. "Catalysis of the reaction: ATP + 1-phosphatidyl-1D-myo-inositol 5-phosphate = ADP + 1-phosphatidyl-1D-myo-inositol 4,5-bisphosphate." . . "1-phosphatidylinositol-5-phosphate kinase" . "1-phosphatidylinositol-5-phosphate 4-kinase activity" . "ATP:1-phosphatidyl-1D-myo-inositol-5-phosphate 4-phosphotransferase activity" . "PIP4K" . "type II PIP kinase activity" . . .