Structural integrity of centromeric chromatin and faithful chromosome segregation requires Pat1.

The kinetochore (centromeric DNA and associated protein complex) is essential for faithful chromosome segregation and maintenance of genome stability. Here we report that an evolutionarily conserved protein Pat1 is a structural component of Saccharomyces cerevisiae kinetochore and associates with centromeres in a NDC10-dependent manner. Consistent with a role for Pat1 in kinetochore structure and function, a deletion of PAT1 results in delay in sister chromatid separation, errors in chromosome segregation, and defects in structural integrity of centromeric chromatin.