title: Current advances on ABC drug transporters in fish.
abstract: Most members of the large ATP-binding cassette (ABC) gene family are transporters involved in substrate translocation across biological membranes. In eukaryotes, ABC proteins functioning as drug transporters are located in the plasma membrane and mediate the cellular efflux of a wide range of organic chemicals, with some transporters also transporting certain metals. As the enhanced expression of ABC drug transporters can confer multidrug resistance (MDR) to cancers and multixenobiotic resistance (MXR) to organisms from polluted habitats, these ABC family members are also referred to as MDR or MXR proteins. In mammals, ABC drug transporters show predominant expression in tissues involved in excretion or constituting internal or external body boundaries, where they facilitate the excretion of chemicals and their metabolites, and limit chemical uptake and penetration into "sanctuary" sites of the body. Available knowledge about ABC proteins is still limited in teleost fish, a large vertebrate group of high ecological and economic importance. Using transport activity measurements and immunochemical approaches, early studies demonstrated similarities in the tissue distribution of ABC drug transporters between teleosts and mammals, suggesting conserved roles of the transporters in the biochemical defence against toxicants. Recently, the availability of teleost genome assemblies has stimulated studies of the ABC family in this taxon. This review summarises the current knowledge regarding the genetics, functional properties, physiological function, and ecotoxicological relevance of teleostean ABC transporters. The available literature is reviewed with emphasis on recent studies addressing the tissue distribution, substrate spectrum, regulation, physiological function and phylogenetic origin of teleostean ABC transporters.
authors.affiliation: Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, 04318 Leipzig, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Luckenbach
authors.affiliation: Department of Environmental Toxicology, Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland; Department of Environmental Systems Sciences, ETH Zürich, Institute of Biogeochemistry and Pollutant Dynamics, 8092 Zürich, Switzerland.
authors.forename: Stephan
authors.initials: S
authors.lastname: Fischer
authors.affiliation: Institute of Aquaculture, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, Scotland, UK. Electronic address: armin.sturm@stir.ac.uk.
authors.forename: Armin
authors.initials: A
authors.lastname: Sturm
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D018432:Drug Resistance, Multiple / Q000235:genetics; D005399:Fishes / Q000235:genetics* / Q000378:metabolism*; D006801:Humans; D010802:Phylogeny; D014018:Tissue Distribution / Q000235:genetics
chemical_list: D018528:ATP-Binding Cassette Transporters
keywords: ABC gene family; Biochemical defence; Fish; Pollutant; Teleost; Transport; Xenobiotic