analysis further enhances the sensitivity, | ||
402 | +enabling dose-dependent detection of as low as 200 µM vanillin. The biosensor is | ||
403 | +highly specific to vanillin and no major response is elicited by the presence of | ||
404 | +lignin, lignin model compound, DMSO, vanillin analogues or non-specific toxic | ||
405 | +chemicals. | ||
406 | +CONCLUSIONS: We developed an engineered E. coli cell that can detect vanillin at | ||
407 | +a concentration as low as 200 µM. The vanillin-sensing cell did not show | ||
408 | +cross-reactivity towards lignin or major lignin degradation products including | ||
409 | +vanillin analogues. This engineered E. coli cell could potentially be used as a | ||
410 | +host cell for screening lignin-degrading enzymes that can convert lignin to | ||
411 | +vanillin. | ||
412 | + | ||
413 | +DOI: 10.1186/s13068-017-0720-5 | ||
414 | +PMCID: PMC5291986 | ||
415 | +PMID: 28174601 | ||
416 | + | ||
417 | + | ||
418 | +10. PLoS Negl Trop Dis. 2017 Jan 6;11(1):e0005273. doi: 10.1371/journal.pntd.0005273. | ||
419 | +eCollection 2017 Jan. | ||
420 | + | ||
421 | +Transcriptome Sequencing Reveals Large-Scale Changes in Axenic Aedes aegypti | ||
422 | +Larvae. | ||
423 | + | ||
424 | +Vogel KJ(1), Valzania L(1), Coon KL(1), Brown MR(1), Strand MR(1). | ||
425 | + | ||
426 | +Author information: | ||
427 | +(1)Department of Entomology, The University of Georgia, Athens, Georgia, United | ||
428 | +States of America. | ||
429 | + | ||
430 | +Mosquitoes host communities of microbes in their digestive tract that consist | ||
431 | +primarily of bacteria. We previously reported that Aedes aegypti larvae colonized | ||
432 | +by a native community of bacteria and gnotobiotic larvae colonized by only | ||
433 | +Escherichia coli develop very similarly into adults, whereas axenic larvae never | ||
434 | +molt and die as first instars. In this study, we extended these findings by first | ||
435 | +comparing the growth and abundance of bacteria in conventional, gnotobiotic, and | ||
436 | +axenic larvae during the first instar. Results showed that conventional and | ||
437 | +gnotobiotic larvae exhibited no differences in growth, timing of molting, or | ||
438 | +number of bacteria in their digestive tract. Axenic larvae in contrast grew | ||
439 | +minimally and never achieved the critical size associated with molting by | ||
440 | +conventional and gnotobiotic larvae. In the second part of the study we compared | ||
441 | +patterns of gene expression in conventional, gnotobiotic and axenic larvae by | ||
442 | +conducting an RNAseq analysis of gut and nongut tissues (carcass) at 22 h | ||
443 | +post-hatching. Approximately 12% of Ae. aegypti transcripts were differentially | ||
444 | +expressed in axenic versus conventional or gnotobiotic larvae. However, this | ||
445 | +profile consisted primarily of transcripts in seven categories that included the | ||
446 | +down-regulation of select peptidases in the gut and up-regulation of several | ||
447 | +genes in the gut and carcass with roles in amino acid transport, hormonal | ||
448 | +signaling, and metabolism. Overall, our results indicate that axenic larvae | ||
449 | +exhibit alterations in gene expression consistent with defects in acquisition and | ||
450 | +assimilation of nutrients required for growth. | ||
451 | + | ||
452 | +DOI: 10.1371/journal.pntd.0005273 | ||
453 | +PMCID: PMC5245907 | ||
454 | +PMID: 28060822 [Indexed for MEDLINE] | ||
455 | + | ||
456 | +Conflict of interest statement: The authors have declared that no competing | ||
457 | +interests exist. | ||
458 | + | ||
459 | + | ||
460 | +11. Methods. 2017 Mar 15;117:28-34. doi: 10.1016/j.ymeth.2016.11.011. Epub 2016 Nov | ||
461 | +19. | ||
462 | + | ||
463 | +Identification of unknown RNA partners using MAPS. | ||
464 | + | ||
465 | +Lalaouna D(1), Prévost K(1), Eyraud A(1), Massé E(2). | ||
466 | + | ||
467 | +Author information: | ||
468 | +(1)Department of Biochemistry, RNA Group, Université de Sherbrooke, Sherbrooke, | ||
469 | +Québec J1E 4K8, Canada. | ||
470 | +(2)Department of Biochemistry, RNA Group, Université de Sherbrooke, Sherbrooke, | ||
471 | +Québec J1E 4K8, Canada. Electronic address: eric.masse@usherbrooke.ca. | ||
472 | + | ||
473 | +Recent advances in high-throughput sequencing have led to an explosion in the | ||
474 | +rate of small regulatory RNAs (sRNAs) discovery among bacteria. However, only a | ||
475 | +handful of them are functionally characterized. Most of the time, little to no | ||
476 | +targets are known. In Lalaouna et al. (2015), we proposed a new technology to | ||
477 | +uncover sRNAs targetome, which is based on the MS2-affinity purification (MAPS). | ||
478 | +We were able to prove its efficiency by applying it on well-characterized sRNAs | ||
479 | +of Escherichia coli. Thereafter, we adapted the procedure to other kind of RNA | ||
480 | +(mRNAs and tRNA-derived RNA fragments) and bacteria (pathogenic or Gram-positive | ||
481 | +strains). Here, we clearly report all improvements and adjustments made to MAPS | ||
482 | +technology since it was originally reported. | ||
483 | + | ||
484 | +Copyright © 2016 Elsevier Inc. All rights reserved. | ||
485 | + | ||
486 | +DOI: 10.1016/j.ymeth.2016.11.011 | ||
487 | +PMID: 27876680 [Indexed for MEDLINE] | ||
488 | + | ||
489 | + | ||
490 | +12. FEMS Microbiol Lett. 2017 Jan;364(2). pii: fnw262. doi: 10.1093/femsle/fnw262. | ||
491 | +Epub 2016 Nov 16. | ||
492 | + | ||
493 | +Transcriptional and translational regulation by RNA thermometers, riboswitches | ||
494 | +and the sRNA DsrA in Escherichia coli O157:H7 Sakai under combined cold and | ||
495 | +osmotic stress adaptation. | ||
496 | + | ||
497 | +Hücker SM(1), Simon S(2), Scherer S(1), Neuhaus K(3). | ||
498 | + | ||
499 | +Author information: | ||
500 | +(1)Chair for Microbial Ecology, Technische Universität München, Weihenstephaner | ||
501 | +Berg 3, 85354 Freising, Germany. | ||
502 | +(2)Chair for Data Analysis and Visualization, Department of Computer and | ||
503 | +Information Science, University of Konstanz, Box 78, 78457 Konstanz, Germany. | ||
504 | +(3)Chair for Microbial Ecology, Technische Universität München, Weihenstephaner | ||
505 | +Berg 3, 85354 Freising, Germany neuhaus@wzw.tum.de. | ||
506 | + | ||
507 | +The enteric pathogen Escherichia coli O157:H7 Sakai (EHEC) is able to grow at | ||
508 | +lower temperatures compared to commensal E. coli Growth at environmental | ||
