[ODP-059] Regulation of sRNA1 expression by ArcA in Vibrio alginolyticus
Two-component regulatory system enable bacteria to sense, respond, and adapt to changes in their environment. VarS/VarA system controls the expression of target genes via regulating the transcription of multiple small RNAs (sRNAs). We revealed that, in Vibrio alginolyticus, VarS/VarA system controls transcription of four sRNAs (sRNA1, 2, 3, and 4). Previous studies suggested that other regulators control the expression of sRNAs. To identify the regulators that control the expression of sRNAs, proteins that bind to the sRNA promoter region were pulled down from the cell lysate. Several protein bands that were specifically pulled-down with each sRNA promoter were identified. Using mass spectrometry, one that was pulled-down with sRNA1 promoter was expected to be ArcA, a response regulator of ArcA/ArcB system that mediates adaptation to anaerobic growth conditions. Electromobility shift assay with recombinant ArcA confirmed that ArcA bound to the predicted ArcA binding site on the sRNA1 promoter region, but not to other sRNA promoters. Deletion of arcA decreased the amount of sRNA1 when cells were grown under anaerobic condition, but had no effect under aerobic condition. These results demonstrate that expression of sRNA1 is also regulated by the ArcA/ArcB system. It seems likely that expressions of VarS/VarA-controlled sRNAs were controlled by multiple environmental signals.