Has phosphatase activity toward PtdIns(4,5)P2, PtdIns(3,4,5)P3 and Ins(1,4,5)P3. Has a higher substrate affinity toward PtdIns(4,5)P2. Required for secondary wall synthesis and actin organization in fiber cells. a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-4,5-bisphosphate) + H2O = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol 4-phosphate) + phosphate a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4,5-trisphosphate) + H2O = a 1,2-diacyl-sn-glycero-3-phospho-(1D-myo-inositol-3,4-bisphosphate) + phosphate 1D-myo-inositol 1,4,5-trisphosphate + H2O = 1D-myo-inositol 1,4-bisphosphate + phosphate Optimum pH is 6.5 with Ins(1,4,5)P3 as substrate, 7.5 with PtdIns(3,4,5)P3 as substrate, and 6.5-8.5 with PtdIns(4,5)P2 as substrate. Optimum temperature is 22 degrees Celsius with Ins(1,4,5)P3 as substrate, and 22-37 degrees Celsius with PtdIns(4,5)P2 and PtdIns(3,4,5)P3 as substrates. Predominantly expressed in interfascicular fibers and vascular bundles. Expressed in seedlings, stems, roots and flowers. Expressed at lower level in mature leaves. Belongs to the inositol polyphosphate 5-phosphatase family.