Inositol-trisphosphate 3-kinase

In enzymology, an inositol-trisphosphate 3-kinase is an enzyme that catalyzes the chemical reaction


 * ATP + 1D-myo-inositol 1,4,5-trisphosphate $$\rightleftharpoons$$ ADP + 1D-myo-inositol 1,3,4,5-tetrakisphosphate

Thus, the two substrates of this enzyme are ATP and 1D-myo-inositol 1,4,5-trisphosphate, whereas its two products are ADP and 1D-myo-inositol 1,3,4,5-tetrakisphosphate.

This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:1D-myo-inositol-1,4,5-trisphosphate 3-phosphotransferase. Other names in common use include 1D-myo-inositol-trisphosphate 3-kinase, and Ins(1,4,5)P3 3-kinase. This enzyme participates in 3 metabolic pathways: inositol phosphate metabolism, calcium signaling pathway, and phosphatidylinositol signaling system. This enzyme has at least one effector, Calcium.

Structural studies
As of late 2007, 3 structures have been solved for this class of enzymes, with PDB accession codes, , and.