Hsc70 Is Not Essential for Thermotolerance but for Barotolerance

摘要

We studied the contribution of Hsc70 to barotolerance by measuring barotolerance in logarithmic phase cells of the Hsc70 (ssb1 and ssb2) deletion mutant and the deletion mutant which carries the Hsc70 gene on the low copy number plasmid and high copy number plasmid. The deletion mutant strain showed higher thermotolerance and slightly lower barotolerance than that of the control strain. The mutant which has Hsc70 gene on multicopy plasmid showed more barotolerance than the strain which has the gene on low copy plasmid. These results suggest that Hsc70 contributes to barotolerance. We also compared the effect of Hsp104 and Hsc70 deletion to barotolerance at different temperatures (20-35 deg C). The effect of Hsp104 deficiency was significant with increase in temperature; however, that of Hsc70 was significant with increase in temperature; however, that of Hsc70 was significant at moderate temperatures. These results suggest Hsp104 contributes to barotolerance at higher temperature and Hsc70 at moderate temperature.