title: The phosphatidylinositol 4-kinases: don't call it a comeback.
abstract: Phosphatidylinositol 4-phosphate (PtdIns4P) is a quantitatively minor membrane phospholipid which is the precursor of PtdIns(4,5)P               (2) in the classical agonist-regulated phospholipase C signalling pathway. However, PtdIns4P also governs the recruitment and function of numerous trafficking molecules, principally in the Golgi complex. The majority of phosphoinositides (PIs) phosphorylated at the D4 position of the inositol headgroup are derived from PtdIns4P and play roles in a diverse array of fundamental cellular processes including secretion, cell migration, apoptosis and mitogenesis; therefore, PtdIns4P biosynthesis can be regarded as key point of regulation in many PI-dependent processes.Two structurally distinct sequence families, the type II and type III PtdIns 4-kinases, are responsible for PtdIns4P synthesis in eukaryotic organisms. These important proteins are differentially expressed, localised and regulated by distinct mechanisms, indicating that the enzymes perform non-redundant roles in trafficking and signalling. In recent years, major advances have been made in our understanding of PtdIns4K biology and here we summarise current knowledge of PtdIns4K structure, function and regulation.
authors.affiliation: Centre for Molecular Cell Biology, Department of Inflammation, Division of Medicine, University College London, Rowland Hill Street, Hampstead, NW3 2PF, London, United Kingdom, s.minogue@medsch.ucl.ac.uk.
authors.forename: Shane
authors.initials: S
authors.lastname: Minogue
authors.forename: Mark G
authors.initials: MG
authors.lastname: Waugh
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis; D002465:Cell Movement; D005057:Eukaryotic Cells / Q000166:cytology / Q000201:enzymology*; D005786:Gene Expression Regulation; D006056:Golgi Apparatus / Q000201:enzymology; D006801:Humans; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000096:biosynthesis*; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D015290:Second Messenger Systems; D010738:Type C Phospholipases / Q000235:genetics / Q000378:metabolism
chemical_list: D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; C037178:phosphatidylinositol 4-phosphate; D019870:1-Phosphatidylinositol 4-Kinase; D010738:Type C Phospholipases