• The gene rpoS (RNA polymerase, sigma S, also called katF) encodes the sigma factor sigma-38 (σ38, or RpoS), a 37.8 kD protein in Escherichia coli. (wikipedia.org)
  • RpoS proteolysis forms another level of the sigma factor's regulation. (wikipedia.org)
  • Here we show that DnaK increases the expression of CsgA and CsgB-the major and minor structural components of curli, respectively-via a quantity and quality control of RpoS, a stationary phase-specific alternative sigma factor regulating bacterial transcription, and CsgD, the master transcriptional regulator of curli formation. (nature.com)
  • Regulation of the N -acyl homoserine lactone-dependent quorum-sensing system in rhizosphere Pseudomonas putida WCS358 and cross-talk with the stationary-phase RpoS sigma factor and the global regulator GacA. (microbiologyresearch.org)
  • Poly P is involved in the expression in E. coli of RpoS (9), the sigma factor responsible for activation of more than 50 genes required for survival during starvation, UV radiation, oxidative damage, and osmotic stress (10, 11). (nih.gov)
  • This is exemplified in the regulation of RpoS, a stress sigma factor of E. coli . (nih.gov)
  • The small regulatory protein Crl favors association of the stationary-phase sigma factor sigma(S) (RpoS) with the core enzyme polymerase and thereby increases sigma(S) activity. (pasteur.fr)
  • In addition, our results revealed that sigma(S) exerts a negative effect on the production of Crl in stationary phase when the cells contain high levels of sigma(S). (pasteur.fr)
  • rpoS is transcribed in late exponential phase, and RpoS is the primary regulator of stationary phase genes. (wikipedia.org)
  • Evidence that infective S. flexneri is in a stationary, nondividing state and that expression of stationary- phase-specific genes is essential for survival and virulence pro- vides support for a role for poly P in its pathogenesis. (nih.gov)
  • Since rpoS is a central element in a regulatory network that governs the expression of stationary-phase-induced genes, poly(P) affects the expression of many genes through controlling rpoS expression. (msu.ru)
  • Furthermore, poly(P) is also involved in expression of other stress-inducible genes that are not directly regulated by rpoS . (msu.ru)
  • We found 245 genes at the exponential growth phase and 273 genes at the early stationary phase to be ≥ 1.5-fold differentially expressed. (biomedcentral.com)
  • As the most striking result during stationary phase, however, we obtained in the 6S RNA deficient strain a concerted expression reduction of genes constituting the translational apparatus. (biomedcentral.com)
  • and 3) vs., which controls the stationary phase of growth and the expression of genes that are critical to the pathogenesis of Lyme disease. (nih.gov)
  • The rpoS gene most likely originated in the gammaproteobacteria. (wikipedia.org)
  • Regulatory mechanisms that control RpoS exist at various levels of gene and protein organization: transcription, translation, degradation, and protein activity. (wikipedia.org)
  • Control of RpoS in global gene expression of Escherichia coli in minimal media. (microbiologyresearch.org)
  • In view of the phylogenetic similarity of the enteropathogens and the frequency with which virulence factors are expressed in stationary phase, the ppk gene of pathogenic Shigella flexneri, Salmonella enterica serovar Dublin, and Salmonella enterica serovar typhi- murium have been cloned and deleted. (nih.gov)
  • these can all be linked to a decreased expression of the rpoS gene (9). (nih.gov)
  • Transcription of rpoS in E. coli is mainly regulated by the chromosomal rpoSp promoter. (wikipedia.org)
  • RpoS translation was also shown to be controlled in other bacterial species, beside Escherichia coli. (wikipedia.org)
  • Escherichia coli mutants lacking polyphosphate kinase (PPK), the enzyme responsible for the syn- thesis of poly P from ATP, are deficient in responses to stresses and stringencies and fail to survive in stationary phase (3, 4). (nih.gov)
  • coli (9) can be added to the similarity of S. flexneri in the expressions of several invasion operons (¢.g., viz, ipa, mxi, and spa) that are maximal in stationary-phase cultures (13, 14). (nih.gov)
  • Our experiments sought to define more precisely the roles of pH, fermentation acids, redox potential and RpoS in the acid resistance in E. coli O157:H7. (usda.gov)
