Overexpression of a novel gene , Cms1, can rescue the growth arrest of a Saccharomyces cerevisiae mcm10 suppressor

MCM10 protein is an essential replication factor involved in the initiation of DNA replication. A mcm10 mutan (mcm10-1) of budding yeast shows a growth arrest at 37 C. In the present work, we have isolated a mcm10-1 suppressor strain, which grows at 37 C. Interestingly, this mcm10-1 suppressor undergoes cell Cycle arrest at 14 C. A novel gene, YLR003c, is identified by high-copy complementation of this suppressor. We called it as Cms1 (Complementation of Mcm 10 Suppressor). Furthermore, the experiments of trans- formation show that cells of mcm10-1 suppressor with high-copy plasmid but not low-copy plasmid grow at 14 C, indicating that overexpression of Cms1 can rescue the growth arrest of this mcm10 suppressor at non-permissive temperature. These results suggest that CMS1 protein may functionally interact with MCM10 protein and play a role in the regulation of DNA replication and cell cycle control.