509 | +conditions displays complex challenges different to those in a host. EHEC was | ||
510 | +grown at 37°C and at 14°C with 4% NaCl, a combination of cold and osmotic stress | ||
511 | +as present in the food chain. Comparison of RNAseq and RIBOseq data provided a | ||
512 | +snap shot of ongoing transcription and translation, differentiating | ||
513 | +transcriptional and post-transcriptional gene regulation, respectively. Indeed, | ||
514 | +cold and osmotic stress related genes are simultaneously regulated at both | ||
515 | +levels, but translational regulation clearly dominates. Special emphasis was | ||
516 | +given to genes regulated by RNA secondary structures in their 5'UTRs, such as RNA | ||
517 | +thermometers and riboswitches, or genes controlled by small RNAs encoded in trans | ||
518 | +The results reveal large differences in gene expression between short-time shock | ||
519 | +compared to adaptation in combined cold and osmotic stress. Whereas the majority | ||
520 | +of cold shock proteins, such as CspA, are translationally downregulated after | ||
521 | +adaptation, many osmotic stress genes are still significantly upregulated mainly | ||
522 | +translationally, but several also transcriptionally. | ||
523 | + | ||
524 | +© FEMS 2016. All rights reserved. For permissions, please e-mail: | ||
525 | +journals.permissions@oup.com. | ||
526 | + | ||
527 | +DOI: 10.1093/femsle/fnw262 | ||
528 | +PMID: 27856567 [Indexed for MEDLINE] | ||
529 | + | ||
530 | + | ||
531 | +13. Poult Sci. 2016 Dec 1;95(12):2803-2814. Epub 2016 Jul 27. | ||
532 | + | ||
533 | +Thymus transcriptome reveals novel pathways in response to avian pathogenic | ||
534 | +Escherichia coli infection. | ||
535 | + | ||
536 | +Sun H(1)(2), Liu P(3), Nolan LK(4), Lamont SJ(5). | ||
537 | + | ||
538 | +Author information: | ||
539 | +(1)College of Animal Science and Technology, Yangzhou University, Yangzhou, | ||
540 | +Jiangsu, China, 225009. | ||
541 | +(2)Department of Animal Science, Iowa State University, Ames 50011. | ||
542 | +(3)Department of Statistics, Iowa State University, Ames 50011. | ||
543 | +(4)Department of Veterinary Microbiology and Preventive Medicine, Iowa State | ||
544 | +University, Ames 50011. | ||
545 | +(5)Department of Animal Science, Iowa State University, Ames 50011 | ||
546 | +sjlamont@iastate.edu. | ||
547 | + | ||
548 | +Avian pathogenic Escherichia coli (APEC) can cause significant morbidity in | ||
549 | +chickens. The thymus provides the essential environment for T cell development; | ||
550 | +however, the thymus transcriptome has not been examined for gene expression in | ||
551 | +response to APEC infection. An improved understanding of the host genomic | ||
552 | +response to APEC infection could inform future breeding programs for disease | ||
553 | +resistance and APEC control. We therefore analyzed the transcriptome of the | ||
554 | +thymus of birds challenged with APEC, contrasting susceptible and resistant | ||
555 | +phenotypes. Thousands of genes were differentially expressed in birds of the | ||
556 | +5-day post infection (dpi) challenged-susceptible group vs. 5 dpi non-challenged, | ||
557 | +in 5 dpi challenged-susceptible vs. 5 dpi challenged-resistant birds, as well as | ||
558 | +in 5 dpi vs. one dpi challenged-susceptible birds. The Toll-like receptor | ||
559 | +signaling pathway was the major innate immune response for birds to respond to | ||
560 | +APEC infection. Moreover, lysosome and cell adhesion molecules pathways were | ||
561 | +common mechanisms for chicken response to APEC infection. The T-cell receptor | ||
562 | +signaling pathway, cell cycle, and p53 signaling pathways were significantly | ||
563 | +activated in resistant birds to resist APEC infection. These results provide a | ||
564 | +comprehensive assessment of global gene networks and biological functionalities | ||
565 | +of differentially expressed genes in the thymus under APEC infection. These | ||
566 | +findings provide novel insights into key molecular genetic mechanisms that | ||
567 | +differentiate host resistance from susceptibility in this primary lymphoid | ||
568 | +tissue, the thymus. | ||
569 | + | ||
570 | +© The Author 2016. Published by Oxford University Press on behalf of Poultry | ||
571 | +Science Association. | ||
572 | + | ||
573 | +DOI: 10.3382/ps/pew202 | ||
574 | +PMCID: PMC5144662 | ||
575 | +PMID: 27466434 [Indexed for MEDLINE] | ||
576 | + | ||
577 | + | ||
578 | +14. Sci Rep. 2016 Jul 18;6:30025. doi: 10.1038/srep30025. | ||
579 | + | ||
580 | +Systematic analysis of an evolved Thermobifida fusca muC producing malic acid on | ||
581 | +organic and inorganic nitrogen sources. | ||
582 | + | ||
583 | +Deng Y(1)(2), Lin J(3), Mao Y(1)(2), Zhang X(4). | ||
584 | + | ||
585 | +Author information: | ||
586 | +(1)National Engineering Laboratory for Cereal Fermentation Technology (NELCF), | ||
587 | +Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China. | ||
588 | +(2)The Key Laboratory of Industrial Biotechnology, Ministry of Education, | ||
589 | +Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China. | ||
590 | +(3)College of Life Science, North China University of Science and Technology, | ||
591 | +Tangshan 063000, China. | ||
592 | +(4)School of pharmaceutical science, Jiangnan University, 1800 Lihu Road, Wuxi, | ||
593 | +Jiangsu 214122, China. | ||
594 | + | ||
595 | +Thermobifida fusca is a thermophilic actinobacterium. T. fusca muC obtained by | ||
596 | +adaptive evolution preferred yeast extract to ammonium sulfate for accumulating | ||
597 | +malic acid and ammonium sulfate for cell growth. We did transcriptome analysis of | ||
598 | +T. fusca muC on Avicel and cellobiose with addition of ammonium sulfate or yeast | ||
599 | +extract, respectively by RNAseq. The transcriptional results indicate that | ||
600 | +ammonium sulfate induced the transcriptions of the genes related to carbohydrate | ||
601 | +metabolisms significantly more than yeast extract. Importantly, Tfu_2487, | ||
602 | +encoding histidine-containing protein (HPr), didn't transcribe on yeast extract | ||
603 | +at all, while it transcribed highly on ammonium sulfate. In order to understand | ||
604 | +the impact of HPr on malate production and cell growth of the muC strain, we | ||
605 | +deleted Tfu_2487 to get a mutant strain: muCΔ2487, which had | ||
606 | +1.33 mole/mole-glucose equivalent malate yield, much higher than that on yeast | ||
