Light Activation of Phosphatidylethanolamine N-Methyltransferase in Rod Outer Segments and its Modulation by Association States of Transducin

Roque, Marta Elena; Salvador, Gabriela Alejandra; Giusto, Norma M.

doi:10.1006/exer.1999.0738

Cited by 10 publications

(7 citation statements)

References 38 publications

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“…However, evidence of the role of DAGL in Drosophila phototransduction has been reported (Huang et al, 2004;Minke and Parnas, 2006). Furthermore, several studies have demonstrated that the enzymes involved in ROS phospholipid turnover are modulated by light (Castagnet and Giusto, 1993;Ghalayini and Anderson, 1992;Giusto et al, 2000;Guo et al, 1997;Huang et al, 2000;Pasquare et al, 2008;Rajala et al, 2002;Roque et al, 1999;Salvador and Giusto, 2006).…”

Section: Discussionmentioning

confidence: 99%

“…We have previously described diacylglyceride lipase (DAGL) activity in ROS on the premise that the diacylglycerol produced from phosphatidic acid (PA) for lipid phosphate phosphatases (LPP) activity is metabolized to monoacylglycerol (Pasquare de Garcia and Giusto, 1986;Pasquare and Giusto, 1993;Pasquare et al, 2000;Perez Roque et al, 1998). Modulation by light in ROS lipid metabolism enzymes such as phospholipase C (Ghalayini and Anderson, 1992), phospholipase A2 (Castagnet and Giusto, 1993), phosphatidylethanolamine N-methyltransferase (Roque et al, 1999), diacylglycerol kinase (Huang et al, 2000), PAP2 (Pasquare et al, 2008(Pasquare et al, , 2000, phosphoinositide-3-kinase (Guo et al, 1997;Rajala et al, 2002), and phospholipase D (Salvador and Giusto, 2006) has also been reported. Lipid phosphates initiate key signaling cascades in cell activation.…”

Section: Introductionmentioning

confidence: 99%

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Diacylglyceride lipase activity in rod outer segments depends on the illumination state of the retina

Pasquaré

Giusto

2008

Neurochemistry International

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Diacylglyceride lipase activity in rod outer segments depends on the illumination state of the retina

Pasquaré

Giusto

2008

Neurochemistry International

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“…The activities of enzymes involved in ROS phospholipid turnover such as PLC ( 3,46,68,69 ), phospholipase A2 (PLA2) ( 70 ), phosphatidylethanolamine N-methyltransferase (PEMT) ( 71 ), diacylglycerol kinase (DAGK) (72)(73)(74)(75), lipid phosphate phosphatase (LPP) ( 76 ), diacylglycerol lipase (DAGL) ( 77,78 ), PI synthase ( 79 ), phosphoinositide-3-kinase (PI3K) ( 80,81 ), and PLD ( 82 ) have been reported to be modulated by light. Detailed studies on PI3K signaling are described by Rajala in the thematic review in this series on PI3K in the vertebrate retina.…”

Section: Light Regulation Of Enzymes Related To the Generation Of Secmentioning

confidence: 99%

Lipid second messengers and related enzymes in vertebrate rod outer segments

Giusto

Pasquaré

Salvador

et al. 2010

Journal of Lipid Research

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outer segment of the cell is comprised of a stack of many hundreds of densely packed discs, each of which represents a double layer of infolded plasma membrane. It has been suggested that phospholipid moieties in these membranes are metabolically active and are closely involved in the generation of physiological mediators. Modifi cations in the metabolism of photoreceptor membrane glycerolipids have been linked to the transduction of visual stimuli ( 3 ). Rod outer segment (ROS) membranes are composed of 50% protein and 50% lipid, by weight ( 2 ). Phospholipids and cholesterol represent nearly 90-95% and 4-6% (w/w) of total lipids, respectively. Rhodopsin accounts for at least 80-85% (w/w) of the total proteins ( 4-6 ) in disc ROS membranes. The rest are mainly proteins involved in phototransduction. The composition of mammalian ROS membrane phospholipids indicates that the major phospholipids are phosphatidylethanolamine (PE) and phosphatidylcholine (PC), along with relatively large amounts of phosphatidylserine (PS) (15%). Small amounts (less than 1% each) of sphingomyelin, phosphatidylinositol (PI) and phosphatidic acid (PA) are found in these membranes ( 7-13 ). In vertebrates, cholesterol (exclusively as the free sterol) is the principal neutral lipid, comprising The vertebrate photoreceptor cell is composed of different cellular compartments [outer segment (OS), inner segment (IS), and synaptic terminal (ST)], all of which differ in their lipid and protein content ( 1, 2 ). The photoreceptor is a highly specialized cell that responds to light stimulus and transmits this response to adjoining neurons for ultimate relay to the visual centers of the brain. TheThis work was supported

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“…It has been extensively reported that the activity of enzymes involved in ROS phospholipid turnover such as phospholipase C [15,16], phospholipase A2 [17], phosphatidylethanolamine N-methyltransferase [18], diacylglycerol kinase [19], PAP2 [14], phosphoinositide-3-kinase [20,21], and phospholipase D [22] is modulated by light. This fact and the evidence that light induces a redistribution of proteins involved in phototransduction open an attractive field for the study of PA hydrolysis by LPPs under illumination conditions.…”

Section: Introductionmentioning

confidence: 99%

Involvement of Lysophosphatidic Acid, Sphingosine 1-Phosphate and Ceramide 1-Phosphate in the Metabolization of Phosphatidic Acid by Lipid Phosphate Phosphatases in Bovine Rod Outer Segments

2008

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The aim of the present research was to evaluate the generation of [2-3H]diacylglycerol ([2-3H]DAG) from [2-3H]-Phosphatidic acid ([2-3H]PA) by lipid phosphate phosphatases (LPPs) at different concentrations of lysophosphatidic acid (LPA), sphingosine 1-phosphate (S1P), and ceramide 1-phosphate (C1P) in purified ROS obtained from dark-adapted retinas (DROS) or light-adapted retinas (BLROS) as well as in ROS membrane preparations depleted of soluble and peripheral proteins. Western blot analysis revealed the presence of LPP3 exclusively in all membrane preparations. Immunoblots of entire ROS and depleted ROS did not show dark-light differences in LPP3 levels. LPPs activities were diminished by 53% in BLROS with respect to DROS. The major competitive effect on PA hydrolysis was exerted by LPA and S1P in DROS and by C1P in BLROS. LPPs activities in depleted ROS were similar to the activity observed in entire DROS and BLROS, respectively. LPA, S1P and C1P competed at different extent in depleted DROS and BLROS. Sphingosine and ceramide inhibited LPPs activities in entire and depleted DROS. Ceramide also inhibited LPPs activities in entire and in depleted BLROS. Our findings are indicative of a different degree of competition between PA and LPA, S1P and C1P by LPPs depending on the illumination state of the retina.

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Light Activation of Phosphatidylethanolamine N-Methyltransferase in Rod Outer Segments and its Modulation by Association States of Transducin

Cited by 10 publications

References 38 publications

Diacylglyceride lipase activity in rod outer segments depends on the illumination state of the retina

Diacylglyceride lipase activity in rod outer segments depends on the illumination state of the retina

Lipid second messengers and related enzymes in vertebrate rod outer segments

Involvement of Lysophosphatidic Acid, Sphingosine 1-Phosphate and Ceramide 1-Phosphate in the Metabolization of Phosphatidic Acid by Lipid Phosphate Phosphatases in Bovine Rod Outer Segments

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