title: Loss of receptor regulation by a phospholipase D1 mutant unresponsive to protein kinase C.
abstract: Activation of phosphatidylcholine-specific phospholipase D (PLD) constitutes an important part of the cellular response to agonist signaling. PLD1 is stimulated in vitro in a direct and synergistic manner by protein kinase C (PKC), ADP-ribosylation factor (ARF) and Rho family members. However, the direct and specific role of each of these effectors in agonist-stimulated PLD activation is poorly understood. We have used transposon mutagenesis to generate a library of PLD1 alleles containing random pentapeptide insertions. Forty-five alleles were characterized to identify functionally important regions. Use of an allele unresponsive to PKC, but otherwise seemingly normal, to examine coupling of PLD1 to a subset of G-protein-coupled receptors demonstrates for the first time direct stimulation of PLD1 in vivo by PKC and reveals that this direct stimulation is unexpectedly critical for PLD1 activation.
authors.affiliation: Molecular and Cellular Biology Program, SUNY at Stony Brook, Stony Brook, NY 11794-8651, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Y M
authors.initials: YM
authors.lastname: Altshuller
authors.forename: S M
authors.initials: SM
authors.lastname: Hammond
authors.forename: F
authors.initials: F
authors.lastname: Hayes
authors.forename: A J
authors.initials: AJ
authors.lastname: Morris
authors.forename: M A
authors.initials: MA
authors.lastname: Frohman
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D019556:COS Cells; D002460:Cell Line; D004789:Enzyme Activation; D019204:GTP-Binding Proteins / Q000378:metabolism; D015723:Gene Library; D006801:Humans; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D010739:Phospholipase D / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000502:physiology*; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D011493:Protein Kinase C; D010739:Phospholipase D; C106801:phospholipase D1; D019204:GTP-Binding Proteins