Probable subunit of a chromatin-remodeling complex. Involved in DNA repair. Required for multicellular development of all organs. Component of the INO80 chromatin-remodeling complex (Probable). Interacts with EEN (PubMed:31418686). Localized in the nucleoplasm of interphase cells (PubMed:19679120). However, dispersed into the cytoplasm in dividing cells at metaphase (PubMed:19679120). Expressed ubiquitously in seedlings, roots, leaves, buds, flowers and siliques. Moderately dwarfed plants with small organs composed of small-sized cells (PubMed:19679120). Higher density of developmentally delayed stomata (PubMed:19679120). Hypersensitivity to DNA-damaging reagents such as hydroxyurea, methylmethane sulfonate, and bleocin (PubMed:19679120). Differential expression of several genes (PubMed:31418686). The double mutant ref6-1 arp5-1 is insensitive to ethylene (ET) and exhibits reduced levels of EIN2 associated with a shift of the chromatin landscape to a repressive state at its locus (e.g. H3K27me3 and H2A.Z) (PubMed:31418686). Belongs to the actin family. ARP5 subfamily.