Chromatin Assembly Factor 1, Subunit A (CHAF1A)

The predicted 938-amino acid protein appears to be highly charged and has an isoelectric point of 5.5. It has a PEST (proline-glutamic acid-serine-threonine) box near the N terminus that is associated with proteins of short half-lives.Mutations in CHAF1A prevented association with Hp1 in heterochromatin in cells that were not in S phase and the formation of CHAF1-Hp1 complexes in nascent chromatin during DNA replication in vitro. These data suggested that CHAF1A has a heterochromatin-specific function distinct from its nucleosome assembly function during S phase. Just before mitosis, CHAF1A and some HP1 progressively dissociate from heterochromatin concomitant with histone H3 phosphorylation. The HP1 proteins reassociate with chromatin at the end of mitosis, as histone H3 is dephosphorylated.