Rmi1, a member of the Sgs1–Top3 complex in budding yeast, contributes to sister chromatid cohesion

Abstract

The Saccharomyces cerevisiae RecQ-mediated genome instability (Rmi1) protein was recently identified as the third member of the slow growth suppressor 1-DNA topoisomerase III (Sgs1-Top3) complex, which is required for maintaining genomic stability. Here, we show that cells lacking RMI1 have a mitotic delay, which is partly dependent on the spindle checkpoint, and are sensitive to the microtubule depolymerizing agent benomyl. We show that rmi1 and top3 single mutants are defective in sister chromatid cohesion, and that deletion of SGS1 suppresses benomyl sensitivity and the cohesion defect in these mutant cells. Loss of RAD51 also suppresses the cohesion defect of rmi1 mutant cells. These results indicate the existence of a new pathway involving Rad51 and Sgs1-Top3-Rmi1, which leads to the establishment of sister chromatid cohesion.