A two-component phosphotransfer network involving ArcB, ArcA, and RssB coordinates synthesis and proteolysis of σS (RpoS) in E. coli
| Autor: | Franziska Mika, Regine Hengge |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Transcription
Genetic Repressor Sigma Factor Biology chemistry.chemical_compound Bacterial Proteins Sigma factor Transcription (biology) RNA polymerase Escherichia coli Genetics Phosphorylation Transcription factor Escherichia coli Proteins Hydrolysis Phosphotransferases Autophosphorylation Membrane Proteins Gene Expression Regulation Bacterial Research Papers DNA-Binding Proteins Repressor Proteins Response regulator chemistry Biochemistry Mutation bacteria Protein Kinases rpoS Bacterial Outer Membrane Proteins Transcription Factors Developmental Biology |
| Zdroj: | Genes & Development. 19:2770-2781 |
| ISSN: | 1549-5477 0890-9369 |
| DOI: | 10.1101/gad.353705 |
| Popis: | The general stress σ factor σS (RpoS) in Escherichia coli is controlled at the levels of transcription, translation, and proteolysis. Here we demonstrate that the phosphorylated response regulator ArcA is a direct repressor of rpoS transcription that binds to two sites flanking the major rpoS promoter, with the upstream site overlapping an activating cAMP-CRP-binding site. The histidine sensor kinase ArcB not only phosphorylates ArcA, but also the σS proteolytic targeting factor RssB, and thereby stimulates σS proteolysis. Thus, ArcB/ArcA/RssB constitute a branched “three-component system”, which coordinates rpoS transcription and σS proteolysis and thereby maintains low σS levels in rapidly growing cells. We suggest that the redox state of the quinones, which controls autophosphorylation of ArcB, not only monitors oxygen but also energy supply, and we show that the ArcB/ArcA/RssB system is involved in σS induction during entry into starvation conditions. Moreover, this induction is enhanced by a positive feedback that involves σS-dependent induction of ArcA, which further reduces σS proteolysis, probably by competing with RssB for residual phosphorylation by ArcB. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|