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RpoS synthesis is growth rate regulated in Salmonella typhimurium, but its turnover is not dependent on acetyl phosphate synthesis or PTS function.
J Bacteriol. 1999 Aug; 181(16):4853-62.JB

Abstract

The RpoS sigma factor of enteric bacteria is either required for or augments the expression of a number of genes that are induced during nutrient limitation, growth into stationary phase, or in response to stresses, including high osmolarity. RpoS is regulated at multiple levels, including posttranscriptional control of its synthesis, protein turnover, and mechanisms that affect its activity directly. Here, the control of RpoS stability was investigated in Salmonella typhimurium by the isolation of a number of mutants specifically defective in RpoS turnover. These included 20 mutants defective in mviA, the ortholog of Escherichia coli rssB/sprE, and 13 mutants defective in either clpP or clpX which encode the protease active on RpoS. An hns mutant was also defective in RpoS turnover, thus confirming that S. typhimurium and E. coli have identical genetic requirements for this process. Some current models predict the existence of a kinase to phosphorylate the response regulator MviA, but no mutants affecting a kinase were recovered. An mviA mutant carrying the D58N substitution altering the predicted phosphorylation site is substantially defective, suggesting that phosphorylation of MviA on D58 is important for its function. No evidence was obtained to support models in which acetyl phosphate or the PTS system contributes to MviA phosphorylation. However, we did find a significant (fivefold) elevation of RpoS during exponential growth on acetate as the carbon and energy source. This behavior is due to growth rate-dependent regulation which increases RpoS synthesis at slower growth rates. Growth rate regulation operates at the level of RpoS synthesis and is mainly posttranscriptional but, surprisingly, is independent of hfq function.

Authors+Show Affiliations

Department of Microbiology and Immunology, West Virginia University Health Sciences Center, Morgantown, West Virginia 26506, USA.No affiliation info available

Pub Type(s)

Journal Article
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

10438755

Citation

Cunning, C, and T Elliott. "RpoS Synthesis Is Growth Rate Regulated in Salmonella Typhimurium, but Its Turnover Is Not Dependent On Acetyl Phosphate Synthesis or PTS Function." Journal of Bacteriology, vol. 181, no. 16, 1999, pp. 4853-62.
Cunning C, Elliott T. RpoS synthesis is growth rate regulated in Salmonella typhimurium, but its turnover is not dependent on acetyl phosphate synthesis or PTS function. J Bacteriol. 1999;181(16):4853-62.
Cunning, C., & Elliott, T. (1999). RpoS synthesis is growth rate regulated in Salmonella typhimurium, but its turnover is not dependent on acetyl phosphate synthesis or PTS function. Journal of Bacteriology, 181(16), 4853-62.
Cunning C, Elliott T. RpoS Synthesis Is Growth Rate Regulated in Salmonella Typhimurium, but Its Turnover Is Not Dependent On Acetyl Phosphate Synthesis or PTS Function. J Bacteriol. 1999;181(16):4853-62. PubMed PMID: 10438755.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - RpoS synthesis is growth rate regulated in Salmonella typhimurium, but its turnover is not dependent on acetyl phosphate synthesis or PTS function. AU - Cunning,C, AU - Elliott,T, PY - 1999/8/10/pubmed PY - 1999/8/10/medline PY - 1999/8/10/entrez SP - 4853 EP - 62 JF - Journal of bacteriology JO - J Bacteriol VL - 181 IS - 16 N2 - The RpoS sigma factor of enteric bacteria is either required for or augments the expression of a number of genes that are induced during nutrient limitation, growth into stationary phase, or in response to stresses, including high osmolarity. RpoS is regulated at multiple levels, including posttranscriptional control of its synthesis, protein turnover, and mechanisms that affect its activity directly. Here, the control of RpoS stability was investigated in Salmonella typhimurium by the isolation of a number of mutants specifically defective in RpoS turnover. These included 20 mutants defective in mviA, the ortholog of Escherichia coli rssB/sprE, and 13 mutants defective in either clpP or clpX which encode the protease active on RpoS. An hns mutant was also defective in RpoS turnover, thus confirming that S. typhimurium and E. coli have identical genetic requirements for this process. Some current models predict the existence of a kinase to phosphorylate the response regulator MviA, but no mutants affecting a kinase were recovered. An mviA mutant carrying the D58N substitution altering the predicted phosphorylation site is substantially defective, suggesting that phosphorylation of MviA on D58 is important for its function. No evidence was obtained to support models in which acetyl phosphate or the PTS system contributes to MviA phosphorylation. However, we did find a significant (fivefold) elevation of RpoS during exponential growth on acetate as the carbon and energy source. This behavior is due to growth rate-dependent regulation which increases RpoS synthesis at slower growth rates. Growth rate regulation operates at the level of RpoS synthesis and is mainly posttranscriptional but, surprisingly, is independent of hfq function. SN - 0021-9193 UR - https://www.unboundmedicine.com/medline/citation/10438755/RpoS_synthesis_is_growth_rate_regulated_in_Salmonella_typhimurium_but_its_turnover_is_not_dependent_on_acetyl_phosphate_synthesis_or_PTS_function_ L2 - http://jb.asm.org/cgi/pmidlookup?view=long&pmid=10438755 DB - PRIME DP - Unbound Medicine ER -