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Wu H, Hoare BL, Handley TNG, Akhter Hossain M, Bathgate RAD. Development of a synthetic relaxin-3/INSL5 chimeric peptide ligand for NanoBiT complementation binding assays. Biochem Pharmacol 2024; 224:116238. [PMID: 38677442 DOI: 10.1016/j.bcp.2024.116238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2024] [Revised: 04/09/2024] [Accepted: 04/25/2024] [Indexed: 04/29/2024]
Abstract
INSL5 and relaxin-3 are relaxin family peptides with important roles in gut and brain function, respectively. They mediate their actions through the class A GPCRs RXFP4 and RXFP3. RXFP4 has been proposed to be a therapeutic target for colon motility disorders whereas RXFP3 targeting could be effective for neurological conditions such as anxiety. Validation of these targets has been limited by the lack of specific ligands and the availability of robust ligand-binding assays for their development. In this study, we have utilized NanoBiT complementation to develop a SmBiT-conjugated tracer for use with LgBiT-fused RXFP3 and RXFP4. The low affinity between LgBiT:SmBiT should result in a low non-specific luminescence signal and enable the quantification of binding without the tedious separation of non-bound ligands. We used solid-phase peptide synthesis to produce a SmBiT-labelled RXFP3/4 agonist, R3/I5, where SmBiT was conjugated to the B-chain N-terminus via a PEG12 linker. Both SmBiT-R3/I5 and R3/I5 were synthesized and purified in high purity and yield. Stable HEK293T cell lines expressing LgBiT-RXFP3 and LgBiT-RXFP4 were produced and demonstrated normal signaling in response to the synthetic R3/I5 peptide. Binding was first characterized in whole-cell binding kinetic assays validating that the SmBiT-R3/I5 bound to both cell lines with nanomolar affinity with minimal non-specific binding without bound and free SmBiT-R3/I5 separation. We then optimized membrane binding assays, demonstrating easy and robust analysis of both saturation and competition binding from frozen membranes. These assays therefore provide an appropriate rigorous binding assay for the high-throughput analysis of RXFP3 and RXFP4 ligands.
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Affiliation(s)
- Hongkang Wu
- The Florey, University of Melbourne, Victoria, Australia
| | | | | | - Mohammed Akhter Hossain
- The Florey, University of Melbourne, Victoria, Australia; School of Chemistry, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
| | - Ross A D Bathgate
- The Florey, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
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2
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Andrews A, Cottrell E, Maharaj A, Ladha T, Williams J, Schilbach K, Kaisinger LR, Perry JRB, Metherell LA, McCormick PJ, Storr HL. Characterization of dominant-negative growth hormone receptor variants reveals a potential therapeutic target for short stature. Eur J Endocrinol 2023; 188:353-365. [PMID: 36943306 DOI: 10.1093/ejendo/lvad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 03/07/2023] [Accepted: 03/13/2023] [Indexed: 03/23/2023]
Abstract
OBJECTIVE Growth hormone insensitivity (GHI) encompasses growth restriction, normal/elevated growth hormone (GH), and low insulin-like growth factor I (IGF1). "Nonclassical" GHI is poorly characterized and is rarely caused by heterozygous dominant-negative (DN) variants located in the intracellular or transmembrane domains of the GH receptor (GHR). We sought to determine the molecular mechanisms underpinning the growth restriction in 2 GHI cases. METHODS AND DESIGN A custom-made genetic investigative pipeline was exploited to identify the genetic cause of growth restriction in patients with GHI. Nanoluc binary technology (NanoBiT), in vitro splicing assays, western blotting, and flow cytometry, characterized the novel GHR variants. RESULTS Novel heterozygous GHR variants were identified in 2 unrelated patients with GHI. In vitro splicing assays indicated both variants activated the same alternative splice acceptor site resulting in aberrant splicing and exclusion of 26 base pairs of GHR exon 9. The GHR variants produced truncated receptors and impaired GH-induced GHR signaling. NanoBiT complementation and flow cytometry showed increased cell surface expression of variant GHR homo/heterodimers compared to wild-type (WT) homodimers and increased recombinant human GH binding to variant GHR homo/heterodimers and GH binding protein (GHBP) cleaved from the variant GHRs. The findings demonstrated increased variant GHR dimers and GHBP with resultant GH sequestration. CONCLUSION We identified and characterized 2 novel, naturally occurring truncated GHR gene variants. Intriguingly, these DN GHR variants act via the same cryptic splice acceptor site, highlighting impairing GH binding to excess GHBP as a potential therapeutic approach.
