title: Emerging roles of phosphatidylinositol monophosphates in cellular signaling and trafficking.
abstract: The phosphoinositide metabolism that is highly controlled by a set of kinases, phosphatases and phospholipases leads to the production of several second messengers playing critical roles in intracellular signal transduction mechanisms. Recent discoveries have unraveled unexpected roles for the three phosphatidylinositol monophosphates, PtdIns(3)P, PtdIns(4)P and PtdIns(5)P, that appear now as important lipid messengers able to specifically interact with proteins. The formation of functionally distinct and independently regulated pools of phosphatidylinositol monophosphates probably contributes to the specificity of the interactions with their targets. The relative enrichment of organelles in a particular species of phosphoinositides (i.e. PtdIns(3)P in endosomes, PtdIns(4)P in Golgi and PtdIns(4,5)P2 in plasma membrane) suggests the notion of lipid-defined organelle identity. PtdIns(3)P is now clearly involved in vesicular trafficking by interaction with a set of FYVE domain-containing proteins both in yeast and in mammals. PtdIns(4)P, which until now was only considered as a precursor for PtdIns(4,5)P2, appears as a regulator on its own, by recruiting a set of proteins to the trans-Golgi network. PtdIns(5)P, the most recently discovered inositol lipid, is also emerging as a potentially important signaling molecule.
authors: Inserm U563-CPTP, IFR 30, Department of Oncogenesis and signaling in haematopoïetic cells, CHU Purpan, 31024 Toulouse, France.
authors: Caroline
authors: C
authors: Pendaries
authors: Hélène
authors: H
authors: Tronchère
authors: Claire
authors: C
authors: Racaud-Sultan
authors: Frédérique
authors: F
authors: Gaits-Iacovoni
authors: Sophie
authors: S
authors: Coronas
authors: Stéphane
authors: S
authors: Manenti
authors: Marie-Pierre
authors: MP
authors: Gratacap
authors: Monique
authors: M
authors: Plantavid
authors: Bernard
authors: B
authors: Payrastre
mesh_terms: D000818:Animals; D006056:Golgi Apparatus / Q000187:drug effects / Q000502:physiology; D006801:Humans; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D018129:Phosphatidylinositol Phosphates / Q000502:physiology*; D015290:Second Messenger Systems / Q000502:physiology
chemical_list: D018129:Phosphatidylinositol Phosphates; C055525:phosphatidylinositol 3-phosphate; C037178:phosphatidylinositol 4-phosphate; C113567:phosphatidylinositol 5-phosphate; D019869:Phosphatidylinositol 3-Kinases