title: Synthesis of myo-inositol 1,3,4,5,6-pentakisphosphate from inositol phosphates generated by receptor activation.
abstract: myo-[3H]Inositol 1,3,4,5,6-pentakisphosphate can be made from myo-[3H]inositol 1,4,5-trisphosphate in a rat brain homogenate or soluble fraction. Although D-myo-inositol 3,4,5,6-tetrakisphosphate can be phosphorylated by a soluble rat brain enzyme to give myo-inositol 1,3,4,5,6-pentakisphosphate, it is not an intermediate in the pathway from myo-inositol 1,4,5-trisphosphate. The intermediates in the above pathway are myo-inositol 1,3,4,5-tetrakisphosphate, myo-inositol 1,3,4-trisphosphate and myo-inositol 1,3,4,6-tetrakisphosphate [Shears, Parry, Tang, Irvine, Michell & Kirk (1987) Biochem. J. 246, 139-147; Balla, Guillemette, Baukal & Catt (1987) J. Biol. Chem. 262, 9952-9955], and it is catalysed by soluble kinase activities of similar anion-exchange mobility and Mr value. Compounds with chromatographic and chemical properties consistent with the structures myo-inositol 1,3,4,5-tetrakisphosphate, myo-inositol 1,3,4,6-tetrakisphosphate and myo-inositol 3,4,5,6-tetrakisphosphate are present in avian erythrocytes, human 1321 N1 astrocytoma cells and primary-cultured murine bone-marrow-derived macrophages. The amounts of these inositol tetrakisphosphates rise upon muscarinic cholinergic stimulation of the astrocytoma cells or stimulation of macrophages with platelet-activating factor.
authors.affiliation: Smith Kline & French Research Ltd., Welwyn, Herts, U.K.
authors.forename: L R
authors.initials: LR
authors.lastname: Stephens
authors.forename: P T
authors.initials: PT
authors.lastname: Hawkins
authors.forename: C J
authors.initials: CJ
authors.lastname: Barker
authors.forename: C P
authors.initials: CP
authors.lastname: Downes
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D003600:Cytosol / Q000378:metabolism; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate; D007295:Inositol Phosphates / Q000096:biosynthesis* / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D010766:Phosphorylation; D010972:Platelet Activating Factor / Q000494:pharmacology; D051381:Rats; D011956:Receptors, Cell Surface / Q000187:drug effects / Q000378:metabolism*; D013403:Sugar Phosphates / Q000096:biosynthesis* / Q000378:metabolism*
chemical_list: D007295:Inositol Phosphates; D010972:Platelet Activating Factor; D011956:Receptors, Cell Surface; D013403:Sugar Phosphates; C013571:inositol pentaphosphate; D015544:Inositol 1,4,5-Trisphosphate; D000255:Adenosine Triphosphate