title: Transport of leukotriene C4 by a cysteine-less multidrug resistance protein 1 (MRP1).
abstract: Overexpression of multidrug resistance protein 1 (MRP1), an ATP-binding cassette protein, causes multidrug resistance. We developed a functional cysteine-less version of MRP1 that provides a framework for detailed biochemical and biophysical studies. The 18 Cys residues of a truncated MRP1 (tMRP1; lacking the first multispanning transmembrane domain) were replaced with Ala to generate Cys-less tMRP1 (CL tMRP1). CL tMRP1 expressed in Saccharomyces cerevisiae membranes displayed high-affinity ATP-dependent transport of the MRP1 substrate leukotriene C4. Compared with full-length MRP1, the K m for leukotriene C4 transport by CL tMRP1 was increased approximately 3-fold, while V max was not affected. Thus a functional CL tMRP1 can be expressed using a low-cost and rapid-generation yeast expression system. This Cys-less protein can be used for biochemical, spectroscopic and structural studies to elucidate the mechanism of drug transport by MRP1.
authors.affiliation: Membrane Protein Laboratory, Sealy Center for Structural Biology and Department of Physiology and Biophysics, The University of Texas Medical Branch, Galveston, TX 77555-0437, USA.
authors.forename: Sung H
authors.initials: SH
authors.lastname: Lee
authors.forename: Guillermo A
authors.initials: GA
authors.lastname: Altenberg
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000235:genetics / Q000378:metabolism*; D001692:Biological Transport; D017997:Leukotriene C4 / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D011994:Recombinant Proteins; D017997:Leukotriene C4