Mediates the ATP-dependent exchange of unmodified histone H2AV for its phosphorylated and acetylated form H2AVK5acS138ph, leading to transcriptional regulation of selected genes by chromatin remodeling. Involved in Notch signaling. Represses E2F target genes. Required for somatic stem cell self-renewal but not for germline stem cell self-renewal. Involved in oogenesis. Component of the Tip60 chromatin-remodeling complex which contains Domino, Tip60, Tra1, Brd8, E(Pc), DMAP1, Pontin, Reptin, Ing3, Act87E, BAP55, Mrg15, MrgBP, Gas41 and YL-1. Isoform B is present at high levels in ovary, in follicle cells, nurse cells and oocyte. Isoform B is also present in germline and somatic stem cells from the germarium. Isoform A is undetectable in adult ovary (at protein level). Isoform A and isoform B are present in 0-12 hours embryonic extracts. During embryonic development, isoform A expression is restricted to the developing nervous system, whereas isoform B is ubiquitously expressed. During postembryonic development, isoform B is found in brain, imaginal disks, lymph glands and salivary glands and isoform A is found in some brain regions, photoreceptor cells and sensory organ precursors (at protein level). Belongs to the SNF2/RAD54 helicase family. SWR1 subfamily.