title: Molecular determinants of the olfactory receptor Olfr544 activation by azelaic acid.
abstract: The mouse olfactory receptor Olfr544 is expressed in several non-olfactory tissues and has been suggested as a functional receptor regulating different signaling pathways. However, the molecular interaction between Olfr544 and its natural ligand, azelaic acid (AzA), remains poorly characterized, primarily due to difficulties in the heterologous expression of the receptor protein on the cell membrane and lack of entire protein structure. In this report, we describe the molecular determinants of Olfr544 activation by AzA. N-terminal lucy-flag-rho tag ensured the heterologous expression of Olfr544 on the Hana3A cell surface. Molecular modeling and docking combined with mutational analysis identified amino acid residues in the Olfr544 for the interaction with AzA. Our data demonstrated that the Y109 residue in transmembrane helix 3 forms a hydrogen bond with AzA, which is crucial for the receptor-ligand interaction and activation. Y109 is required for the Olfr544 activation by AzA which, in turn, stimulates the Olfr544-dependent CREB-PGC-1α signaling axis and is followed by the induction of mitochondrial biogenesis in Olfr544 wild-type transfected Hana3A cells, but not in mock or Y109A mutant transfected cells. Collectively, these data indicated that a hydrogen bond between Y109 residue and AzA is a major determinant of the Olfr544-AzA interaction and activation.
authors.affiliation: Department of Biotechnology, BK21-PLUS, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Trung Thanh
authors.initials: TT
authors.lastname: Thach
authors.affiliation: Department of Biotechnology, BK21-PLUS, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea.
authors.forename: Yu-Jung
authors.initials: YJ
authors.lastname: Hong
authors.affiliation: Department of Biological Sciences, Sungkyunkwan University, Suwon 16419, Republic of Korea.
authors.forename: Sangho
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Biotechnology, BK21-PLUS, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Republic of Korea. Electronic address: junelee@korea.ac.kr.
authors.forename: Sung-Joon
authors.initials: SJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D002460:Cell Line; D003998:Dicarboxylic Acids / Q000378:metabolism*; D006801:Humans; D006860:Hydrogen Bonding; D051379:Mice; D062105:Molecular Docking Simulation; D017354:Point Mutation; D011485:Protein Binding; D011487:Protein Conformation; D018035:Receptors, Odorant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D003998:Dicarboxylic Acids; D018035:Receptors, Odorant; C000592905:Or55b4 protein, mouse; C010038:azelaic acid
keywords: Activation; Azelaic acid; Interaction; Olfactory receptor; Olfr544