607 | +extract. We then developed an E. coli-T. fusca shuttle plasmid for | ||
608 | +over-expressing HPr in muCΔ2487, a strain without HPr background, forming the | ||
609 | +muCΔ2487S strain. The muCΔ2487S strain had a much lower malate yield but faster | ||
610 | +cell growth than the muC strain. The results of both mutant strains confirmed | ||
611 | +that HPr was the key regulatory protein for T. fusca's metabolisms on nitrogen | ||
612 | +sources. | ||
613 | + | ||
614 | +DOI: 10.1038/srep30025 | ||
615 | +PMCID: PMC4948018 | ||
616 | +PMID: 27424527 | ||
617 | + | ||
618 | + | ||
619 | +15. PLoS One. 2016 Jun 23;11(6):e0157480. doi: 10.1371/journal.pone.0157480. | ||
620 | +eCollection 2016. | ||
621 | + | ||
622 | +The Impact of Intramammary Escherichia coli Challenge on Liver and Mammary | ||
623 | +Transcriptome and Cross-Talk in Dairy Cows during Early Lactation Using RNAseq. | ||
624 | + | ||
625 | +Moyes KM(1), Sørensen P(2), Bionaz M(3). | ||
626 | + | ||
627 | +Author information: | ||
628 | +(1)Department of Animal and Avian Sciences, University of Maryland, College Park, | ||
629 | +Maryland, United States of America. | ||
630 | +(2)Center for Quantitative Genetics and Genomics, Department of Molecular Biology | ||
631 | +and Genetics, Aarhus University, 8830 Tjele, Denmark. | ||
632 | +(3)Department of Animal and Rangeland Sciences, Oregon State University, | ||
633 | +Corvallis, Oregon, United States of America. | ||
634 | + | ||
635 | +Our objective was to identify the biological response and the cross-talk between | ||
636 | +liver and mammary tissue after intramammary infection (IMI) with Escherichia coli | ||
637 | +(E. coli) using RNAseq technology. Sixteen cows were inoculated with live E. coli | ||
638 | +into one mammary quarter at ~4-6 weeks in lactation. For all cows, biopsies were | ||
639 | +performed at -144, 12 and 24 h relative to IMI in liver and at 24 h post-IMI in | ||
640 | +infected and non-infected (control) mammary quarters. For a subset of cows (n = | ||
641 | +6), RNA was extracted from both liver and mammary tissue and sequenced using a | ||
642 | +100 bp paired-end approach. Ingenuity Pathway Analysis and the Dynamic Impact | ||
643 | +Approach analysis of differentially expressed genes (overall effect False | ||
644 | +Discovery Rate≤0.05) indicated that IMI induced an overall activation of | ||
645 | +inflammation at 12 h post-IMI and a strong inhibition of metabolism, especially | ||
646 | +related to lipid, glucose, and xenobiotics at 24 h post-IMI in liver. The data | ||
647 | +indicated in mammary tissue an overall induction of inflammatory response with | ||
648 | +little effect on metabolism at 24 h post-IMI. We identified a large number of | ||
649 | +up-stream regulators potentially involved in the response to IMI in both tissues | ||
650 | +but a relatively small core network of transcription factors controlling the | ||
651 | +response to IMI for liver whereas a large network in mammary tissue. | ||
652 | +Transcriptomic results in liver and mammary tissue were supported by changes in | ||
653 | +inflammatory and metabolic mediators in blood and milk. The analysis of potential | ||
654 | +cross-talk between the two tissues during IMI uncovered a large communication | ||
655 | +from the mammary tissue to the liver to coordinate the inflammatory response but | ||
656 | +a relatively small communication from the liver to the mammary tissue. Our | ||
657 | +results indicate a strong induction of the inflammatory response in mammary | ||
658 | +tissue and impairment of liver metabolism 24h post-IMI partly driven by the | ||
659 | +signaling from infected mammary tissue. | ||
660 | + | ||
661 | +DOI: 10.1371/journal.pone.0157480 | ||
662 | +PMCID: PMC4919052 | ||
663 | +PMID: 27336699 [Indexed for MEDLINE] | ||
664 | + | ||
665 | + | ||
666 | +16. BMC Genomics. 2016 Feb 24;17:133. doi: 10.1186/s12864-016-2456-1. | ||
667 | + | ||
668 | +Translatomics combined with transcriptomics and proteomics reveals novel | ||
669 | +functional, recently evolved orphan genes in Escherichia coli O157:H7 (EHEC). | ||
670 | + | ||
671 | +Neuhaus K(1), Landstorfer R(2), Fellner L(3), Simon S(4), Schafferhans A(5), | ||
672 | +Goldberg T(6), Marx H(7), Ozoline ON(8), Rost B(9), Kuster B(10)(11), Keim | ||
673 | +DA(12), Scherer S(13). | ||
674 | + | ||
675 | +Author information: | ||
676 | +(1)Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und | ||
677 | +Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität | ||
678 | +München, Weihenstephaner Berg 3, 85354, Freising, Germany. neuhaus@wzw.tum.de. | ||
679 | +(2)Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und | ||
680 | +Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität | ||
681 | +München, Weihenstephaner Berg 3, 85354, Freising, Germany. r.landstorfer@gmx.de. | ||
682 | +(3)Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und | ||
683 | +Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität | ||
684 | +München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
685 | +fellnerlea@hotmail.com. | ||
686 | +(4)Lehrstuhl für Datenanalyse und Visualisierung, Fachbereich Informatik und | ||
687 | +Informationswissenschaft, Universität Konstanz, Box 78, 78457, Konstanz, Germany. | ||
688 | +simon@dbvis.inf.uni-konstanz.de. | ||
689 | +(5)Department of Informatics - Bioinformatics & TUM-IAS, Technische Universität | ||
690 | +München, Boltzmannstraße 3, 85748, Garching, Germany. | ||
691 | +andrea.schafferhans@rostlab.org. | ||
692 | +(6)Department of Informatics - Bioinformatics & TUM-IAS, Technische Universität | ||
693 | +München, Boltzmannstraße 3, 85748, Garching, Germany. goldberg@rostlab.org. | ||
694 | +(7)Chair of Proteomics and Bioanalytics, Wissenschaftszentrum Weihenstephan, | ||
695 | +Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, | ||
696 | +Germany. h4r4ld.marx@googlemail.com. | ||
697 | +(8)Institute of Cell Biophysics, Russian Academy of Sciences, Moscow Region, | ||
698 | +142290, Pushchino, Russia. ozoline@rambler.ru. | ||
699 | +(9)Department of Informatics - Bioinformatics & TUM-IAS, Technische Universität | ||
700 | +München, Boltzmannstraße 3, 85748, Garching, Germany. rost@rostlab.org. | ||
701 | +(10)Chair of Proteomics and Bioanalytics, Wissenschaftszentrum Weihenstephan, | ||
702 | +Technische Universität München, Emil-Erlenmeyer-Forum 5, 85354, Freising, | ||