  • The growth conditions of Escherichia coli O157:H7 greatly affected its ability to survive a subsequent acid shock (pH 2.0, 6 h, 37s C). When cultures were grown anaerobically with increasing amounts of glucose, acetate accumulated, and extracellular pH declined from 7.4 to 4.7, and the viable count of stationary phase cells after acid shock increased 1000-fold. (usda.gov)
  • An rpoS mutant of E. coli O157:H7 was always more sensitive to acid shock than wild-type, and large amounts of acetate were needed to promote even small increases in viability. (usda.gov)
  • sRNAs (small noncoding RNAs) sense environmental changes and in turn increase rpoS mRNA translation to allow the cell to accordingly adjust to external stress. (wikipedia.org)
  • In addition to this complex regulation of RpoS degradation, the translation of RpoS is positively regulated by multiple small RNAs. (nih.gov)
  • The small RNAs link RpoS regulation to multiple environmental and metabolic inputs. (nih.gov)
  • During late stationary phase most of the Eσ 70 RNA polymerase is considered to be bound to 6S RNA and thus should generally be prevented from binding to σ 70 -dependent promoters. (biomedcentral.com)
  • While many key regulatory entities have been identified in these areas, the precise mechanisms by which they signal rpoS transcription, translation, proteolysis or activity remain largely uncharacterized. (wikipedia.org)
  • rpoSp promotes transcription of rpoS mRNA, and is induced upon entry into stationary phase in cells growing on rich media via an unknown mechanism. (wikipedia.org)
  • Flanking rpoSp are two putative cAMP-CRP (cyclic AMP-cAMP receptor protein) binding sites that seem to control rpoS transcription in an antagonistic manner. (wikipedia.org)
  • In exponential phase, crp mutants exhibit high levels of rpoS expression, suggesting that cAMP-CRP inhibits rpoS transcription. (wikipedia.org)
  • Upon entry into stationary phase, on the other hand, cAMP-CRP may upregulate rpoS transcription (Hengge-Aronis, 2002). (wikipedia.org)
  • 1993). Despite the numerous controls on rpoS transcription, cellular rpoS mRNA levels remain high during exponential phase and the majority of extracellular stimuli do not significantly affect rpoS transcription. (wikipedia.org)
  • The promoter of the 85 nucleotide sRNA DsrA contains a temperature-sensitive transcription initiation thermocontrol as it is repressed at high (42˚C) temperatures, but induces (perhaps by complementary binding to) rpoS at low (25˚C) temperatures. (wikipedia.org)
  • We show that transcription from the wild-type and the activated bgl promoter exhibits a growth phase-dependent enhancement that is highest in the stationary phase. (iisc.ac.in)
  • Our studies also indicate that while BglJ has a moderate effect on the expression of the bgl operon in the stationary phase in the absence of rpoS/crl, the modest increase in LeuO concentration in the stationary phase is insufficient to affect transcription from the bgl promoter. (iisc.ac.in)
  • Because 6S RNA concentrations are maximal at stationary phase and binding occurs preferentially to the holoenzyme associated with σ 70 (Eσ 70 ) it is believed that 6S RNA supports adjustment to stationary phase transcription. (biomedcentral.com)
  • In contrast, LeuO inhibits rpoS translation by repressing dsrA expression and the histone-like protein HN-S (and its paralog StpA) inhibits rpoS translation via an unknown mechanism. (wikipedia.org)
  • In addition, H-NS, LeuO, Hfq and DsrA form an interconnected regulatory network that ultimately controls rpoS translation. (wikipedia.org)
  • We have assessed the effect of mutations in rpoS, crl, hns, leuO and bglJ, known to regulate bgl expression, on the growth phase-dependent increase in bgl activity. (iisc.ac.in)
  • Furthermore, phzR but not rpoS was able to complement the phzRrpoS double mutant for the aforementioned traits, indicating that the Phz QS system is a central regulator of PA23-mediated antagonism. (microbiologyresearch.org)
  • While both QS-deficient strains produced little biofilm, the rpoS mutant showed enhanced biofilm production compared with PA23. (microbiologyresearch.org)
  • To identify pathways controlled by CsrA, RNA-seq transcriptome analysis was carried out by comparing the wild type and the csrA mutant grown to early exponential, mid-exponential, and stationary phases of growth. (utexas.edu)
