InterPro domain: IPR008656

This entry represents inositol-tetrakisphosphate 1-kinase, which is also called inositol 1,3,4-trisphosphate 5/6-kinase.

Inositol-tetrakisphosphate 1-kinase can phosphorylate various inositol polyphosphates, such as Ins(3,4,5,6)P4 or Ins(1,3,4)P3. Phosphorylation of Ins(3,4,5,6)P4 at position 1 forms Ins(1,3,4,5,6)P5 which has regulatory importance, since Ins(3,4,5,6)P4 is an inhibitor of plasma membrane Ca(2+)-activated Cl(-) channels. Phosphorylation of Ins(1,3,4)P3 on O-5 and O-6 forms Ins(1,3,4,6)P4, an essential molecule in the hexakisphosphate (InsP6) pathway [ 1 , 2 , 3 , 4 , 5 ].

1. Isolation of inositol 1,3,4-trisphosphate 5/6-kinase, cDNA cloning and expression of the recombinant enzyme. J. Biol. Chem. 271, 11904-10
2. Inositol 1,3,4-trisphosphate 5/6-kinase is a protein kinase that phosphorylates the transcription factors c-Jun and ATF-2. J. Biol. Chem. 276, 40998-1004
3. Regulation of Ins(3,4,5,6)P(4) signaling by a reversible kinase/phosphatase. Curr. Biol. 12, 477-82
4. Inositol 1,3,4-trisphosphate 5/6-kinase inhibits tumor necrosis factor-induced apoptosis. J. Biol. Chem. 278, 43645-53
5. Integration of inositol phosphate signaling pathways via human ITPK1. J. Biol. Chem. 282, 28117-25