Two-Component System Response Regulator <i>ompR</i> Regulates Mussel Settlement through Exopolysaccharides

Abstract

The outer membrane protein (OMP) is a kind of biofilm matrix component that widely exists in Gram-negative bacteria. However, the mechanism of OMP involved in the settlement of molluscs is still unclear. In this study, the mussel Mytilus coruscus was selected as a model to explore the function of ompR, a two-component system response regulator, on Pseudoalteromonas marina biofilm-forming capacity and the mussel settlement. The motility of the ΔompR strain was increased, the biofilm-forming capacity was decreased, and the inducing activity of the ΔompR biofilms in plantigrades decreased significantly (p ompR strain decreased by 57.27% and 62.63%, respectively. The inactivation of the ompR gene decreased the ompW gene expression and had no impact on envZ expression or c-di-GMP levels. Adding recombinant OmpW protein caused the recovery of biofilm-inducing activities, accompanied by the upregulation of exopolysaccharides. The findings deepen the understanding of the regulatory mechanism of bacterial two-component systems and the settlement of benthic animals.

Keywords

• <i>Pseudoalteromonas marina</i>
• <i>ompR</i> gene
• OmpW
• biofilm
• <i>Mytilus coruscus</i>
• settlement