  • RpoS is a central regulator of the general stress response and operates in both a retroactive and a proactive manner: it not only allows the cell to survive environmental challenges, but it also prepares the cell for subsequent stresses (cross-protection). (wikipedia.org)
  • A second small RNA regulator of RpoS, RprA, was also identified. (nih.gov)
  • We identified a third small RNA regulator of RpoS, ArcZ, that also positively regulates RpoS but is controlled by regulators that sense aerobic vs. anaerobic growth. (nih.gov)
  • RpoS is rapidly degraded during exponential growth by the ClpXP protease but not when the cell is starved, stressed, or enters stationary phase. (nih.gov)
  • One of these, DsrA, is synthesized preferentially at low temperatures and is necessary for the low-temperature expression of RpoS. (nih.gov)
  • DsrA modulates RpoS synthesis by positively affecting translation of this protein by pairing with parts of the RpoS untranslated leader. (nih.gov)
  • RprA acts by a mechanism similar to that of DsrA in stimulating RpoS synthesis, but is regulated not by low temperature but by a two-component regulatory system responsive to cell surface status. (nih.gov)
  • Another sRNA, RprA, stimulates rpoS translation in response to cell surface stress signaled via the RcsC sensor kinase. (wikipedia.org)
  • Analysis of transcriptional fusions revealed that RpoS has a positive and negative effect on phzI and phzR , respectively. (microbiologyresearch.org)
  • To solve this apparent ambiguity and to better understand the role of 6S RNA in stationary phase transition we have performed a genome-wide transcriptional analysis of wild-type and 6S RNA deficient cells growing to mid-log or early stationary phase. (biomedcentral.com)
  • Finally, we discovered that QS and RpoS have opposing effects on PA23 biofilm formation. (microbiologyresearch.org)
  • Collectively, our findings indicate that QS controls diverse aspects of PA23 physiology, including secondary metabolism, RpoS and biofilm formation. (microbiologyresearch.org)
  • At the next stage (3), the first maturation phase is reached, as indicated by early development of biofilm architecture. (biomedcentral.com)
  • The second maturation phase is reached at stage 4 with fully mature biofilms, as indicated by the complex biofilm architecture. (biomedcentral.com)
  • Eighteen listeners were presented with free-field sound stimuli that, after an initial stationary phase at a lateral spatial position within the left or right hemifield, started to move either left- or rightward. (cdk-receptor.com)
  • As the majority of secondary metabolites are produced at the onset of stationary phase, we investigated whether cross-regulation occurs between QS and RpoS. (microbiologyresearch.org)
  • RssB, an adaptor protein for RpoS degradation, affects degradation only of RpoS, and not of other ClpXP substrates, in vivo and in vitro . (nih.gov)
  • Most RpoS expression is determined at the translational level. (wikipedia.org)
  • Measurements of the fitness of strains carrying the wild type or a null allele of crl showed that, while the strain deleted for crl exhibited a growth advantage over the crl(+) strain in an rpoS(+) background, it showed a low-level disadvantage in the presence of an rpoS allele that results in attenuated RpoS expression. (iisc.ac.in)
  • Sensitivity to H 2 O 2 and heat shock evinced by cells that overproduce PPX1 is attributed to depressed levels of rpoS expression. (msu.ru)
  • When cultures were grown with a low concentration of glucose (2 mM) at pH values ranging from 7.0 to 5.6, the extracellular acetate concentration was always 3 mM, but viable count of stationary phase cells after acid shock increased 1000-fold. (usda.gov)
  • The mechanism by which OxyS interferes with rpoS mRNA translational efficiency is not known. (wikipedia.org)
  • With microarray technologies, scientists are forming global views of the structural and dynamic changes in genome activity during different phases in a cell's development and following exposure to external stimulants such as environmental agents or growth factors. (nih.gov)
  • Using a genetic screen, we identified multiple small anti-adaptor proteins that are made in response to specific stress signals and interfere with the ability of RssB to deliver RpoS to the protease. (nih.gov)
  • These studies show that this increase is greater in the absence of wild-type rpoS and/or crl. (iisc.ac.in)
  • The primary question has been how environmental signals regulate RpoS degradation. (nih.gov)