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Affiliation(s)
- Afiya Andrews
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Emily Cottrell
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Avinaash Maharaj
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Tasneem Ladha
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Jack Williams
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Katharina Schilbach
- Endocrine Laboratory, Medizinische Klinik und Poliklinik IV, Klinikum der Universität München, Munich, Germany
| | - Lena R Kaisinger
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge CB2 0QQ, United Kingdom
| | - John R B Perry
- MRC Epidemiology Unit, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge CB2 0QQ, United Kingdom
- Metabolic Research Laboratory, Wellcome-MRC Institute of Metabolic Science, University of Cambridge School of Clinical Medicine, Cambridge CB2 0QQ, United Kingdom
| | - Louise A Metherell
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Peter J McCormick
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
| | - Helen L Storr
- Centre for Endocrinology, William Harvey Research Institute, Barts and The London School of Medicine, Queen Mary University London, London, United Kingdom
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3
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Li HZ, Shao XX, Wang YF, Liu YL, Xu ZG, Guo ZY. LEAP2 is a more conserved ligand than ghrelin for fish GHSRs. Biochimie 2023; 209:10-19. [PMID: 36669723 DOI: 10.1016/j.biochi.2023.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 12/10/2022] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Recently, liver-expressed antimicrobial peptide 2 (LEAP2) was identified as an endogenous antagonist and an inverse agonist of the ghrelin receptor GHSR. However, its functions in lower vertebrates are not well understood. Our recent study demonstrated that both LEAP2 and ghrelin are functional towards a fish GHSR from Latimeria chalumnae, an extant coelacanth believed to be one of the closest ancestors of tetrapods. However, amino acid sequence alignment identified that the 6.58 position (Ballesteros-Weinstein numbering system) of most fish GHSRs are not occupied by an aromatic Phe residue, which is absolutely conserved in all known GHSRs from amphibians to mammals, and is responsible for human GHSR binding to its agonist, ghrelin. To test whether these unusual fish receptors are functional, we studied the ligand binding properties of three representative fish GHSRs, two from Danio rerio (zebrafish) and one from Larimichthys crocea (large yellow croaker). After overexpression in human embryonic kidney 293T cells, the three fish GHSRs retained normal binding to all tested LEAP2s, except for a second LEAP2 from L. crocea. However, they displayed almost no binding to all chemically synthesized n-octanoylated ghrelins, despite these ghrelins all retaining normal function towards human and coelacanth GHSRs. Thus, it seems that LEAP2 is a more conserved ligand than ghrelin towards fish GHSRs. Our results not only provided new insights into the interaction mechanism of GHSRs with LEAP2s and ghrelins, but also shed new light on the functions of LEAP2 and ghrelin in different fish species.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Fen Wang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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4
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Zhang CH, Shao XX, Wang XB, Shou LL, Liu YL, Xu ZG, Guo ZY. Development of a general bioluminescent activity assay for peptide ligases. FEBS J 2022; 289:5241-5258. [PMID: 35239242 DOI: 10.1111/febs.16416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 01/13/2022] [Accepted: 02/28/2022] [Indexed: 11/28/2022]
Abstract
In recent years, some peptide ligases have been identified, such as bacterial sortases and certain plant asparaginyl or prolyl endopeptidases. Peptide ligases have wide applications in protein labelling and cyclic peptide synthesis. To characterize various known peptide ligases or identify new ones, we propose a general bioluminescent activity assay via the genetic fusion of a recognition motif of peptide ligase(s) to the C-terminus of an inactive large NanoLuc fragment (LgBiT) and the chemical introduction of a nucleophilic motif preferred by the peptide ligase(s) to the N-terminus of the low-affinity SmBiT complementation tag. After the inactive ligation version LgBiT protein was ligated with the low-affinity ligation version SmBiT tag by the expected peptide ligase(s), its luciferase activity would be restored and could be quantified sensitively according to the measured bioluminescence. In the present study, we first validated the bioluminescent activity assay using bacterial sortase A and plant-derived butelase-1. Subsequently, we screened novel peptide ligases from crude extracts of selected plants using two LgBiT-SmBiT ligation pairs. Among 80 common higher plants, we identified that five of them likely express asparaginyl endopeptidase-type peptide ligase and four of them likely express prolyl endopeptidase-type peptide ligase, suggesting that peptide ligases are not so rare in higher plants and more of them await discovery. The present bioluminescent activity assay is ultrasensitive, convenient for use, and resistant to protease interference, and thus would have wide applications for characterizing known peptide ligases or screening new ones from various sources in future studies.
