Regulation of PLC-mediated signalling in vivo by CDP-diacylglycerol synthase.
CDP-diacylglycerol synthase (CDS) is an enzyme required for the regeneration of the signalling molecule phosphatidylinositol-4,5-bisphosphate (PtdlnsP2) from phosphatidic acid. A photo-receptor cell-specific isoform of CDS from Drosophila is a key regulator of phototransduction, a G-protein-coupled signalling cascade mediated by phospholipase C. cds mutants cannot sustain a light-activated current as a result of depletion of PtdlnsP2. Overexpression of CDS increases the amplitude of the light response, demonstrating that availability of PtdlnsP2 is a determinant in the gain of this pathway. cds mutants undergo light-dependent retinal degeneration which can be suppressed by a mutation in phospholipase C. Thus, enzymes involved in PtdlnsP2 metabolism regulate phosphoinositide-mediated signalling cascades in vivo.
Wu
L
L
Howard Hughes Medical Institute, University of California at San Diego, La Jolla 92093-0649.
Niemeyer
B
B
Colley
N
N
Socolich
M
M
Zuker
C S
CS
D000595:Amino Acid Sequence; D000818:Animals; D010717:CDPdiacylglycerol-Serine O-Phosphatidyltransferase / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila; D019204:GTP-Binding Proteins / Q000378:metabolism; D066298:In Vitro Techniques; D008027:Light; D008969:Molecular Sequence Data; D009154:Mutation; D009410:Nerve Degeneration; D010712:Phosphatidic Acids / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate; D043265:Phosphatidylinositol Diacylglycerol-Lyase; D018129:Phosphatidylinositol Phosphates / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism* / Q000648:ultrastructure; D015398:Signal Transduction
D010712:Phosphatidic Acids; D019269:Phosphatidylinositol 4,5-Diphosphate; D018129:Phosphatidylinositol Phosphates; D010717:CDPdiacylglycerol-Serine O-Phosphatidyltransferase; D010727:Phosphoric Diester Hydrolases; D019204:GTP-Binding Proteins; D043265:Phosphatidylinositol Diacylglycerol-Lyase