Role of the protein kinase C signaling pathway in high-density lipoprotein receptor-mediated efflux of intracellular cholesterol.
These studies provide evidence that binding of HDL3 to the HDL receptor stimulates translocation and efflux of intracellular cholesterol through mechanisms involving the activation of protein kinase C. This conclusion is supported by data demonstrating that HDL is able to increase cell diacylglycerol levels and activate protein kinase C. Sphingosine, a protein kinase C inhibitor, was able to inhibit HDL3-mediated cholesterol translocation and efflux, further suggesting a role for protein kinase C in HDL receptor-dependent cholesterol efflux. Inhibition of HDL-mediated diacylglycerol formation by pertussis toxin suggests the possible involvement of a G protein-activated phospholipase. Further studies are needed to understand how activation of protein kinase C promotes cholesterol translocation and to identify the target proteins for protein kinase C phosphorylation.
Mendez
A J
AJ
Department of Medicine, University of Washington, Seattle 98195.
Oram
J F
JF
Bierman
E L
EL
D001693:Biological Transport, Active; D002352:Carrier Proteins; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism*; D004075:Diglycerides / Q000378:metabolism; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism; D053440:Lipoproteins, HDL3; D008954:Models, Biological; D011493:Protein Kinase C / Q000378:metabolism*; D016601:RNA-Binding Proteins; D011956:Receptors, Cell Surface / Q000378:metabolism*; D018110:Receptors, Lipoprotein; D015398:Signal Transduction / Q000502:physiology
D002352:Carrier Proteins; D004075:Diglycerides; D008075:Lipoproteins, HDL; D053440:Lipoproteins, HDL3; D016601:RNA-Binding Proteins; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein; C031616:high density lipoprotein receptors; C075197:high density lipoprotein binding protein; D002784:Cholesterol; D011493:Protein Kinase C