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Affiliation(s)
- Cong-Hui Zhang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xin-Bo Wang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Li-Li Shou
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
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5
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Liu YL, Guo ZY. The NanoBiT-Based Homogenous Ligand-Receptor Binding Assay. Methods Mol Biol 2022; 2525:139-153. [PMID: 35836065 DOI: 10.1007/978-1-0716-2473-9_10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
NanoLuc Binary Technology (NanoBiT) was recently developed by Promega, based on a large NanoLuc fragment (LgBiT) and two small complementation tags, the low-affinity SmBiT tag and the high-affinity HiBiT tag. In recent studies, we applied NanoBiT to ligand-binding assays of some G protein-coupled receptors via genetic fusion of a secretory LgBiT (sLgBiT) to the extracellular N-terminus of the receptors and covalent attachment of the low-affinity SmBiT tag to an appropriate position of their peptide ligands. The NanoBiT-based homogenous ligand-receptor binding assay is convenient for use and suitable for both the wild-type and mutant receptors, representing a novel tool for interaction mechanism studies of these receptors with their ligands. In the present chapter, we provide detailed protocols for setting up the NanoBiT-based homogenous binding assay using growth hormone secretagogue receptor type 1a (GHSR1a) and its endogenous agonist and antagonist as a representative model system.
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Affiliation(s)
- Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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6
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Li HZ, Li N, Shao XX, Liu YL, Xu ZG, Guo ZY. Hydrophobic interactions of relaxin family peptide receptor 3 with ligands identified using a NanoBiT-based binding assay. Biochimie 2020; 177:117-126. [PMID: 32810565 DOI: 10.1016/j.biochi.2020.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 06/23/2020] [Accepted: 08/12/2020] [Indexed: 10/23/2022]
Abstract
Relaxin family peptide receptor 3 (RXFP3) is a G protein-coupled receptor implicated in the regulation of food intake and stress response upon activation by the neuropeptide relaxin-3. In recent studies, interactions of RXFP3 with some natural or synthetic ligands have been investigated. In the present study, we identified the hydrophobic interactions of human RXFP3 with the chimeric agonist R3/I5 and the chimeric antagonist R3(ΔB23-27)R/I5 using a newly developed NanoBiT-based homogenous binding assay. We first demonstrated that the conserved large aliphatic B15Ile and B19Ile were important for the binding of the agonist and antagonist to RXFP3, because alanine replacement significantly decreased their receptor-binding potency. Thereafter, we demonstrated that the conserved large aliphatic Leu246 and Leu248 in extracellular loop 2 were important for RXFP3 binding to the agonist and antagonist, because alanine replacement significantly decreased the binding affinity of RXFP3 for both ligands. Finally, we deduced probable hydrophobic interactions based on the ability of RXFP3 mutants to distinguish the wild-type and mutant ligands: Leu246 of RXFP3 interacted with B15Ile of both ligands, while Leu248 of RXFP3 interacted with both B15Ile and B19Ile of the agonist and antagonist. The present results not only provided new insights into the interaction mechanism of RXFP3 with agonists and antagonists, but also demonstrated usefulness of the NanoBiT-based homogenous binding assay to study the interaction mechanism of certain receptors with their ligands.
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Affiliation(s)
- Hao-Zheng Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ning Li
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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7
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Song X, Yu Y, Shen C, Wang Y, Wang N. Dimerization/oligomerization of the extracellular domain of the GLP-1 receptor and the negative cooperativity in its ligand binding revealed by the improved NanoBiT. FASEB J 2020; 34:4348-4368. [PMID: 31970836 DOI: 10.1096/fj.201902007r] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 12/15/2019] [Accepted: 01/12/2020] [Indexed: 12/13/2022]
Abstract
The glucagon-like peptide-1 receptor (GLP-1R), a family B G-protein coupled receptor (GPCR), regulates the insulin secretion following stimulation by ligands. The transmembrane domain (TM) mediates GLP-1R homodimerization, which modulates its ligand binding and signaling. We investigated the possible involvement of the N-terminal extracellular domain (NTD) in dimerization/oligomerization and dimer-associated ligand binding by NanoLuc Binary Technology (NanoBiT). With improved NanoBiT detection using a decreasing substrate concentration, the negative cooperativity of ligand binding to the NTD was confirmed by accelerated dissociation and Scatchard analysis. The dimerization/oligomerization of the isolated NTD was observed by NanoBiT and validated by analytical ultracentrifugation, deriving the comparable dimerization affinity (~105 M-1 ). The NTD was also involved in the dimerization/oligomerization of the full-length GLP-1R with mutated TM4 at the cellular level. In an analysis of the parameters of the NTD binding, the Kd for the probe GLP-1 (7-36, A8G) was similar (6-8 μM) in both the 1:1 binding model and the receptor dimerization model. Compared with GLP-1 and dulaglutide, exenatide showed two-site binding with Ki values of 1.4 pM and 8.7 nM. Our study indicates the involvement of NTD in the GLP-1R dimerization/oligomerization and suggests that further investigations on the role in other family B GPCRs are needed.
