1
|
Ikegami K, de March CA, Nagai MH, Ghosh S, Do M, Sharma R, Bruguera ES, Lu YE, Fukutani Y, Vaidehi N, Yohda M, Matsunami H. Structural instability and divergence from conserved residues underlie intracellular retention of mammalian odorant receptors. Proc Natl Acad Sci U S A 2020; 117:2957-2967. [PMID: 31974307 PMCID: PMC7022149 DOI: 10.1073/pnas.1915520117] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mammalian odorant receptors are a diverse and rapidly evolving set of G protein-coupled receptors expressed in olfactory cilia membranes. Most odorant receptors show little to no cell surface expression in nonolfactory cells due to endoplasmic reticulum retention, which has slowed down biochemical studies. Here we provide evidence that structural instability and divergence from conserved residues of individual odorant receptors underlie intracellular retention using a combination of large-scale screening of odorant receptors cell surface expression in heterologous cells, point mutations, structural modeling, and machine learning techniques. We demonstrate the importance of conserved residues by synthesizing consensus odorant receptors that show high levels of cell surface expression similar to conventional G protein-coupled receptors. Furthermore, we associate in silico structural instability with poor cell surface expression using molecular dynamics simulations. We propose an enhanced evolutionary capacitance of olfactory sensory neurons that enable the functional expression of odorant receptors with cryptic mutations.
Collapse
Affiliation(s)
- Kentaro Ikegami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Claire A de March
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
| | - Maira H Nagai
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
- Department of Biochemistry, Universidade de Sao Paulo, Sao Paulo, 05508-000, Brazil
| | - Soumadwip Ghosh
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Matthew Do
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
| | - Ruchira Sharma
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
| | - Elise S Bruguera
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
| | - Yueyang Eric Lu
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
| | - Yosuke Fukutani
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Nagarajan Vaidehi
- Department of Computational and Quantitative Medicine, Beckman Research Institute of the City of Hope, Duarte, CA 91010
| | - Masafumi Yohda
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC 27710;
- Department of Neurobiology, Duke Institute for Brain Sciences, Duke University, Durham, NC 27710
| |
Collapse
|
2
|
Sharma R, Ishimaru Y, Davison I, Ikegami K, Chien MS, You H, Chi Q, Kubota M, Yohda M, Ehlers M, Matsunami H. Olfactory receptor accessory proteins play crucial roles in receptor function and gene choice. eLife 2017; 6. [PMID: 28262096 PMCID: PMC5362263 DOI: 10.7554/elife.21895] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 02/16/2017] [Indexed: 11/13/2022] Open
Abstract
Each of the olfactory sensory neurons (OSNs) chooses to express a single G protein-coupled olfactory receptor (OR) from a pool of hundreds. Here, we show the receptor transporting protein (RTP) family members play a dual role in both normal OR trafficking and determining OR gene choice probabilities. Rtp1 and Rtp2 double knockout mice (RTP1,2DKO) show OR trafficking defects and decreased OSN activation. Surprisingly, we discovered a small subset of the ORs are expressed in larger numbers of OSNs despite the presence of fewer total OSNs in RTP1,2DKO. Unlike typical ORs, some overrepresented ORs show robust cell surface expression in heterologous cells without the co-expression of RTPs. We present a model in which developing OSNs exhibit unstable OR expression until they choose to express an OR that exits the ER or undergo cell death. Our study sheds light on the new link between OR protein trafficking and OR transcriptional regulation.
Collapse
Affiliation(s)
- Ruchira Sharma
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States
| | - Yoshiro Ishimaru
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States.,Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ian Davison
- Department of Biology, Boston University, Boston, United States
| | - Kentaro Ikegami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States.,Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Ming-Shan Chien
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States
| | - Helena You
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States
| | - Quiyi Chi
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States
| | - Momoka Kubota
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States
| | - Masafumi Yohda
- Tokyo University of Agriculture and Technology, Tokyo, Japan
| | - Michael Ehlers
- Department of Neurobiology, Duke University Medical Center, Durham, United States.,Biogen Inc, Cambridge, United States
| | - Hiroaki Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, United States.,Department of Neurobiology, Duke University Medical Center, Durham, United States.,Duke Institute for Brain Sciences, Durham, United States
| |
Collapse
|