title: Conserved dimeric subunit stoichiometry of SLC26 multifunctional anion exchangers.
abstract: The SLC26 gene family encodes multifunctional transport proteins in numerous tissues and organs. Some paralogs function as anion exchangers, others as anion channels, and one, prestin (SLC26A5), represents a membrane-bound motor protein in outer hair cells of the inner ear. At present, little is known about the molecular basis of this functional diversity. We studied the subunit stoichiometry of one bacterial, one teleost, and two mammalian SLC26 isoforms expressed in Xenopus laevis oocytes or in mammalian cells using blue native PAGE and chemical cross-linking. All tested SLC26s are assembled as dimers composed of two identical subunits. Co-expression of two mutant prestins with distinct voltage-dependent capacitances results in motor proteins with novel electrical properties, indicating that the two subunits do not function independently. Our results indicate that an evolutionarily conserved dimeric quaternary structure represents the native and functional state of SLC26 transporters.
authors: Abteilung Molekulare Pharmakologie, Rheinisch-Westfälische Technische Hochschule Aachen University, Wendlingweg 2, Aachen 52074, Germany.
authors: Silvia
authors: S
authors: Detro-Dassen
authors: Michael
authors: M
authors: Schänzler
authors: Heike
authors: H
authors: Lauks
authors: Ina
authors: I
authors: Martin
authors: Sonja Meyer
authors: SM
authors: zu Berstenhorst
authors: Doreen
authors: D
authors: Nothmann
authors: Delany
authors: D
authors: Torres-Salazar
authors: Patricia
authors: P
authors: Hidalgo
authors: Günther
authors: G
authors: Schmalzing
authors: Christoph
authors: C
authors: Fahlke
mesh_terms: D000818:Animals; D027321:Anion Transport Proteins / Q000737:chemistry* / Q000502:physiology; D018118:Chloride Channels / Q000502:physiology; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D051381:Rats; D000076988:Sulfate Transporters; D014982:Xenopus laevis
chemical_list: D027321:Anion Transport Proteins; C086321:CLC-1 channel; D018118:Chloride Channels; C473560:SLC26A1 protein, human; C498719:SLC26A5 protein, human; D000076988:Sulfate Transporters