The carbon starvation stimulon in the marine Vibrio sp. S14 (CCUG 15956) includes three periplasmic space protein responders

Abstract

Summary: Growth arrest and long-term starvation in the marine Vibrio sp. S14 induce alterations of the cell envelope as well as a sequential expression of starvation-specific polypeptides. The induction and accumulation of three dominant carbon-starvation-induced periplasmic space protein responders of molecular mass 120 (Cspl), 37 (Csp5) and 30 kDa (Csp6), were examined under different starvation and stress conditions. All three proteins were increasingly synthesized in response to carbon and multiple-nutrient starvation, but not during nitrogen and phosphorus starvation, nor in response to the imposition of stress conditions. Csp1 exhibited a more than 100-fold increased relative induction by carbon and multiple-nutrient starvation and was continuously synthesized throughout the experiment. Induction of Csp1 was completely repressed by all conditions other than carbon starvation. A less than fivefold increase in induction was monitored for the transient responders Csp5 and Csp6 within the first few hours of carbon starvation. Interestingly, Csp6 exhibited an increased transient induction at the onset as well as after 24 h of starvation. Accumulation of the three proteins was monitored by Western blot analysis using specific antisera. Of the conditions tested, long-term accumulation of these proteins was only detected when Vibrio sp. S14 cells were exposed to carbon and multiple-nutrient starvation. These results are discussed in relation to the recent finding that formation of starvation- and stress-resistant marine Vibrio is induced by carbon but not nitrogen or phosphorus starvation, and that Csp1, Csp5 and Csp6 will allow detailed studies of the carbon starvation stimulon.