CHARACTERIZATION OF MUTANTS DEVOID OF NEUTRAL TREHALASE ACTIVITY IN THE FISSION YEAST SCHIZOSACCHAROMYCES-POMBE - PARTIAL PROTECTION FROM HEAT-SHOCK AND HIGH-SALT STRESS

Exposure of cells of Schizosaccharomyces pombe to heat shock or osmoti c upshift results in an increased level of neutral trehalase activity, which is responsible for hydrolysis of intracellular trehalose. We co nstructed S. pombe mutants lacking neutral trehalase activity by gene replacement at the newly defined ntp(+) locus. Analysis of these mutan ts revealed that a twofold increase in trehalose accumulation, enhance d acquired thermoresistance, and marked salt tolerance characterized t heir ability to grow in liquid and solid media. Analysis of the expres sion of the trehalase gene under heat shock and osmotic upshift reveal ed the transcriptional activation of ntp1(+) in response to both stres ses.