title: The ABC of auxin transport: the role of p-glycoproteins in plant development.
abstract: A surprising outcome of the Arabidopsis genome project was the annotation of a large number of sequences encoding members of the ABC transporter superfamily, including 22 genes encoding the p-glycoprotein (PGP) subfamily. As mammalian PGP orthologs are associated with multiple drug resistance, plant PGPs were initially presumed to function in detoxification, but were soon seen to have a developmental role. Here, we summarise recent studies of plant PGPs indicating that PGPs mediate the cellular and long-distance transport of the plant hormone auxin. One class of PGPs, represented by AtPGP1, catalyze auxin export, while another class with at least one member, AtPGP4, appears to function in auxin import. Current models on the physiological role of PGPs, their functional interaction and their involvement in cell-to cell (polar) auxin transport are discussed.
authors.affiliation: Zurich-Basel Plant Science Center, Institute of Plant Biology, University of Zurich, CH-8007 Zurich, Switzerland. markus.geisler@botinst.unizh.ch
authors.forename: Markus
authors.initials: M
authors.lastname: Geisler
authors.forename: Angus S
authors.initials: AS
authors.lastname: Murphy
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000502:physiology*; D018528:ATP-Binding Cassette Transporters / Q000502:physiology*; D017360:Arabidopsis / Q000145:classification / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000502:physiology*; D007210:Indoleacetic Acids / Q000378:metabolism*; D010802:Phylogeny
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D018528:ATP-Binding Cassette Transporters; D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids