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