Phosphatase that converts 3′(2′)-phosphoadenosine 5′-phosphate (PAP) to AMP and inositol 1,4-bisphosphate (Ins(1,4)P2) to inositol 4-phosphate (PubMed:10675562). Is also able to hydrolyze adenosine 3′-phosphate 5′-phosphosulfate (PAPS) to adenosine 5′-phosphosulfate (APS) (By similarity). Probably prevents the toxic accumulation of PAP, a compound which inhibits a variety of proteins, including PAPS-utilizing enzymes such as sulfotransferases, and RNA processing enzymes. Could also play a role in inositol recycling and phosphoinositide metabolism. Is not active on 3′-AMP, inositol-1-phosphate and inositol-1,4,5-triphosphate (PubMed:10675562).
