title: Long-range coupling between the extracellular gates and the intracellular ATP binding domains of multidrug resistance protein pumps and cystic fibrosis transmembrane conductance regulator channels.
abstract: The ABCC transporter subfamily includes pumps, the long and short multidrug resistance proteins (MRPs), and an ATP-gated anion channel, the cystic fibrosis transmembrane conductance regulator (CFTR). We show that despite their thermodynamic differences, these ABCC transporter subtypes use broadly similar mechanisms to couple their extracellular gates to the ATP occupancies of their cytosolic nucleotide binding domains. A conserved extracellular phenylalanine at this gate was a prime location for producing gain of function (GOF) mutants of a long MRP in yeast (Ycf1p cadmium transporter), a short yeast MRP (Yor1p oligomycin exporter), and human CFTR channels. Extracellular gate mutations rescued ATP binding mutants of the yeast MRPs and CFTR by increasing ATP sensitivity. Control ATPase-defective MRP mutants could not be rescued by this mechanism. A CFTR double mutant with an extracellular gate mutation plus a cytosolic GOF mutation was highly active (single-channel open probability >0.3) in the absence of ATP and protein kinase A, each normally required for CFTR activity. We conclude that all 3 ABCC transporter subtypes use similar mechanisms to couple their extracellular gates to ATP occupancy, and highly active CFTR channels that bypass defects in ATP binding or phosphorylation can be produced.
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Shipeng
authors.initials: S
authors.lastname: Wei
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Roessler
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Mert
authors.initials: M
authors.lastname: Icyuz
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Chauvet
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: Binli
authors.initials: B
authors.lastname: Tao
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA.
authors.forename: John L
authors.initials: JL
authors.lastname: Hartman
authors.affiliation: *Department of Cell, Developmental, and Integrative Biology, Department of Genetics, and Department of Neurobiology, Gregory Fleming James Cystic Fibrosis Research Center, University of Alabama at Birmingham, Birmingham, Alabama, USA klkirk@uab.edu.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Kirk
mesh_terms: D018435:ATP Binding Cassette Transporter, Subfamily B / Q000235:genetics / Q000378:metabolism*; D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D015640:Ion Channel Gating / Q000235:genetics; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation / Q000235:genetics; D011485:Protein Binding / Q000235:genetics*; D017434:Protein Structure, Tertiary
chemical_list: D018435:ATP Binding Cassette Transporter, Subfamily B; C505032:CFTR protein, human; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D000255:Adenosine Triphosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D000251:Adenosine Triphosphatases
keywords: ABC transporter; allostery; ion channel; phosphorylation