Phosphatase that specifically hydrolyzes the 5-phosphate of inositol 1,4,5-trisphosphate to inositol 1,4-bisphosphate, and inositol 1,3,4,5-tetrasphosphate to inositol 1,3,4-trisphosphate (PubMed:8013665, PubMed:8626616, PubMed:8769125). Plays a crucial role in the survival of cerebellar Purkinje cells (By similarity).