UNDER A-SALT: Investigating the role of CosR in Osmotic Stress Response Of Vibrio parahaemolyticus
Date
2019-05
Authors
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Journal ISSN
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Publisher
University of Delaware
Abstract
The marine bacterium Vibrio parahaemolyticus has evolved multiple strategies
for adapting to short- and long-term shifts in osmolarity. One such mechanism
involves the uptake and/or biosynthesis of small organic molecules known as
compatible solutes. These compatible solutes act to balance the osmolarity of the cell
without disrupting important biological processes. V. parahaemolyticus is able to
uptake compatible solutes through six transport systems: two ABC type transporters
named ProU1 and ProU2 and four betaine carnitine choline transporters (BCCTs).
Additionally, V. parahaemolyticus can biosynthesize glycine betaine and ectoine.
Ectoine gene expression was previously shown to be regulated by a MarR-type
regulator CosR in V. cholerae. In this study, we identify a CosR homologue (VP1906)
present in all strains of V. parahaemolyticus and characterize its role in the osmotic
stress response through the generation of a cosR deletion strain. Through quantitative
Real-Time PCR (qPCR), we demonstrate that CosR plays a role in regulation of the
ectoine biosynthesis genes as well as bcct1 (VP0456) and bcct3 (VP1905).
Additionally, we show that CosR is able to bind to the promoter regions of these
operons, as well as directly repress transcription of the ectABCaspK operon in vitro.
Taken together, these data suggest that CosR is an important global regulator in the
osmotic stress response of V. parahaemolyticus.
Description
Keywords
CosR, Vibrio parahaemolyticus