703 | +Germany. kuster@wzw.tum.de. | ||
704 | +(11)Bavarian Center for Biomolecular Mass Spectrometry (BayBioMS), Technische | ||
705 | +Universität München, Gregor-Mendel-Str. 4, 85354, Freising, Germany. | ||
706 | +kuster@wzw.tum.de. | ||
707 | +(12)Lehrstuhl für Datenanalyse und Visualisierung, Fachbereich Informatik und | ||
708 | +Informationswissenschaft, Universität Konstanz, Box 78, 78457, Konstanz, Germany. | ||
709 | +keim@informatik.uni-konstanz.de. | ||
710 | +(13)Lehrstuhl für Mikrobielle Ökologie, Zentralinstitut für Ernährungs- und | ||
711 | +Lebensmittelforschung, Wissenschaftszentrum Weihenstephan, Technische Universität | ||
712 | +München, Weihenstephaner Berg 3, 85354, Freising, Germany. | ||
713 | +siegfried.scherer@wzw.tum.de. | ||
714 | + | ||
715 | +BACKGROUND: Genomes of E. coli, including that of the human pathogen Escherichia | ||
716 | +coli O157:H7 (EHEC) EDL933, still harbor undetected protein-coding genes which, | ||
717 | +apparently, have escaped annotation due to their small size and non-essential | ||
718 | +function. To find such genes, global gene expression of EHEC EDL933 was examined, | ||
719 | +using strand-specific RNAseq (transcriptome), ribosomal footprinting | ||
720 | +(translatome) and mass spectrometry (proteome). | ||
721 | +RESULTS: Using the above methods, 72 short, non-annotated protein-coding genes | ||
722 | +were detected. All of these showed signals in the ribosomal footprinting assay | ||
723 | +indicating mRNA translation. Seven were verified by mass spectrometry. | ||
724 | +Fifty-seven genes are annotated in other enterobacteriaceae, mainly as | ||
725 | +hypothetical genes; the remaining 15 genes constitute novel discoveries. In | ||
726 | +addition, protein structure and function were predicted computationally and | ||
727 | +compared between EHEC-encoded proteins and 100-times randomly shuffled proteins. | ||
728 | +Based on this comparison, 61 of the 72 novel proteins exhibit predicted | ||
729 | +structural and functional features similar to those of annotated proteins. Many | ||
730 | +of the novel genes show differential transcription when grown under eleven | ||
731 | +diverse growth conditions suggesting environmental regulation. Three genes were | ||
732 | +found to confer a phenotype in previous studies, e.g., decreased cattle | ||
733 | +colonization. | ||
734 | +CONCLUSIONS: These findings demonstrate that ribosomal footprinting can be used | ||
735 | +to detect novel protein coding genes, contributing to the growing body of | ||
736 | +evidence that hypothetical genes are not annotation artifacts and opening an | ||
737 | +additional way to study their functionality. All 72 genes are taxonomically | ||
738 | +restricted and, therefore, appear to have evolved relatively recently de novo. | ||
739 | + | ||
740 | +DOI: 10.1186/s12864-016-2456-1 | ||
741 | +PMCID: PMC4765031 | ||
742 | +PMID: 26911138 [Indexed for MEDLINE] | ||
743 | + | ||
744 | + | ||
745 | +17. Sci Rep. 2016 Jan 28;6:19899. doi: 10.1038/srep19899. | ||
746 | + | ||
747 | +Global transcriptomic responses of Escherichia coli K-12 to volatile organic | ||
748 | +compounds. | ||
749 | + | ||
750 | +Yung PY(1), Grasso LL(1), Mohidin AF(1), Acerbi E(1), Hinks J(1), Seviour T(1), | ||
751 | +Marsili E(1)(2)(3), Lauro FM(1)(4). | ||
752 | + | ||
753 | +Author information: | ||
754 | +(1)Singapore Centre for Environmental Life Sciences Engineering (SCELSE). 60 | ||
755 | +Nanyang Drive, SBS-01N-27, Singapore 637551. | ||
756 | +(2)School of Chemical and Biomedical Engineering, Nanyang Technological | ||
757 | +University, 62 Nanyang Drive, Singapore 637459. | ||
758 | +(3)School of Biotechnology, Dublin City University, Collins Avenue, Dublin 9, | ||
759 | +Ireland. | ||
760 | +(4)Asian School of the Environment, Nanyang Technological University, 50 Nanyang | ||
761 | +Avenue, N2-01C-45, Singapore 639798. | ||
762 | + | ||
763 | +Volatile organic compounds (VOCs) are commonly used as solvents in various | ||
764 | +industrial settings. Many of them present a challenge to receiving environments, | ||
765 | +due to their toxicity and low bioavailability for degradation. Microorganisms are | ||
766 | +capable of sensing and responding to their surroundings and this makes them ideal | ||
767 | +detectors for toxic compounds. This study investigates the global transcriptomic | ||
768 | +responses of Escherichia coli K-12 to selected VOCs at sub-toxic levels. Cells | ||
769 | +grown in the presence of VOCs were harvested during exponential growth, followed | ||
770 | +by whole transcriptome shotgun sequencing (RNAseq). The analysis of the data | ||
771 | +revealed both shared and unique genetic responses compared to cells without | ||
772 | +exposure to VOCs. Results suggest that various functional gene categories, for | ||
773 | +example, those relating to Fe/S cluster biogenesis, oxidative stress responses | ||
774 | +and transport proteins, are responsive to selected VOCs in E. coli. The | ||
775 | +differential expression (DE) of genes was validated using GFP-promoter fusion | ||
776 | +assays. A variety of genes were differentially expressed even at non-inhibitory | ||
777 | +concentrations and when the cells are at their balanced-growth. Some of these | ||
778 | +genes belong to generic stress response and others could be specific to VOCs. | ||
779 | +Such candidate genes and their regulatory elements could be used as the basis for | ||
780 | +designing biosensors for selected VOCs. | ||
781 | + | ||
782 | +DOI: 10.1038/srep19899 | ||
783 | +PMCID: PMC4730218 | ||
784 | +PMID: 26818886 [Indexed for MEDLINE] | ||
785 | + | ||
786 | + | ||
787 | +18. MBio. 2015 Aug 25;6(4). pii: e00998-15. doi: 10.1128/mBio.00998-15. | ||
788 | + | ||
789 | +A New Noncoding RNA Arranges Bacterial Chromosome Organization. | ||
790 | + | ||
791 | +Qian Z(1), Macvanin M(1), Dimitriadis EK(2), He X(3), Zhurkin V(4), Adhya S(5). | ||
792 | + | ||
793 | +Author information: | ||
794 | +(1)Laboratory of Molecular Biology, National Cancer Institute, National | ||
795 | +Institutes of Health, Bethesda, Maryland, USA. | ||
796 | +(2)Biomedical Engineering and Physical Science, National Institute of Biomedical | ||
797 | +Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland, | ||
798 | +USA. | ||
799 | +(3)Laboratory of Metabolism, National Cancer Institute, National Institutes of | ||
800 | +Health, Bethesda, Maryland, USA. | ||
