AUTHOR=Ren Gai-Xian , Guo Xiao-Peng , Sun Yi-Cheng 

TITLE=HmsC Controls Yersinia pestis Biofilm Formation in Response to Redox Environment

JOURNAL=Frontiers in Cellular and Infection Microbiology

VOLUME=7

YEAR=2017

URL=https://www.frontiersin.org/journals/cellular-and-infection-microbiology/articles/10.3389/fcimb.2017.00355

DOI=10.3389/fcimb.2017.00355

ISSN=2235-2988

ABSTRACT=<p><italic>Yersinia pestis</italic> biofilm formation, controlled by intracellular levels of the second messenger molecule cyclic diguanylate (c-di-GMP), is important for blockage-dependent plague transmission from fleas to mammals. HmsCDE is a tripartite signaling system that modulates intracellular c-di-GMP levels to regulate biofilm formation in <italic>Y. pestis</italic>. Previously, we found that <italic>Y. pestis</italic> biofilm formation is stimulated in reducing environments in an <italic>hmsCDE</italic>-dependent manner. However, the mechanism by which HmsCDE senses the redox state remains elusive. Using a <italic>dsbA</italic> mutant and the addition of Cu<sup>2+</sup> to simulate reducing and oxidizing periplasmic environments, we found that HmsC protein levels are decreased and the HmsC-HmsD protein-protein interaction is weakened in a reducing environment. In addition, we revealed that intraprotein disulphide bonds are critical for HmsC since breakage lowers protein stability and diminishes the interaction with HmsD. Our results suggest that HmsC might play a major role in sensing the environmental changes.</p>