Specifically , RtsA binds to the hilA regulatory gene promoter in SPI-1 while RtsB binds to the flhDC regulatory operon promoter in the flagellar regulon .
RtsA can directly bind the hilA promoter .
a model in which expression of hilA is controlled by the combined action of RtsA
a model in which expression of hilA is controlled by the combined action of RtsA
This is consistent with the feedforward loop model ; when neither RtsA are present , regulation of hilA is dampened , even though the primary signal is mediated through HilD .
Studies have shown PheU that RtsA can each individually bind to the hilA promoter
RtsA , in addition to regulation of hilA , are all capable of inducing expression of the inv/spa operon -- and by the sic/sip operon -- in a fashion independent of HilA .
RtsA , in addition to regulation of hilA , are all capable of inducing expression of the inv/spa operon -- and by read-through -- in a fashion independent of HilA .
This work demonstrates the regulation of hilA by RtsA .
In agreement with genetic data , we show that the purified RtsA protein , like HilD , binds to hilA promoters .
In agreement with genetic data , we show that the purified RtsA protein , like HilC , binds to hilA promoters .
Transcription from the hilA promoter is in turn mainly regulated by three transcription factors ; RtsA .
Model 4 : Two feedforward loops with OR gate model of regulation of PhilA by heterodimers of HilC-HilD , HilC-RtsA and HilD-RtsA In this case functions s3 , s4 and s are m 5-1/4 : ð 1/2 HilD 1/2 HilC ÞH3 kH3 þ ð 1/2 HilD 1/2 HilC ÞH3 3 odified as follows : s 3 s 4 Model 2 : Two feedforward loops with OR gate logic for regulation of P by HilD , HilC and RtsA -LRB- monomer hilA activation -RRB- ðModel 4Þ s 5 In this case , the rate of change of HilA concentration is a additive function of the three input transactivators via the functions s3 , s4 and s5 corresponding to HilD , HilC and RtsA respectively and is represented as : d 1/2 HilA 1/4 1/2 þ 1/2 þ þ b3 b3 s3 s4 s5 s dt Model 3 : Two feedforward loops with OR gate model for regulation of PhilA by monomers of HilD , HilC and RtsA and addition of positive feedback on RtsA and HilC as well as cross activations of RtsA on HilC and vice versa where functions s7 and s9 represent the auto-activation of HilC and RtsA respectively and functions s8 and s10 represent the cross activation of HilC by RtsA and vice versa respectively .
1/4 : ð 1/2 HilD 1/2 RtsA ÞH5 kH5 þ ð 1/2 HilD 1/2 RtsA ÞH5 2 : Two feedforward loops with OR gate for regulation of P by sA ( monomer hilA activ ðModel 4Þ s 5 This corresponds to activation via the heterodimeric complex of lD a with cooperativity H5 and threshold of activation K5 .
1/4 : ð 1/2 HilD 1/2 RtsA ÞH5 kH5 þ ð 1/2 HilD 1/2 RtsA ÞH5 2 : Two feedforward loops with OR gate for regulation of P by sA ( monomer hilA activ ðModel 4Þ s 5 This corresponds to activation via the heterodimeric complex of lex with cooperativity H5 and threshold of activation K5 .
1/4 : ð 1/2 HilD 1/2 RtsA ÞH5 kH5 þ ð 1/2 HilD 1/2 RtsA ÞH5 ÞH5 5 Mo for regulation of P by sA ( monomer hilA activ ðModel 4Þ s 5 This corresponds to activation via the heterodimeric complex of lD a with cooperativity H5 and threshold of activation K5 .
1/4 : ð 1/2 HilD 1/2 RtsA ÞH5 kH5 þ ð 1/2 HilD 1/2 RtsA ÞH5 ÞH5 5 Mo for regulation of P by sA ( monomer hilA activ ðModel 4Þ s 5 This corresponds to activation via the heterodimeric complex of lex with cooperativity H5 and threshold of activation K5 .
Earlier work on mathematical modeling of regulation of expression of hilA by RtsA was based on feed-forward architecture , considering HilD to be the primary activator of the feed-forward loop .
Differential expression of hilA , is influenced by RtsA
LoiA activates expression of hilA gene through activating hilD As the expression of hilA is directly controlled by RtsA , we tested whether LoiA regulates HilA through any of these three regulators .