HIRA is a histone chaperone that preferentially places the variant histone H3.3 in nucleosomes. Orthologs of this protein in yeast, flies, and plants are necessary for the formation of transcriptionally silent heterochomatin. It plays an important role in the formation of the senescence-associated heterochromatin foci. These foci likely mediate the irreversible cell cycle changes that occur in senescent cells. It is considered the primary candidate protein in some haploinsufficiency syndromes such as DiGeorge syndrome, and insufficient production of the gene may disrupt normal embryonic development.

HUMAN

2-8°C (short-term); -20°C (long-term)