Candida albicans SSDl can suppress multiple mutations in Saccharomyces cere visiae

Abstract

SUMMARY: The SSD1 gene of Saccharomyces encodes a 160 kDa cytoplasmic protein that can suppress mutations in a number of other genes. A functional homologue of SSD1 from the humanpathogen Candida albicans was isolated on the basis of its ability to restore viabilityat the restrictive temperature in a Saccharomyces cerevisiae swi4 ssdl-d strain. The C. albicans gene, designated CaSSD1, encodes a 1262 aa protein which has 47% identity overall to S. cerevisiae SSDI as well as significant identity to Schizosaccharomyces pombe dis3 and sts5 products. It is shown that CaSSD1 expression is constitutive through the mitotic cell cycle, which is consistent with a role for the protein in cell growth. CaSSD1 rescues the swiP defect in an ssd1-d background when expressed from its own promoteron a single-copy plasmid and under the same conditions can rescue mutations in genes encoding protein phosphatase type 2A catalytic subunits. These data suggest that CaSSD1, like its S. cerevisiae homologue, can limit the effect of mutations on a variety of cellular processes.