Synonyms: Background:Membrane-bound phosphatidylinositol-4 kinase(PI4-kinase) that catalyzes the phosphorylation of phosphatidylinositol(PI) to phosphatidylinositol 4-phosphate(PI4P), a lipid that plays important roles in endocytosis, Golgi function, protein sorting and membrane trafficking and is required for prolonged survival of neurons. Besides, phosphorylation of phosphatidylinositol(PI) to phosphatidylinositol 4-phosphate(PI4P) is the first committed step in the generation of phosphatidylinositol 4,5-bisphosphate(PIP2), a precursor of the second messenger inositol 1,4,5-trisphosphate(InsP3).