title: Diacylglycerol regulates the plasma membrane calcium pump from human erythrocytes by direct interaction.
abstract: The plasma membrane Ca(2+)-ATPase (PMCA) plays a key role in the regulation of the intracellular Ca(2+) concentration. Ethanol stimulates this Ca(2+) pump in an isoform-specific manner. On search for a physiological molecule that could mimic the effect of ethanol, we have previously demonstrated that some sphingolipids containing free "hydroxyl" groups, like ceramide, are able to stimulate the PMCA. Since diacylglycerol (DAG) structurally shares some characteristics with ceramide, we evaluate its effect on the PMCA. We demonstrated that DAG is a potent stimulator of this enzyme. The activation induced is additive to that produced by calmodulin, protein-kinase C and ethanol, which implies that DAG interacts with the PMCA through a different mechanism. Additionally, by different fluorescent approaches, we demonstrated a direct binding between PMCA and DAG. The results obtained in this work strongly suggest that DAG is a novel effector of the PMCA, acting by a direct interaction.
authors.affiliation: Instituto de Biología Experimental (IBE), Facultad de Ciencias, Universidad Central de Venezuela, Caracas, Venezuela.
authors.forename: Maria C
authors.initials: MC
authors.lastname: Pérez-Gordones
authors.forename: Miguel R
authors.initials: MR
authors.lastname: Lugo
authors.forename: Moraima
authors.initials: M
authors.lastname: Winkler
authors.forename: Vincenza
authors.initials: V
authors.lastname: Cervino
authors.forename: Gustavo
authors.initials: G
authors.lastname: Benaim
mesh_terms: D002118:Calcium / Q000737:chemistry* / Q000378:metabolism; D002147:Calmodulin / Q000737:chemistry / Q000378:metabolism; D002518:Ceramides / Q000737:chemistry / Q000378:metabolism; D004075:Diglycerides / Q000737:chemistry* / Q000378:metabolism; D004789:Enzyme Activation / Q000502:physiology; D004910:Erythrocyte Membrane / Q000201:enzymology*; D000431:Ethanol / Q000737:chemistry / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000737:chemistry / Q000378:metabolism; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000737:chemistry* / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D011493:Protein Kinase C / Q000737:chemistry / Q000378:metabolism
chemical_list: D002147:Calmodulin; D002518:Ceramides; D004075:Diglycerides; D007527:Isoenzymes; D000431:Ethanol; D011493:Protein Kinase C; D053499:Plasma Membrane Calcium-Transporting ATPases; D002118:Calcium