1-phosphatidylinositol 4-kinase

1-phosphatidylinositol 4-kinase
Phosphatidylinositol 4-kinase homo16mer, Human
EC no.
CAS no.37205-54-2
IntEnzIntEnz view
ExPASyNiceZyme view
MetaCycmetabolic pathway
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, a 1-phosphatidylinositol 4-kinase (EC is an enzyme that catalyzes the chemical reaction

ATP + 1-phosphatidyl-1D-myo-inositol ADP + 1-phosphatidyl-1D-myo-inositol 4-phosphate

Thus, the two substrates of this enzyme are ATP and 1-phosphatidyl-1D-myo-inositol, whereas its two products are ADP and 1-phosphatidyl-1D-myo-inositol 4-phosphate.

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:1-phosphatidyl-1D-myo-inositol 4-phosphotransferase. Other names in common use include phosphatidylinositol kinase (phosphorylating), phosphatidylinositol 4-kinase, phosphatidylinositol kinase, type II phosphatidylinositol kinase, PI kinase, and PI 4-kinase. This enzyme participates in inositol phosphate metabolism and phosphatidylinositol signaling system.

Structural studies[]

As of late 2007, the structure has only been solved for this enzyme. Part of the enzyme was crystallized with its activating partner frequenin.[1]


  1. ^ Strahl T, Huttner IG, Lusin JD, et al. (October 2007). "Structural insights into activation of phosphatidylinositol 4-kinase (Pik1) by yeast frequenin (Frq1)". J. Biol. Chem. 282 (42): 30949–59. doi:10.1074/jbc.M705499200. PMID 17720810.