Inositol-polyphosphate multikinase

More reference expression dataBioGPSEnsemblUniProtRefSeq (mRNA)RefSeq (protein)Location (UCSC)Chr 10: 58.19 – 58.27 MbChr 10: 71.18 – 71.27 MbPubMed searchWikidata

Inositol-polyphosphate multikinase (EC2.7.1.151, IpK2, IP3/IP4 6-/3-kinase, IP3/IP4 dual-specificity 6-/3-kinase, IpmK, ArgRIII, AtIpk2alpha, AtIpk2beta, inositol polyphosphate 6-/3-/5-kinase) is an enzyme that in humans is encoded by the geneIPMK. Its systematic name is ATP:1D-myo-inositol-1,4,5-trisphosphate 6-phosphotransferase. This enzyme catalyses the following chemical reaction

2 ATP + 1D-myo-inositol 1,4,5-trisphosphate ${\displaystyle ightleftharpoons }$ 2 ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate (overall reaction)

(1a) ATP + 1D-myo-inositol 1,4,5-trisphosphate ${\displaystyle ightleftharpoons }$ ADP + 1D-myo-inositol 1,4,5,6-tetrakisphosphate

(1b) ATP + 1D-myo-inositol 1,4,5,6-tetrakisphosphate ${\displaystyle ightleftharpoons }$ ADP + 1D-myo-inositol 1,3,4,5,6-pentakisphosphate

This enzyme also phosphorylates Ins(1,4,5)P3 to Ins(1,3,4,5)P4, Ins(1,3,4,5)P4 to Ins(1,3,4,5,6)P5, and Ins(1,3,4,5,6)P4 to Ins(PP)P4, isomer unknown.