SYNTHESIS OF HEAT-SHOCK PROTEINS BY YEAST DEBARYOMYCES-VANRIJI CELLS GROWN AT VARIOUS TEMPERATURES

The pattern of heat-shock proteins (HSPs) and thermotolerance were stu died in the yeast Debaryomyces vanriji, strain GK46-2, isolated from a hot spring and in its thermotolerant mutant GK46-2tr. Yeasts were gro wn at 5, 30, or 41 degrees C and then exposed to 46 degrees C for 30 m in (heat shock). C-14-leucine-labeled HSPs were separated by one-dimen sional PAGE. The GK46-2 cells responded to heat shock by the synthesis of proteins with mol wts of 100, 90, 82, 75, 67, and 32 kD. The highe r the growth temperature, the more tolerant were yeast cells to heat s hock. This thermotolerance was correlated with a more pronounced induc tion of the protein with a mol wt of 100 kD, with constitutive synthes is of proteins with mol wts of 90, 82, and 75 kD, and with enhanced sy nthesis of these proteins in response to heat shock.