801 | +(4)Laboratory of Cell Biology, National Cancer Institute, National Institutes of | ||
802 | +Health, Bethesda, Maryland, USA. | ||
803 | +(5)Laboratory of Molecular Biology, National Cancer Institute, National | ||
804 | +Institutes of Health, Bethesda, Maryland, USA sadhya@helix.nih.gov. | ||
805 | + | ||
806 | +Repeated extragenic palindromes (REPs) in the enterobacterial genomes are usually | ||
807 | +composed of individual palindromic units separated by linker sequences. A total | ||
808 | +of 355 annotated REPs are distributed along the Escherichia coli genome. RNA | ||
809 | +sequence (RNAseq) analysis showed that almost 80% of the REPs in E. coli are | ||
810 | +transcribed. The DNA sequence of REP325 showed that it is a cluster of six | ||
811 | +repeats, each with two palindromic units capable of forming cruciform structures | ||
812 | +in supercoiled DNA. Here, we report that components of the REP325 element and at | ||
813 | +least one of its RNA products play a role in bacterial nucleoid DNA condensation. | ||
814 | +These RNA not only are present in the purified nucleoid but bind to the bacterial | ||
815 | +nucleoid-associated HU protein as revealed by RNA IP followed by microarray | ||
816 | +analysis (RIP-Chip) assays. Deletion of REP325 resulted in a dramatic increase of | ||
817 | +the nucleoid size as observed using transmission electron microscopy (TEM), and | ||
818 | +expression of one of the REP325 RNAs, nucleoid-associated noncoding RNA 4 | ||
819 | +(naRNA4), from a plasmid restored the wild-type condensed structure. | ||
820 | +Independently, chromosome conformation capture (3C) analysis demonstrated | ||
821 | +physical connections among various REP elements around the chromosome. These | ||
822 | +connections are dependent in some way upon the presence of HU and the REP325 | ||
823 | +element; deletion of HU genes and/or the REP325 element removed the connections. | ||
824 | +Finally, naRNA4 together with HU condensed DNA in vitro by connecting REP325 or | ||
825 | +other DNA sequences that contain cruciform structures in a pairwise manner as | ||
826 | +observed by atomic force microscopy (AFM). On the basis of our results, we | ||
827 | +propose molecular models to explain connections of remote cruciform structures | ||
828 | +mediated by HU and naRNA4.IMPORTANCE: Nucleoid organization in bacteria is being | ||
829 | +studied extensively, and several models have been proposed. However, the | ||
830 | +molecular nature of the structural organization is not well understood. Here we | ||
831 | +characterized the role of a novel nucleoid-associated noncoding RNA, naRNA4, in | ||
832 | +nucleoid structures both in vivo and in vitro. We propose models to explain how | ||
833 | +naRNA4 together with nucleoid-associated protein HU connects remote DNA elements | ||
834 | +for nucleoid condensation. We present the first evidence of a noncoding RNA | ||
835 | +together with a nucleoid-associated protein directly condensing nucleoid DNA. | ||
836 | + | ||
837 | +Copyright © 2015 Qian et al. | ||
838 | + | ||
839 | +DOI: 10.1128/mBio.00998-15 | ||
840 | +PMCID: PMC4550694 | ||
841 | +PMID: 26307168 [Indexed for MEDLINE] | ||
842 | + | ||
843 | + | ||
844 | +19. PLoS One. 2015 Jun 30;10(6):e0130902. doi: 10.1371/journal.pone.0130902. | ||
845 | +eCollection 2015. | ||
846 | + | ||
847 | +Identification of Candidate Adherent-Invasive E. coli Signature Transcripts by | ||
848 | +Genomic/Transcriptomic Analysis. | ||
849 | + | ||
850 | +Zhang Y(1), Rowehl L(2), Krumsiek JM(3), Orner EP(2), Shaikh N(4), Tarr PI(5), | ||
851 | +Sodergren E(6), Weinstock GM(6), Boedeker EC(7), Xiong X(8), Parkinson J(9), | ||
852 | +Frank DN(10), Li E(2), Gathungu G(3). | ||
853 | + | ||
854 | +Author information: | ||
855 | +(1)Department of Applied Mathematics and Statistics, Stony Brook University, | ||
856 | +Stony Brook, New York, United States of America. | ||
857 | +(2)Department of Medicine, Stony Brook University, Stony Brook, New York, United | ||
858 | +States of America. | ||
859 | +(3)Department of Pediatrics, Stony Brook University, Stony Brook, New York, | ||
860 | +United States of America. | ||
861 | +(4)Department of Pediatrics, Washington University St. Louis, St. Louis, | ||
862 | +Missouri, United States of America. | ||
863 | +(5)Department of Pediatrics, Washington University St. Louis, St. Louis, | ||
864 | +Missouri, United States of America; Department of Molecular Microbiology, | ||
865 | +Washington University St. Louis, St. Louis, Missouri, United States of America. | ||
866 | +(6)The Genome Institute, Washington University St. Louis, St. Louis, Missouri, | ||
867 | +United States of America. | ||
868 | +(7)Department of Medicine, University of New Mexico, Albuquerque, New Mexico, | ||
869 | +United States of America. | ||
870 | +(8)Program in Molecular Structure and Function, The Hospital for Sick Children, | ||
871 | +Toronto, Canada. | ||
872 | +(9)Department of Biochemistry & Molecular and Medical Genetics, University of | ||
873 | +Toronto, Toronto, Canada. | ||
874 | +(10)Department of Medicine, University of Colorado, Denver, Colorado, United | ||
875 | +States of America. | ||
876 | + | ||
877 | +Erratum in | ||
878 | + PLoS One. 2015;10(7):e0134759. | ||
879 | + | ||
880 | +Adherent-invasive Escherichia coli (AIEC) strains are detected more frequently | ||
881 | +within mucosal lesions of patients with Crohn's disease (CD). The AIEC phenotype | ||
882 | +consists of adherence and invasion of intestinal epithelial cells and survival | ||
883 | +within macrophages of these bacteria in vitro. Our aim was to identify candidate | ||
884 | +transcripts that distinguish AIEC from non-invasive E. coli (NIEC) strains and | ||
885 | +might be useful for rapid and accurate identification of AIEC by | ||
886 | +culture-independent technology. We performed comparative RNA-Sequence (RNASeq) | ||
887 | +analysis using AIEC strain LF82 and NIEC strain HS during exponential and | ||
888 | +stationary growth. Differential expression analysis of coding sequences (CDS) | ||
889 | +homologous to both strains demonstrated 224 and 241 genes with increased and | ||
890 | +decreased expression, respectively, in LF82 relative to HS. Transition metal | ||
891 | +transport and siderophore metabolism related pathway genes were up-regulated, | ||
892 | +while glycogen metabolic and oxidation-reduction related pathway genes were | ||
