Vibrio parahaemolyticus ScrC modulates cyclic dimeric GMP regulation of gene expression relevant to growth on surfaces.
In Vibrio parahaemolyticus, scrC participates in controlling the decision to be a highly mobile swarmer cell or a more adhesive, biofilm-proficient cell type. scrC mutants display decreased swarming motility over surfaces and enhanced capsular polysaccharide production. ScrC is a cytoplasmic membrane protein that contains both GGDEF and EAL conserved protein domains. These domains have been shown in many organisms to respectively control the formation and degradation of the small signaling nucleotide cyclic dimeric GMP (c-di-GMP). The scrC gene is part of the three-gene scrABC operon. Here we report that this operon influences the cellular nucleotide pool and that c-di-GMP levels inversely modulate lateral flagellar and capsular polysaccharide gene expression. High concentrations of this nucleotide prevent swarming and promote adhesiveness. Further, we demonstrate that ScrC has intrinsic diguanylate cyclase and phosphodiesterase activities, and these activities are controlled by ScrAB. Specifically, ScrC acts to form c-di-GMP in the absence of ScrA and ScrB; whereas ScrC acts to degrade c-di-GMP in the presence of ScrA and ScrB. The scrABC operon is specifically induced by growth on a surface, and the analysis of mutant phenotypes supports a model in which the phosphodiesterase activity of ScrC plays a dominant role during surface translocation and in biofilms.
Ferreira
Rosana B R
RB
Department of Microbiology, The University of Iowa, Iowa City, Iowa 52242, USA.
Antunes
Luis Caetano M
LC
Greenberg
E Peter
EP
McCarter
Linda L
LL
D001422:Bacterial Adhesion; D016667:Bacterial Capsules / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006152:Cyclic GMP / Q000378:metabolism / Q000494:pharmacology*; D019281:Dimerization; D029968:Escherichia coli Proteins; D005407:Flagella / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009876:Operon; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D019761:Phosphorus-Oxygen Lyases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014736:Vibrio parahaemolyticus / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D010727:Phosphoric Diester Hydrolases; D019761:Phosphorus-Oxygen Lyases; C060720:diguanylate cyclase; D006152:Cyclic GMP