Regulation of Kinetochore Function in Yeast by Modification of the Core Region of the Centromeric Nucleosome

Centromeres are the regions of the chromosome where the kinetochore is assembled, and they establish a physical link between the centromeric chromatin and the microtubule for chromosome segregation in mitosis. In Saccharomyces cerevisiae, centromeric chromatin is defined by a single nucleosome that contains the histone H3 variant CENP-A Cse4 instead of canonical H3. The extended N-terminus of Cse4 interacts with Okp1/ Ame1 (the S. cerevisiae homologs of human CENP-Q/ CENP-U), which are components of the Ctf19 /CCAN complex, and recruits the inner kinetochore proteins to centromeric chromatin. In this project, we will investigate the function of the core region of the CENP-A Cse4 nucleosome in kinetochore assembly and centromere function in S. cerevisiae.