893 | +down-regulated, in LF82. Chemotaxis related transcripts were up-regulated in LF82 | ||
894 | +during the exponential phase, but flagellum-dependent motility pathway genes were | ||
895 | +down-regulated in LF82 during the stationary phase. CDS that mapped only to the | ||
896 | +LF82 genome accounted for 747 genes. We applied an in silico subtractive genomics | ||
897 | +approach to identify CDS specific to AIEC by incorporating the genomes of 10 | ||
898 | +other previously phenotyped NIEC. From this analysis, 166 CDS mapped to the LF82 | ||
899 | +genome and lacked homology to any of the 11 human NIEC strains. We compared these | ||
900 | +CDS across 13 AIEC, but none were homologous in each. Four LF82 gene loci | ||
901 | +belonging to clustered regularly interspaced short palindromic repeats region | ||
902 | +(CRISPR)--CRISPR-associated (Cas) genes were identified in 4 to 6 AIEC and absent | ||
903 | +from all non-pathogenic bacteria. As previously reported, AIEC strains were | ||
904 | +enriched for pdu operon genes. One CDS, encoding an excisionase, was shared by 9 | ||
905 | +AIEC strains. Reverse transcription quantitative polymerase chain reaction assays | ||
906 | +for 6 genes were conducted on fecal and ileal RNA samples from 22 inflammatory | ||
907 | +bowel disease (IBD), and 32 patients without IBD (non-IBD). The expression of Cas | ||
908 | +loci was detected in a higher proportion of CD than non-IBD fecal and ileal RNA | ||
909 | +samples (p <0.05). These results support a comparative genomic/transcriptomic | ||
910 | +approach towards identifying candidate AIEC signature transcripts. | ||
911 | + | ||
912 | +DOI: 10.1371/journal.pone.0130902 | ||
913 | +PMCID: PMC4509574 | ||
914 | +PMID: 26125937 [Indexed for MEDLINE] | ||
915 | + | ||
916 | + | ||
917 | +20. Front Microbiol. 2014 Aug 13;5:402. doi: 10.3389/fmicb.2014.00402. eCollection | ||
918 | +2014. | ||
919 | + | ||
920 | +Aromatic inhibitors derived from ammonia-pretreated lignocellulose hinder | ||
921 | +bacterial ethanologenesis by activating regulatory circuits controlling inhibitor | ||
922 | +efflux and detoxification. | ||
923 | + | ||
924 | +Keating DH(1), Zhang Y(1), Ong IM(1), McIlwain S(1), Morales EH(2), Grass JA(3), | ||
925 | +Tremaine M(1), Bothfeld W(1), Higbee A(1), Ulbrich A(4), Balloon AJ(4), Westphall | ||
926 | +MS(5), Aldrich J(6), Lipton MS(6), Kim J(7), Moskvin OV(1), Bukhman YV(1), Coon | ||
927 | +JJ(8), Kiley PJ(2), Bates DM(1), Landick R(9). | ||
928 | + | ||
929 | +Author information: | ||
930 | +(1)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
931 | +Madison, WI, USA. | ||
932 | +(2)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
933 | +Madison, WI, USA ; Department of Biomolecular Chemistry, University of | ||
934 | +Wisconsin-Madison Madison, WI, USA. | ||
935 | +(3)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
936 | +Madison, WI, USA ; Department of Biochemistry, University of Wisconsin-Madison | ||
937 | +Madison, WI, USA. | ||
938 | +(4)Department of Chemistry, University of Wisconsin-Madison Madison, WI, USA. | ||
939 | +(5)Department of Biomolecular Chemistry, University of Wisconsin-Madison Madison, | ||
940 | +WI, USA ; Department of Chemistry, University of Wisconsin-Madison Madison, WI, | ||
941 | +USA. | ||
942 | +(6)Pacific Northwest National Laboratory Richland, WA, USA. | ||
943 | +(7)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
944 | +Madison, WI, USA ; Department of Chemical and Biological Engineering, University | ||
945 | +of Wisconsin-Madison Madison, WI, USA. | ||
946 | +(8)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
947 | +Madison, WI, USA ; Department of Biomolecular Chemistry, University of | ||
948 | +Wisconsin-Madison Madison, WI, USA ; Department of Chemistry, University of | ||
949 | +Wisconsin-Madison Madison, WI, USA. | ||
950 | +(9)Great Lakes Bioenergy Research Center, University of Wisconsin-Madison | ||
951 | +Madison, WI, USA ; Department of Biochemistry, University of Wisconsin-Madison | ||
952 | +Madison, WI, USA ; Department of Bacteriology, University of Wisconsin-Madison | ||
953 | +Madison, WI, USA. | ||
954 | + | ||
955 | +Efficient microbial conversion of lignocellulosic hydrolysates to biofuels is a | ||
956 | +key barrier to the economically viable deployment of lignocellulosic biofuels. A | ||
957 | +chief contributor to this barrier is the impact on microbial processes and energy | ||
958 | +metabolism of lignocellulose-derived inhibitors, including phenolic carboxylates, | ||
959 | +phenolic amides (for ammonia-pretreated biomass), phenolic aldehydes, and | ||
960 | +furfurals. To understand the bacterial pathways induced by inhibitors present in | ||
961 | +ammonia-pretreated biomass hydrolysates, which are less well studied than | ||
962 | +acid-pretreated biomass hydrolysates, we developed and exploited synthetic mimics | ||
963 | +of ammonia-pretreated corn stover hydrolysate (ACSH). To determine regulatory | ||
964 | +responses to the inhibitors normally present in ACSH, we measured transcript and | ||
965 | +protein levels in an Escherichia coli ethanologen using RNA-seq and quantitative | ||
966 | +proteomics during fermentation to ethanol of synthetic hydrolysates containing or | ||
967 | +lacking the inhibitors. Our study identified four major regulators mediating | ||
968 | +these responses, the MarA/SoxS/Rob network, AaeR, FrmR, and YqhC. Induction of | ||
969 | +these regulons was correlated with a reduced rate of ethanol production, buildup | ||
970 | +of pyruvate, depletion of ATP and NAD(P)H, and an inhibition of xylose | ||
971 | +conversion. The aromatic aldehyde inhibitor 5-hydroxymethylfurfural appeared to | ||
972 | +be reduced to its alcohol form by the ethanologen during fermentation, whereas | ||
973 | +phenolic acid and amide inhibitors were not metabolized. Together, our findings | ||
974 | +establish that the major regulatory responses to lignocellulose-derived | ||
975 | +inhibitors are mediated by transcriptional rather than translational regulators, | ||
976 | +suggest that energy consumed for inhibitor efflux and detoxification may limit | ||
977 | +biofuel production, and identify a network of regulators for future synthetic | ||
978 | +biology efforts. | ||
979 | + | ||
980 | +DOI: 10.3389/fmicb.2014.00402 | ||
981 | +PMCID: PMC4132294 | ||
982 | +PMID: 25177315 | ||
983 | + | ||
984 | + | ||
985 | +21. BMC Microbiol. 2014 Aug 1;14:206. doi: 10.1186/s12866-014-0206-6. | ||
