title: RTP family members induce functional expression of mammalian odorant receptors.
abstract: Transport of G protein-coupled receptors (GPCRs) to the cell surface membrane is critical in order for the receptors to recognize their ligands. However, mammalian GPCR odorant receptors (ORs), when heterologously expressed in cells, are poorly expressed on the cell surface. Here we show that the transmembrane proteins RTP1 and RTP2 promote functional cell surface expression of ORs expressed in HEK293T cells. Genes encoding these proteins are expressed specifically in olfactory neurons. These proteins are associated with OR proteins and enhance the OR responses to odorants. Similar although weaker effects were seen with a third protein, REEP1. These findings suggest that RTP1 and RTP2 in particular play significant roles in the translocation of ORs to the plasma membrane as well as in the functioning of ORs. We have used this approach to identify active odorant ligands for ORs, providing a platform for screening the chemical selectivity of the large OR family.
authors.affiliation: Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham, NC 27710, USA.
authors.forename: Harumi
authors.initials: H
authors.lastname: Saito
authors.forename: Momoka
authors.initials: M
authors.lastname: Kubota
authors.forename: Richard W
authors.initials: RW
authors.lastname: Roberts
authors.forename: Qiuyi
authors.initials: Q
authors.lastname: Chi
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsunami
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism*; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D004353:Drug Evaluation, Preclinical; D005786:Gene Expression Regulation / Q000502:physiology; D006801:Humans; D008024:Ligands; D008322:Mammals / Q000033:anatomy & histology / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D018034:Olfactory Receptor Neurons / Q000187:drug effects / Q000378:metabolism*; D010802:Phylogeny; D021381:Protein Transport / Q000502:physiology; D018035:Receptors, Odorant / Q000187:drug effects / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D012903:Smell / Q000502:physiology
chemical_list: D018076:DNA, Complementary; D008024:Ligands; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C495318:REEP1 protein, human; C495316:RTP1 protein, human; C495317:RTP2 protein, human; D018035:Receptors, Odorant