The chloride pump: a Cl(-)-translocating P-type ATPase.
Three widely documented mechanisms of chloride transport across plasma membranes are anion-coupled antiport, sodium-coupled symport, and an electrochemical coupling process. No direct genetic evidence has yet been provided for primary active chloride transport despite numerous reports of cellular Cl(-)-stimulated adenosine triphosphate (ATP)ases coexisting in the same tissue with uphill chloride transport that could not be accounted for by the three common chloride transport processes. Cl(-)-stimulated ATPases are a common property of practically all biological cells, with the major location being of mitochondrial origin. It also appears that plasma membranes are sites of Cl(-)-stimulated ATPase activity. Recent studies of Cl(-)-stimulated ATPase activity and chloride transport in the same membrane system, including liposomes, suggest a mediation by the ATPase in net movement of chloride up its electrochemical gradient across plasma membranes. Further studies, especially from a molecular biological perspective, are required to confirm a direct transport role to plasma membrane-localized Cl(-)-stimulated ATPases.
Gerencser
G A
GA
Department of Physiology, College of Medicine, University of Florida, Gainesville 32610-0274, USA.
D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000145:classification / Q000502:physiology*; D000818:Animals; D027321:Anion Transport Proteins; D000838:Anions / Q000378:metabolism; D001048:Aplysia / Q000033:anatomy & histology; D001692:Biological Transport; D006801:Humans; D007422:Intestines / Q000502:physiology; D007700:Kinetics; D008081:Liposomes / Q000737:chemistry; D008970:Molecular Weight; D010766:Phosphorylation; D013438:Sulfhydryl Compounds / Q000378:metabolism; D014018:Tissue Distribution
D027321:Anion Transport Proteins; D000838:Anions; D008081:Liposomes; D013438:Sulfhydryl Compounds; D000251:Adenosine Triphosphatases; C031652:anion-sensitive ATPases