title: The yeast Ste2p G protein-coupled receptor dimerizes on the cell plasma membrane.
abstract: Dimerization of G protein-coupled receptors (GPCR) may play an important role in maturation, internalization, signaling and/or pharmacology of these receptors. However, the location where dimerization occurs is still under debate. In our study, variants of Ste2p, a yeast mating pheromone GPCR, were tagged with split EGFP (enhanced green fluorescent protein) fragments inserted between transmembrane domain seven and the C-terminus or appended to the C-terminus. Bimolecular Fluorescence Complementation (BiFC) assay was used to determine where receptor dimerization occurred during protein trafficking by monitoring generation of EGFP fluorescence, which occurred upon GPCR dimerization. Our results suggest that these tagged receptors traffic to the membrane as monomers, undergo dimerization or higher ordered oligomerization predominantly on the plasma membrane, and are internalized as dimers/oligomers. This study is the first to provide direct in vivo visualization of GPCR dimerization/oligomerization, during trafficking to and from the plasma membrane.
authors.affiliation: Department of Biological Sciences, Middle East Technical University, Universiteler Mah. Dumlupinar Blv. No: 1, 06800 Cankaya, Ankara, Turkey; Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States.
authors.forename: Orkun
authors.initials: O
authors.lastname: Cevheroğlu
authors.affiliation: Department of Biological Sciences, Middle East Technical University, Universiteler Mah. Dumlupinar Blv. No: 1, 06800 Cankaya, Ankara, Turkey.
authors.forename: Gözde
authors.initials: G
authors.lastname: Kumaş
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States.
authors.forename: Melinda
authors.initials: M
authors.lastname: Hauser
authors.affiliation: Department of Microbiology, University of Tennessee, Knoxville, TN 37996, United States.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Becker
authors.affiliation: Department of Biological Sciences, Middle East Technical University, Universiteler Mah. Dumlupinar Blv. No: 1, 06800 Cankaya, Ankara, Turkey. Electronic address: cson@metu.edu.tr.
authors.forename: Çağdaş D
authors.initials: ÇD
authors.lastname: Son
mesh_terms: D002462:Cell Membrane / Q000737:chemistry*; D055503:Protein Multimerization; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry*; D051964:Receptors, Mating Factor / Q000737:chemistry*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry*
chemical_list: D043562:Receptors, G-Protein-Coupled; D051964:Receptors, Mating Factor; C498031:STE2 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins
keywords: Bimolecular fluorescence complementation assay (BiFC); GPCR dimerization; GPCR traffic; Split EGFP; Ste2p