A GTPase switch maintains CENP-A at centromeric chromatin.

摘要

Centromeres are unique genetic loci within the chromosomes that contribute to the mechanisms that ensure genome inheritance during cell division. With very few exceptions, they are epigenetic features of the chromosome and derive their functional identity not from their DNA sequence, but from distinct features within centromeric chromatin that incorporates the histone H3 variant CENP-A (also known as cenH3) and its associated structural and replicative machinery. Unlike the genes, for which replication of DNA ensures replication of locus identity, centromeric chromatin is disrupted by the passage of the DNA replication fork4 and specific mechanisms are required to allow for CENP-A reloading and maintenance during the cell cycle.