A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilD have independent effects on expression of sipC in S. typhimurium .
A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilD have independent effects on expression of sipA in S. typhimurium .
A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilD have independent effects on expression of invF in S. typhimurium .
A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilA have independent effects on expression of sipC in S. typhimurium .
A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilA have independent effects on expression of sipA in S. typhimurium .
A subset of SPI1 genes is induced by HilD overexpression in the absence of hilA Our results suggested that HilA have independent effects on expression of invF in S. typhimurium .
These data demonstrate that HilD can activate a subset of SPI1 genes in the absence of hilA .
the key regulator hilA , we have focused on two activators of HilD .
HilD can independently activate the hilA promoter .
However , evidence from our laboratory indicates that HilD is a required activator of hilA expression necessary for recruitment of RNA polymerase at the hilA promoter .
However , evidence from our laboratory indicates that HilD is a required activator of hilA expression necessary for contact of RNA polymerase at the hilA promoter .
We wanted to determine if HilD could induce expression of hilA in the absence of the other regulators .
The data in Fig. 2 demonstrate that HilD are able to induce expression of hilA in the absence of the other regulators .
Production of HilC induced expression of hilA ~ 120-fold , while HilD induced expression of hilA 30-to 40-fold , similar to previously reported values .
We show that HilD can each independently activate expression of the hilA genes .
However , HilD normally act in concert to activate hilA .
However , our most striking results show that even though HilD appears to be the best hilA activator of the three in-vitro , when working alone it can not induce hilA enough to stimulate invasion .
Olekhnovich , I.N. , and Kadner , R.J. Contribution of the RpoA C-terminal domain to stimulation of the Salmo-nella enterica hilA promoter by HilD .
Olekhnovich , I.N. , and Kadner , R.J. Contribution of the RpoA C-terminal domain to stimulation of the Salmo-nella enterica hilA promoter by HilD .
HilD can activate expression of hilA .
Contribution of the RpoA C-terminal domain to stimulation of the Salmonella enterica hilA promoter by HilD .
Contribution of the RpoA C-terminal domain to stimulation of the Salmonella enterica hilA promoter by HilD .
Since HilD activates hilA transcription , it was surprising that reduced transcription of the central regulator HilA was not detected by microarray analysis .
The mechanism by which HilD activate expression of hilA
That means that at least hilA are induced by HilD .
To test whether HilD activators of hilA are also regulated by these proteins , we investigated the transcription of hilD-lac chromosomal fusions .
To test whether HilD activators of hilA are also regulated by these proteins , we investigated the transcription of hilC-lac .
To test whether HilD activators of hilA are also regulated by these proteins , we investigated the transcription of rtsA-lac .
Under high-osmolarity conditions , HilD activate SPI1 genes indirectly through hilA .
Under high-osmolarity conditions , HilD activate SPI1 genes directly through hilA .
Contribution of the RpoA C-terminal domain to stimulation of the Salmonella enterica hilA promoter by HilD .
Contribution of the RpoA C-terminal domain to stimulation of the Salmonella enterica hilA promoter by HilD .
HilD are each capable of activating hilA transcription .
HilD induces expression of the hilA gene by derepressing the silencing effect of Hha on the hilA promoter
HilD induces expression of the hilA gene by derepressing the silencing effect of H-NS on the hilA promoter
Earlier work on mathematical modeling of regulation of expression of hilA by HilD was based on feed-forward architecture , considering HilD to be the primary activator of the feed-forward loop .
Both HilC and HilD activate expression of SPI-1 genes by binding upstream of the master regulatory gene hilA to induce its expression .
HilD are central activators of hilA expression ( Ellermeier et al. , 2005 ; 2001 ; Schechter et al. , Abbreviations : Cy , Cyanine ; SSC , saline sodium citrate ; SPI1 , Salmonella pathogenicity island 1 ; S. Typhimurium , Salmonella enterica serovar Typhimurium ; TTSS , type III secretion system .
HilD are central activators of hilA expression ( Ellermeier et al. , 2005 ; Lee ; Schechter et al. , Abbreviations : Cy , Cyanine ; SSC , saline sodium citrate ; SPI1 , Salmonella pathogenicity island 1 ; S. Typhimurium , Salmonella enterica serovar Typhimurium ; TTSS , type III secretion system .
HilD are central activators of hilA expression ( Ellermeier et al. , 2005 ; Lucas ; Schechter et al. , Abbreviations : Cy , Cyanine ; SSC , saline sodium citrate ; SPI1 , Salmonella pathogenicity island 1 ; S. Typhimurium , Salmonella enterica serovar Typhimurium ; TTSS , type III secretion system .
The AraC-like transcriptional regulator HilD , positively regulates the expression of the SPI-1 genes in a cascade fashion , mainly by directly inducing the expression of hilA .
Several studies strongly support the idea that HilD induces the expression of hilA by counteracting the repression .
hilA expression is induced by three transcriptional activators , HilD .
Transcription of hilA is directly activated by HilD .
HilD positively regulates hilA
Previous studies indicate that HilD induces the expression of hilA by counteracting the repression hilA can be expressed independently of HilD .
HilD is the key activator of hilA transcription
HilD , activate directly the expression of hilA , independently of HilA .
HilD , induces the expression of hilA .
Altogether , these results suggest that HilD plays a pivotal role in activating hilA expression under the experimental conditions .
It was found that LoiA positively regulates the expression of hilA -LRB- the master activator of SPI-1 -RRB- through direct activation of HilD under low O2 conditions , leading to the activation of SPI-1 genes for invasion .
HilD in turn activates hilA expression
Briefly , ArcB responds to low oxygen conditions when bacteria undergoes autophosphorylation , following which the phosphate group is transferred to ArcA ; phosphorylated ArcA-P activates loiA gene expression indirectly through unknown regulator ; LoiA activates HilD directly through binding the hilD promoter ; HilD then activates hilA SPI-1 genes .
Briefly , ArcB responds to low oxygen conditions when bacteria undergoes autophosphorylation , following which the phosphate group is transferred to ArcA ; phosphorylated ArcA activates loiA gene expression indirectly through unknown regulator ; LoiA activates HilD directly through binding the hilD promoter ; HilD then activates hilA SPI-1 genes .
Briefly , ArcB responds to low oxygen conditions when bacteria reach the distal ileum ; phosphorylated ArcA-P activates loiA gene expression indirectly through unknown regulator ; LoiA activates HilD directly through binding the hilD promoter ; HilD then activates hilA SPI-1 genes .
Briefly , ArcB responds to low oxygen conditions when bacteria reach the distal ileum ; phosphorylated ArcA activates loiA gene expression indirectly through unknown regulator ; LoiA activates HilD directly through binding the hilD promoter ; HilD then activates hilA SPI-1 genes .
Transcription of the hilA gene is also stimulated by HilD .