title: TNAP, an Essential Player in Membrane Lipid Rafts of Neuronal Cells.
abstract: The tissue non-specific alkaline phosphatase (TNAP) is a glycosyl-phosphatidylinositol (GPI) anchored glycoprotein which exists under different forms and is expressed in different tissues. As the other members of the ecto-phosphatase family, TNAP is targeted to membrane lipid rafts. Such micro domains enriched in particular lipids, are involved in cell sorting, are in close contact with the cellular cytoskeleton and play the role of signaling platform. In addition to its location in functional domains, the extracellular orientation of TNAP and the fact this glycoprotein can be shed from plasma membranes, contribute to its different phosphatase activities by acting as a phosphomonoesterase on various soluble substrates (inorganic pyrophosphate -PPi-, pyridoxal phosphate -PLP-, phosphoethanolamine -PEA-), as an ectonucleotidase on nucleotide-phosphate and presumably as a phosphatase able to dephosphorylate phosphoproteins and phospholipids associated to cells or to extra cellular matrix. More and more data accumulate on an involvement of the brain TNAP both in physiological and pathological situations. This review will summarize what is known and expected from the TNAP localization in lipid rafts with a particular emphasis on the role of a neuronal microenvironment on its potential function in the central nervous system.
authors.affiliation: Département de Virologie, Institut Pasteur, Unité Des Stratégies Antivirales, F-75015, Paris, France, myriam.ermonval@pasteur.fr.
authors.forename: Myriam
authors.initials: M
authors.lastname: Ermonval
authors.forename: Florence
authors.initials: F
authors.lastname: Baychelier
authors.forename: Caroline
authors.initials: C
authors.lastname: Fonta
mesh_terms: D000469:Alkaline Phosphatase / Q000502:physiology*; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D008563:Membrane Lipids / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism* / Q000648:ultrastructure; D060066:Protein Interaction Maps / Q000502:physiology
chemical_list: D008563:Membrane Lipids; D000469:Alkaline Phosphatase