986 | + | ||
987 | +Characterization and analysis of the Burkholderia pseudomallei BsaN virulence | ||
988 | +regulon. | ||
989 | + | ||
990 | +Chen Y, Schröder I, French CT, Jaroszewicz A, Yee XJ, Teh BE, Toesca IJ, Miller | ||
991 | +JF, Gan YH(1). | ||
992 | + | ||
993 | +Author information: | ||
994 | +(1)Department of Biochemistry, Yong Loo Lin School of Medicine, National | ||
995 | +University of Singapore, Singapore 117597, Singapore. yunn_hwen_gan@nuhs.edu.sg. | ||
996 | + | ||
997 | +BACKGROUND: Burkholderia pseudomallei is a facultative intracellular pathogen and | ||
998 | +the causative agent of melioidosis. A conserved type III secretion system (T3SS3) | ||
999 | +and type VI secretion system (T6SS1) are critical for intracellular survival and | ||
1000 | +growth. The T3SS3 and T6SS1 genes are coordinately and hierarchically regulated | ||
1001 | +by a TetR-type regulator, BspR. A central transcriptional regulator of the BspR | ||
1002 | +regulatory cascade, BsaN, activates a subset of T3SS3 and T6SS1 loci. | ||
1003 | +RESULTS: To elucidate the scope of the BsaN regulon, we used RNAseq analysis to | ||
1004 | +compare the transcriptomes of wild-type B. pseudomallei KHW and a bsaN deletion | ||
1005 | +mutant. The 60 genes positively-regulated by BsaN include those that we had | ||
1006 | +previously identified in addition to a polyketide biosynthesis locus and genes | ||
1007 | +involved in amino acid biosynthesis. BsaN was also found to repress the | ||
1008 | +transcription of 51 genes including flagellar motility loci and those encoding | ||
1009 | +components of the T3SS3 apparatus. Using a promoter-lacZ fusion assay in E. coli, | ||
1010 | +we show that BsaN together with the chaperone BicA directly control the | ||
1011 | +expression of the T3SS3 translocon, effector and associated regulatory genes that | ||
1012 | +are organized into at least five operons (BPSS1516-BPSS1552). Using a mutagenesis | ||
1013 | +approach, a consensus regulatory motif in the promoter regions of BsaN-regulated | ||
1014 | +genes was shown to be essential for transcriptional activation. | ||
1015 | +CONCLUSIONS: BsaN/BicA functions as a central regulator of key virulence clusters | ||
1016 | +in B. pseudomallei within a more extensive network of genetic regulation. We | ||
1017 | +propose that BsaN/BicA controls a gene expression program that facilitates the | ||
1018 | +adaption and intracellular survival of the pathogen within eukaryotic hosts. | ||
1019 | + | ||
1020 | +DOI: 10.1186/s12866-014-0206-6 | ||
1021 | +PMCID: PMC4236580 | ||
1022 | +PMID: 25085508 [Indexed for MEDLINE] | ||
1023 | + | ||
1024 | + | ||
1025 | +22. Proc Natl Acad Sci U S A. 2014 Jun 24;111(25):E2576-85. doi: | ||
1026 | +10.1073/pnas.1401853111. Epub 2014 Jun 9. | ||
1027 | + | ||
1028 | +Correcting direct effects of ethanol on translation and transcription machinery | ||
1029 | +confers ethanol tolerance in bacteria. | ||
1030 | + | ||
1031 | +Haft RJ(1), Keating DH(1), Schwaegler T(1), Schwalbach MS(1), Vinokur J(1), | ||
1032 | +Tremaine M(1), Peters JM(2), Kotlajich MV(3), Pohlmann EL(1), Ong IM(1), Grass | ||
1033 | +JA(1), Kiley PJ(4), Landick R(5). | ||
1034 | + | ||
1035 | +Author information: | ||
1036 | +(1)Great Lakes Bioenergy Research Center and. | ||
1037 | +(2)Departments of Biochemistry,Genetics. | ||
1038 | +(3)Departments of Biochemistry. | ||
1039 | +(4)Great Lakes Bioenergy Research Center andBiomolecular Chemistry, and. | ||
1040 | +(5)Great Lakes Bioenergy Research Center andDepartments of | ||
1041 | +Biochemistry,Bacteriology, University of Wisconsin-Madison, Madison, WI 53706 | ||
1042 | +landick@biochem.wisc.edu. | ||
1043 | + | ||
1044 | +The molecular mechanisms of ethanol toxicity and tolerance in bacteria, although | ||
1045 | +important for biotechnology and bioenergy applications, remain incompletely | ||
1046 | +understood. Genetic studies have identified potential cellular targets for | ||
1047 | +ethanol and have revealed multiple mechanisms of tolerance, but it remains | ||
1048 | +difficult to separate the direct and indirect effects of ethanol. We used | ||
1049 | +adaptive evolution to generate spontaneous ethanol-tolerant strains of | ||
1050 | +Escherichia coli, and then characterized mechanisms of toxicity and resistance | ||
1051 | +using genome-scale DNAseq, RNAseq, and ribosome profiling coupled with specific | ||
1052 | +assays of ribosome and RNA polymerase function. Evolved alleles of metJ, rho, and | ||
1053 | +rpsQ recapitulated most of the observed ethanol tolerance, implicating | ||
1054 | +translation and transcription as key processes affected by ethanol. Ethanol | ||
1055 | +induced miscoding errors during protein synthesis, from which the evolved rpsQ | ||
1056 | +allele protected cells by increasing ribosome accuracy. Ribosome profiling and | ||
1057 | +RNAseq analyses established that ethanol negatively affects transcriptional and | ||
1058 | +translational processivity. Ethanol-stressed cells exhibited ribosomal stalling | ||
1059 | +at internal AUG codons, which may be ameliorated by the adaptive inactivation of | ||
1060 | +the MetJ repressor of methionine biosynthesis genes. Ethanol also caused aberrant | ||
1061 | +intragenic transcription termination for mRNAs with low ribosome density, which | ||
1062 | +was reduced in a strain with the adaptive rho mutation. Furthermore, ethanol | ||
1063 | +inhibited transcript elongation by RNA polymerase in vitro. We propose that | ||
1064 | +ethanol-induced inhibition and uncoupling of mRNA and protein synthesis through | ||
1065 | +direct effects on ribosomes and RNA polymerase conformations are major | ||
1066 | +contributors to ethanol toxicity in E. coli, and that adaptive mutations in metJ, | ||
1067 | +rho, and rpsQ help protect these central dogma processes in the presence of | ||
1068 | +ethanol. | ||
1069 | + | ||
1070 | +DOI: 10.1073/pnas.1401853111 | ||
1071 | +PMCID: PMC4078849 | ||
1072 | +PMID: 24927582 [Indexed for MEDLINE] | ||
1073 | + | ||
1074 | + | ||
1075 | +23. Nucleic Acids Res. 2013 Jan;41(Database issue):D1-7. doi: 10.1093/nar/gks1297. | ||
1076 | +Epub 2012 Nov 30. | ||
1077 | + | ||
1078 | +The 2013 Nucleic Acids Research Database Issue and the online molecular biology | ||
1079 | +database collection. | ||
1080 | + | ||
1081 | +Fernández-Suárez XM(1), Galperin MY. | ||
1082 | + | ||
1083 | +Author information: | ||
