Title |
MINIREVIEW] Two stress sensor proteins for the expression of sigmaE regulon: DegS and RseB |
Author |
Dong Young Kim* |
Address |
College of Pharmacy, Yeungnam University, Gyeongsan 712-749, Republic of Korea |
Bibliography |
Journal of Microbiology, 53(5),306-310, 2015,
|
DOI |
10.1007/s12275-015-5112-6
|
Key Words |
sigmaE, RseA, RseB, DegS, OMP, LPS |
Abstract |
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. |