Probable regulatory subunit of serine/threonine-protein phosphatase PP4 which may play a role in meiosis and embryonic mitosis. Probably in association with catalytic subunit pph-4.1, regulates microtubule severing during oocyte meiosis II by dephosphorylating and likely activating mei-1, a component of the katanin microtubule severing complex. Serine/threonine-protein phosphatase 4 (PP4) occurs in different assemblies of the catalytic and one or more regulatory subunits (By similarity). The catalytic subunit is likely to be pph-4.1 (PubMed:19087961). RNAi-mediated knockdown causes 94 percent embryonic lethality when injected compared to 20 percent when fed. Partially rescues embryonic lethality in gain of function mei-1 (ct46) mutant background.