Lipid second messengers and related enzymes in vertebrate rod outer segments
- Instituto de Investigaciones Bioquímicas de Bahía Blanca, Universidad Nacional del Sur and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), B8000FWB Bahía Blanca, Argentina
- 1To whom correspondence should be addressed. e-mail: ngiusto{at}criba.edu.ar
Abstract
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.
- diacylglycerol
- diacylglycerol kinase
- diacylglycerol lipase
- lipid phosphate phosphatase
- monoacylglycerol
- phosphatidic acid
- phospholipase D
Footnotes
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- Abbreviations:
- AT
- acyltransferase
- Cer
- ceramide
- C1P
- ceramide 1-phosphate
- DAG
- diacylglycerol
- DAGL
- diacylglycerol lipase
- DAGK
- diacylglycerol kinase
- DHA
- docosahexaenoic acid
- DRM
- detergent-resistant membrane
- DROS
- ROS from dark-adapted retinas
- Gt
- transducin
- Gtα
- α subunit of transducin
- Gtβγ
- βγ subunits of transducin
- IP3
- inositol 1,4,5-trisphosphate
- IS
- inner segment
- LPA
- lysophosphatidic acid
- LPP
- lipid phosphate phosphatase
- LROS
- ROS from light-adapted retinas
- MAG
- monoacylglycerol
- OS
- outer segment
- PA
- phosphatidic acid
- PC
- phosphatidylcholine
- PDE
- cGMP phosphodiesterase
- PE
- phosphatidylethanolamine
- PI
- phosphatidylinositol
- PI(4,5)P2
- phosphatidylinositol-4,5-bisphosphate
- PIK
- phosphatidylinositol kinase
- PI3K
- phosphoinositide-3-kinase
- PKC
- protein kinase C
- PLA2
- phospholipase A2
- PLC
- phospholipase C
- PLD
- phospholipase D
- PS
- phosphatidylserine
- PTx
- pertussis toxin
- RK
- rhodopsin kinase
- ROS
- rod outer segment
- Sph
- sphingosine
- S1P
- sphingosine 1-phosphate
-
This work was supported by the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), the Agencia Nacional de Promoción Científica y Tecnológica (FONCyT) and the Secretaría General de Ciencia y Tecnología, Universidad Nacional del Sur, Argentina.
- Received October 9, 2009.
- Revision received October 14, 2009.
- Copyright © 2010 by the American Society for Biochemistry and Molecular Biology, Inc.
