Phosphatidylinositol 1228493 223383644 2008-07-03T21:04:12Z LatitudeBot 6771835 robot Adding: [[ru:Фосфатидилинозитол]] [[Image:Phosphatidylinositol.jpg|thumb|right|250px]|'''Chemical structure of sn-1-stearoyl-2-arachidonoyl phosphatidylinositol''']] '''Phosphatidylinositol''' (abbreviated PtdIns, or PI) is a minor [[phospholipid]] component in the cytosolic side of eukaryotic [[cell membranes]]. Being an amphiphile, this molecule possesses [[lipid polymorphism|polymorphic]] behaviour, that is currently a topic of research in academic study. ==Composition== Phosphatidylinositol is a class of phospholipid, which is made up of [[glycerol]], [[fatty acid]] and the base is replaced by a hexahydric alcohol namely [[inositol]]. This hexahydric alcohol exists as its [[stereoisomer]] - ''myo-inositol''. Upon hydrolysis, they yield 1 mole of glycerol, 2 moles of fatty acid, 1 mole of inositol and 1, 2, or 3 moles of [[phosphoric acid]]s. They are regarded to be the most acidic of all the phospholipids. ==Phosphorylation== It is the substrate for a large number of enzymes which are involved in [[signal transduction|cell signaling]] because it can be [[phosphorylated]] by a variety of [[kinases]] on the hydroxyl groups 3, 4 and 5 on the [[inositol]] ring in seven different combinations. Hydroxyl group two and six can probably not be phosphoroylated because of steric hindrance. All seven variations have been found in animals but only six in plant cells (not phosphatidylinositol (3,4,5)-trisphosphate.<ref name="Muller-Roeber B">{{cite book | title=Inositol Phospholipid Metabolism in Arabidopsis. Characterized and Putative Isoforms of Inositol Phospholipid Kinase and Phosphoinositide-Specific Phospholipase C| last=Muller-Roeber B| first=Pical C| coauthors='''',| date=2002}}</ref>. ==References== <references /> ==See also== * [[PI 3-kinase]] * [[Inositol phosphate]] * [[Phosphatidylinositol 3-phosphate]] * [[Phosphatidylinositol 4-phosphate]] * [[Phosphatidylinositol (3,4)-bisphosphate]] * [[Phosphatidylinositol (3,5)-bisphosphate]] * [[Phosphatidylinositol (4,5)-bisphosphate]] * [[Inositol 1,4,5-triphosphate]] * [[Phosphatidylinositol (3,4,5)-trisphosphate]] * [[inositol pentakisphosphate]] * [[inositol hexaphosphate]] * [[inositol triphosphate receptor]] ==Additional images== <gallery> Image:Membrane lipids.png|[[Membrane lipids]] Image:Phosphatidyl-Inositol.png|Phosphatidyl-inositol Image:Inositol chair.png|[[Inositol]] Image:Glycerine chemical structure.png|[[Glycerol]] </gallery> ==External links== * {{MeshName|Phosphatidylinositols}} * [http://www.lipidlibrary.co.uk/Lipids/pi/index.htm Phosphatidylinositol at Lipid Library] [[Category:Phospholipids]] [[Category:Membrane biology]] {{Cell-biology-stub}} {{Phospholipids}} [[fr:Phosphatidylinositol]] [[ru:Фосфатидилинозитол]] [[fi:Fosfatidyyli-inositoli]]