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Type I inositol polyphosphate 5-phosphatase I Type I inositol polyphosphate 5-phosphatase I (INPP5A) hydrolyzes the 5-phosphate from inositol 1,3,4,5-tetrakisphosphate [I(1,3,4,5)P4] and inositol 1,4,5-trisphosphate [I(1,4,5)P3]. It belongs to a family of Mg2+-dependent inositol polyphosphate 5-phosphatases, which hydrolyze the 5-phosphate from the inositol ring of various 5-position phosphorylated phosphoinositides (PIs) and inositol phosphates (IPs), and to the large EEP (exonuclease/endonuclease/phosphatase) superfamily that contains functionally diverse enzymes that share a common catalytic mechanism of cleaving phosphodiester bonds. As the substrates of INPP5A mobilize intracellular calcium ions, INPP5A is a calcium signal-terminating enzyme. In platelets, phosphorylated pleckstrin binds and activates INPP5A in a 1:1 complex, and accelerates the degradation of the calcium ion-mobilizing I(1,4,5)P3. |
Jiyao W et al.(2023). "The conserved domain database in 2023.",