May be required for replication-independent chromatin assembly. Component of the HIRA complex made of UBN1, UBN2, ASF1A, CABIN1 and HIRA. Expressed at low levels in seedlings. No visible phenotype (PubMed:25086063, PubMed:25600486). The double mutant hira-1 cabin1-2 has aborted and fewer viable seeds (PubMed:25600486).