Two stress sensor proteins for the expression of sigmaE regulon: DegS and RseB

• Published in: The journal of microbiology Vol. 53; no. 5; pp. 306 - 310
• Main Author: Kim, Dong Young
• Format: Journal Article
• Language: English
• Published: Seoul Springer-Verlag 01.05.2015; The Microbiological Society of Korea; Springer Nature B.V; 한국미생물학회
• Subjects: Bacterial Outer Membrane Proteins - genetics; Bacterial Outer Membrane Proteins - metabolism; biogenesis; Biomedical and Life Sciences; Biosynthesis; Cytoplasm; E coli; Endopeptidases - metabolism; Escherichia coli; Escherichia coli - genetics; Escherichia coli Proteins - genetics; Escherichia coli Proteins - metabolism; Gene Expression Regulation, Bacterial; Homeostasis; Life Sciences; Membrane Proteins - genetics; Membrane Proteins - metabolism; Microbiology; Minireview; Periplasm - metabolism; proteinases; Proteins; proteolysis; Regulon; RNA polymerase; Sensors; Sigma Factor - genetics; Signal Transduction; Stress, Physiological; Transcription Factors - genetics; 생물학; RseB; RseA; OMP; sigmaE; DegS; LPSs
• ISSN: 1225-8873; 1976-3794; 1976-3794
• DOI: 10.1007/s12275-015-5112-6

In E. coli, sigmaE-dependent transcription is controlled by regulated-proteolysis of RseA. RseA, which holds sigmaE as an anti-sigma factor, is sequentially digested by DegS, RseP and cytoplasmic proteases to liberate sigmaE in response to dysfunction in outer-membrane biogenesis. Additionally, the sequential proteolysis is regulated by RseB binding to RseA (Fig. 1A). Direct interaction between RseA and RseB inhibits RseA-cleavage by DegS. Both proteolytic activation of DegS and binding disruption of RseB are thus required to initiate sigmaE-stress response. For the induction of sigmaEstress response, DegS and RseB recognize the states of OMP and LPS for outer-membrane biogenesis. DegS is activated by binding of unfolded OMPs and RseB binding to RseA is antagonized by LPS accumulated in periplasm. In this regard, DegS and RseB are proposed to be stress sensor proteins for sigmaE signal transduction. Interestingly, biogenesis of OMP and LPS appears to cross-talk with each other, indicating that dysfunction of either OMP or LPS can initiate RseA proteolysis. This review aims to briefly introduce two stress sensor proteins, DegS and RseB, which regulate sigmaEdependent transcription.