The Role of Holliday Junction Recognition Protein and Its Interactions with RNA and the Condensin II Complex in Human Centromeric Chromatin Establishment

The human centromere is the site on each mitotic chromosome where the kinetochore assembles. Centromeric chromatin is epigenetically defined by the presence of nucleosomes containing the histone H3 variant, CENP-A. Establishment and faithful maintenance of CENP-A chromatin at the centromere throughout the lifetime of a cell are crucial pathways for the cell to accurately maintain its ploidy. Understanding how this CENP-A chromatin is tended and what factors are required for its establishment and maintenance is the theme of this work. The first chapter of this work demonstrates the CENP-A chaperone HJURP is sufficient to deposit CENP-A nucleosomes at non-centromeric chromatin, and these nucleosomes are sufficient to nucleate de novo kinetochore formation. The second chapter characterizes an interaction between HJURP and SINE28 ssRNA, demonstrating the importance of the interaction in CENP-A deposition in human cells. The third chapter describes chromatin decondensation activity of HJURP, its interaction with the condensin II complex, and the influence of this interaction on CENP-A deposition in human cells.