Actin Related Protein 8 (ACTR8)

Human Arp8 (hArp8), an ortholog of yeast nuclear Arp8, was recently found to be associated with the hINO80-chromatin remodeling complex along with hArp5.This is the first example where a member of the actin family is found to be associated with mitotic chromosomes. Expression of truncated hArp8 proteins and depletion of endogenous hArp8 by RNA interference caused misalignment of mitotic chromosomes, suggesting that chromosome-associated hArp8 has a role in chromosome behavior. In contrast, depletion of hIno80 and hArp5 did not cause misalignment of chromosomes, suggesting that the role of hArp8 at mitotic chromosomes is independent of the activity of hINO80 complexes. These findings provide the first insight into a novel function of actin family members in mitosis.