Centromeric histone H3-like protein; associates with promoters, accessible chromatin, and RNAPII-bound regions; Cse4p associates with centromeres, promoting kinetochore assembly and Sgo1p association with centromeric chromatin; Ipl1p-dependent phosphorylation destabilizes defective kinetochores promoting bi-orientation; phosphorylation by Cdc7p maintains Cse4p at kinetochores and promotes faithful chromosome segregation; regulated by multiple E3 ligases; complements human homolog CENPA mutations