Cleaves a beta-phosphate from the diphosphate groups in PP-InsP5 (diphosphoinositol pentakisphosphate), PP-InsP4 and [PP]2-InsP4 (bisdiphosphoinositol tetrakisphosphate), suggesting that it may play a role in signal transduction (PubMed:10777568, PubMed:12370170). Can also catalyze the hydrolysis of diadenosine 5′,5”’-P1,P6-hexaphosphate (Ap6A) but not diadenosine 5′,5”’-P1,P5-pentaphosphate (Ap5A) and the major reaction products are ADP and p4a from Ap6A (PubMed:12370170). Also able to hydrolyze 5-phosphoribose 1-diphosphate (PubMed:12370170). Does not play a role in U8 snoRNA decapping activity (By similarity). Binds U8 snoRNA (By similarity).
