title: Palmitoyl-CoA stimulates cellular uptake and plasma membrane binding of carnitine.
abstract: Carnitine cellular uptake and plasma membrane binding was investigated in S49 lymphoma cells. Palmitoyl-CoA was found to increase membrane binding of carnitine from 506 +/- 48 to 8,690 +/- 235 pmol/mg membrane protein. Palmitate and CoA acted synergistically and increased carnitine binding to plasma membranes but could not replace palmitoyl-CoA. The effect of palmitoyl-CoA on membrane binding of carnitine was maximal at 10 microM and required the presence of ATP. Palmitoyl-CoA increased the cellular uptake rate of carnitine from 181 +/- 5 to 884 +/- 25 amol/cell and h-1. We conclude that palmitoyl-CoA is a major regulator of cellular uptake of carnitine and, based on quantitative estimations, that the carnitine carrier binds more than one carnitine molecule.
authors.affiliation: Department of Allergology, Sahlgren's University Hospital, Göteborg, Sweden.
authors.forename: B
authors.initials: B
authors.lastname: Gustafson
authors.forename: L A
authors.initials: LA
authors.lastname: Ransnäs
mesh_terms: D000818:Animals; D001665:Binding Sites; D001693:Biological Transport, Active / Q000187:drug effects; D002331:Carnitine / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects* / Q000378:metabolism*; D051379:Mice; D010171:Palmitoyl Coenzyme A / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D010171:Palmitoyl Coenzyme A; D002331:Carnitine