Regulation of thioltransferase activity from Schizosaccharomyces pombe

Abstract

Thioltransferase (TTase), also known as glutaredoxin (Grx), is an enzyme catalyzing the reduction of a variety of disulfide compounds and acting as a cofactor for various enzymes such as ribonucleotide reductase. The Schizosaccharomyces pombe cells, exponentially grown in rich medium at 30 degrees C, were shifted to 20 degrees C and 35 degrees C. The yeast cells, shifted to 35 degrees C, showed higher TTase activity than the cells continuously grown at 30 degrees C, whereas the yeast cells, shifted to 20 degrees C, gave lower TTase activity. The S. pombe cells, exponentially grown in minimal medium and shifted from 30 degrees C to 35 degrees C and 40 degrees C, produced higher TTase activity. When the S. pombe cells were initially incubated in rich and minimal media at three different temperatures (25 degrees C, 30 degrees C and 35 degrees C), they showed higher TTase activity at higher temperature. These results suggest that the TTase activity of S. pombe is regulated by temperature.