Lipid second messengers and related enzymes in vertebrate rod outer segments.
Rod outer segments (ROSs) are specialized light-sensitive organelles in vertebrate photoreceptor cells. Lipids in ROS are of considerable importance, not only in providing an adequate environment for efficient phototransduction, but also in originating the second messengers involved in signal transduction. ROSs have the ability to adapt the sensitivity and speed of their responses to ever-changing conditions of ambient illumination. A major contributor to this adaptation is the light-driven translocation of key signaling proteins into and out of ROS. The present review shows how generation of the second lipid messengers from phosphatidylcholine, phosphatidic acid, and diacylglycerol is modulated by the different illumination states in the vertebrate retina. Findings suggest that the light-induced translocation of phototransduction proteins influences the enzymatic activities of phospholipase D, lipid phosphate phosphatase, diacylglyceride lipase, and diacylglyceride kinase, all of which are responsible for the generation of the second messenger molecules.
Giusto
Norma M
NM
Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Bahía Blanca, Argentina. ngiusto@criba.edu.ar
Pasquaré
Susana J
SJ
Salvador
Gabriela A
GA
Ilincheta de Boschero
Mónica G
MG
D000818:Animals; D004075:Diglycerides / Q000378:metabolism; D006801:Humans; D055537:Light Signal Transduction; D050356:Lipid Metabolism; D008055:Lipids / Q000502:physiology*; D010712:Phosphatidic Acids / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D021381:Protein Transport; D012374:Rod Cell Outer Segment / Q000201:enzymology* / Q000378:metabolism*; D015290:Second Messenger Systems / Q000502:physiology*
D004075:Diglycerides; D008055:Lipids; D010712:Phosphatidic Acids; D010713:Phosphatidylcholines