1084 | +(1)nardatabase@gmail.com | ||
1085 | + | ||
1086 | +The 20th annual Database Issue of Nucleic Acids Research includes 176 articles, | ||
1087 | +half of which describe new online molecular biology databases and the other half | ||
1088 | +provide updates on the databases previously featured in NAR and other journals. | ||
1089 | +This year's highlights include two databases of DNA repeat elements; several | ||
1090 | +databases of transcriptional factors and transcriptional factor-binding sites; | ||
1091 | +databases on various aspects of protein structure and protein-protein | ||
1092 | +interactions; databases for metagenomic and rRNA sequence analysis; and four | ||
1093 | +databases specifically dedicated to Escherichia coli. The increased emphasis on | ||
1094 | +using the genome data to improve human health is reflected in the development of | ||
1095 | +the databases of genomic structural variation (NCBI's dbVar and EBI's DGVa), the | ||
1096 | +NIH Genetic Testing Registry and several other databases centered on the genetic | ||
1097 | +basis of human disease, potential drugs, their targets and the mechanisms of | ||
1098 | +protein-ligand binding. Two new databases present genomic and RNAseq data for | ||
1099 | +monkeys, providing wealth of data on our closest relatives for comparative | ||
1100 | +genomics purposes. The NAR online Molecular Biology Database Collection, | ||
1101 | +available at http://www.oxfordjournals.org/nar/database/a/, has been updated and | ||
1102 | +currently lists 1512 online databases. The full content of the Database Issue is | ||
1103 | +freely available online on the Nucleic Acids Research website | ||
1104 | +(http://nar.oxfordjournals.org/). | ||
1105 | + | ||
1106 | +DOI: 10.1093/nar/gks1297 | ||
1107 | +PMCID: PMC3531151 | ||
1108 | +PMID: 23203983 [Indexed for MEDLINE] | ||
1109 | + | ||
1110 | + | ||
1111 | +24. Nucleic Acids Res. 2012 Nov 1;40(20):e156. doi: 10.1093/nar/gks680. Epub 2012 Jul | ||
1112 | +19. | ||
1113 | + | ||
1114 | +RNAsnap™: a rapid, quantitative and inexpensive, method for isolating total RNA | ||
1115 | +from bacteria. | ||
1116 | + | ||
1117 | +Stead MB(1), Agrawal A, Bowden KE, Nasir R, Mohanty BK, Meagher RB, Kushner SR. | ||
1118 | + | ||
1119 | +Author information: | ||
1120 | +(1)Department of Genetics, University of Georgia, Athens, GA 30602, USA. | ||
1121 | + | ||
1122 | +RNAsnap™ is a simple and novel method that recovers all intracellular RNA | ||
1123 | +quantitatively (>99%), faster (<15 min) and less expensively (∼3 cents/sample) | ||
1124 | +than any of the currently available RNA isolation methods. In fact, none of the | ||
1125 | +bacterial RNA isolation methods, including the commercial kits, are effective in | ||
1126 | +recovering all species of intracellular RNAs (76-5700 nt) with equal efficiency, | ||
1127 | +which can lead to biased results in genome-wide studies involving microarray or | ||
1128 | +RNAseq analysis. The RNAsnap™ procedure yields ∼60 µg of RNA from 10(8) | ||
1129 | +Escherichia coli cells that can be used directly for northern analysis without | ||
1130 | +any further purification. Based on a comparative analysis of specific transcripts | ||
1131 | +ranging in size from 76 to 5700 nt, the RNAsnap™ method provided the most | ||
1132 | +accurate measure of the relative amounts of the various intracellular RNAs. | ||
1133 | +Furthermore, the RNAsnap™ RNA was successfully used in enzymatic reactions such | ||
1134 | +as RNA ligation, reverse transcription, primer extension and reverse | ||
1135 | +transcriptase-polymerase chain reaction, following sodium acetate/ethanol | ||
1136 | +precipitation. The RNAsnap™ method can be used to isolate RNA from a wide range | ||
1137 | +of Gram-negative and Gram-positive bacteria as well as yeast. | ||
1138 | + | ||
1139 | +DOI: 10.1093/nar/gks680 | ||
1140 | +PMCID: PMC3488207 | ||
1141 | +PMID: 22821568 [Indexed for MEDLINE] | ||
1142 | + | ||
1143 | + | ||
1144 | +25. Nucleic Acids Res. 2012 Sep;40(16):7870-84. doi: 10.1093/nar/gks503. Epub 2012 | ||
1145 | +Jun 11. | ||
1146 | + | ||
1147 | +Altered tRNA characteristics and 3' maturation in bacterial symbionts with | ||
1148 | +reduced genomes. | ||
1149 | + | ||
1150 | +Hansen AK(1), Moran NA. | ||
1151 | + | ||
1152 | +Author information: | ||
1153 | +(1)Department of Ecology and Evolutionary Biology, West Campus, Yale University, | ||
1154 | +PO Box 27388 West Haven, CT 06516-7388, USA. allison.hansen@yale.edu | ||
1155 | + | ||
1156 | +Translational efficiency is controlled by tRNAs and other genome-encoded | ||
1157 | +mechanisms. In organelles, translational processes are dramatically altered | ||
1158 | +because of genome shrinkage and horizontal acquisition of gene products. The | ||
1159 | +influence of genome reduction on translation in endosymbionts is largely unknown. | ||
1160 | +Here, we investigate whether divergent lineages of Buchnera aphidicola, the | ||
1161 | +reduced-genome bacterial endosymbiont of aphids, possess altered translational | ||
1162 | +features compared with their free-living relative, Escherichia coli. Our RNAseq | ||
1163 | +data support the hypothesis that translation is less optimal in Buchnera than in | ||
1164 | +E. coli. We observed a specific, convergent, pattern of tRNA loss in Buchnera and | ||
1165 | +other endosymbionts that have undergone genome shrinkage. Furthermore, many | ||
1166 | +modified nucleoside pathways that are important for E. coli translation are lost | ||
1167 | +in Buchnera. Additionally, Buchnera's A + T compositional bias has resulted in | ||
1168 | +reduced tRNA thermostability, and may have altered aminoacyl-tRNA synthetase | ||
1169 | +recognition sites. Buchnera tRNA genes are shorter than those of E. coli, as the | ||
1170 | +majority no longer has a genome-encoded 3' CCA; however, all the expressed, | ||
1171 | +shortened tRNAs undergo 3' CCA maturation. Moreover, expression of tRNA | ||
1172 | +isoacceptors was not correlated with the usage of corresponding codons. Overall, | ||
1173 | +our data suggest that endosymbiont genome evolution alters tRNA characteristics | ||
1174 | +that are known to influence translational efficiency in their free-living | ||
1175 | +relative. | ||
1176 | + | ||
1177 | +DOI: 10.1093/nar/gks503 | ||
1178 | +PMCID: PMC3439896 | ||
1179 | +PMID: 22689638 [Indexed for MEDLINE] | ||
1180 | + |
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