title: PtdIns(4)P signalling and recognition systems.
abstract: The Golgi apparatus is a sorting platform that exchanges extensively with the endoplasmic reticulum (ER), endosomes (Es) and plasma membrane (PM) compartments. The last compartment of the Golgi, the trans-Golgi Network (TGN) is a large complex of highly deformed membranes from which vesicles depart to their targeted organelles but also are harbored from retrograde pathways. The phosphoinositide (PI) composition of the TGN is marked by an important contingent of phosphatidylinositol-4-phosphate (PtdIns(4)P). Although this PI is present throughout the Golgi, its proportion grows along the successive cisternae and peaks at the TGN. The levels of this phospholipid are controlled by a set of kinases and phosphatases that regulate its concentrations in the Golgi and maintain a dynamic gradient that determines the cellular localization of several interacting proteins. Though not exclusive to the Golgi, the synthesis of PtdIns(4)P in other membranes is relatively marginal and has unclear consequences. The significance of PtdIns(4)P within the TGN has been demonstrated for numerous cellular events such as vesicle formation, lipid metabolism, and membrane trafficking.
authors.affiliation: College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK.
authors.forename: Marc
authors.initials: M
authors.lastname: Lenoir
authors.forename: Michael
authors.initials: M
authors.lastname: Overduin
mesh_terms: D019870:1-Phosphatidylinositol 4-Kinase / Q000502:physiology; D033942:Adaptor Proteins, Vesicular Transport / Q000737:chemistry / Q000502:physiology; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000502:physiology; D002352:Carrier Proteins / Q000737:chemistry / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors / Q000737:chemistry / Q000502:physiology; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000502:physiology; D018129:Phosphatidylinositol Phosphates / Q000737:chemistry / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D033942:Adaptor Proteins, Vesicular Transport; D001426:Bacterial Proteins; C475910:CLINT1 protein, human; D002352:Carrier Proteins; C429024:GOLPH3 protein, human; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; D018129:Phosphatidylinositol Phosphates; C539733:SidM protein, Legionella pneumophila; C037178:phosphatidylinositol 4-phosphate; C410230:tamalin protein, human; D019870:1-Phosphatidylinositol 4-Kinase