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Affiliation(s)
- Xiaohan Song
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Yi Yu
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Cangjie Shen
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Yubo Wang
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
| | - Nan Wang
- Beijing Key Laboratory of New Drug Mechanisms and Pharmacological Evaluation Study, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, P.R. China
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8
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Wang JH, Nie WH, Shao XX, Li HZ, Hu MJ, Liu YL, Xu ZG, Guo ZY. Exploring electrostatic interactions of relaxin family peptide receptor 3 and 4 with ligands using a NanoBiT-based binding assay. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:776-786. [DOI: 10.1016/j.bbamem.2019.01.010] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/16/2019] [Accepted: 01/21/2019] [Indexed: 12/15/2022]
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9
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Dale NC, Johnstone EKM, White CW, Pfleger KDG. NanoBRET: The Bright Future of Proximity-Based Assays. Front Bioeng Biotechnol 2019; 7:56. [PMID: 30972335 PMCID: PMC6443706 DOI: 10.3389/fbioe.2019.00056] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/04/2019] [Indexed: 12/17/2022] Open
Abstract
Bioluminescence resonance energy transfer (BRET) is a biophysical technique used to monitor proximity within live cells. BRET exploits the naturally occurring phenomenon of dipole-dipole energy transfer from a donor enzyme (luciferase) to an acceptor fluorophore following enzyme-mediated oxidation of a substrate. This results in production of a quantifiable signal that denotes proximity between proteins and/or molecules tagged with complementary luciferase and fluorophore partners. BRET assays have been used to observe an array of biological functions including ligand binding, intracellular signaling, receptor-receptor proximity, and receptor trafficking, however, BRET assays can theoretically be used to monitor the proximity of any protein or molecule for which appropriate fusion constructs and/or fluorophore conjugates can be produced. Over the years, new luciferases and approaches have been developed that have increased the potential applications for BRET assays. In particular, the development of the small, bright and stable Nanoluciferase (NanoLuc; Nluc) and its use in NanoBRET has vastly broadened the potential applications of BRET assays. These advances have exciting potential to produce new experimental methods to monitor protein-protein interactions (PPIs), protein-ligand interactions, and/or molecular proximity. In addition to NanoBRET, Nluc has also been exploited to produce NanoBiT technology, which further broadens the scope of BRET to monitor biological function when NanoBiT is combined with an acceptor. BRET has proved to be a powerful tool for monitoring proximity and interaction, and these recent advances further strengthen its utility for a range of applications.
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Affiliation(s)
- Natasha C Dale
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Elizabeth K M Johnstone
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Carl W White
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia
| | - Kevin D G Pfleger
- Molecular Endocrinology and Pharmacology, Harry Perkins Institute of Medical Research, QEII Medical Centre, Nedlands, WA, Australia.,Centre for Medical Research, The University of Western Australia, Crawley, WA, Australia.,Australian Research Council Centre for Personalised Therapeutics TechnologiesAustralia.,Dimerix Limited, Nedlands, WA, Australia
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Kobayashi H, Picard LP, Schönegge AM, Bouvier M. Bioluminescence resonance energy transfer-based imaging of protein-protein interactions in living cells. Nat Protoc 2019; 14:1084-1107. [PMID: 30911173 DOI: 10.1038/s41596-019-0129-7] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 01/08/2019] [Indexed: 11/09/2022]
Abstract
Bioluminescence resonance energy transfer (BRET) is a transfer of energy between a luminescence donor and a fluorescence acceptor. Because BRET occurs when the distance between the donor and acceptor is <10 nm, and its efficiency is inversely proportional to the sixth power of distance, it has gained popularity as a proximity-based assay to monitor protein-protein interactions and conformational rearrangements in live cells. In such assays, one protein of interest is fused to a bioluminescent energy donor (luciferases from Renilla reniformis or Oplophorus gracilirostris), and the other protein is fused to a fluorescent energy acceptor (such as GFP or YFP). Because the BRET donor does not require an external light source, it does not lead to phototoxicity or autofluorescence. It therefore represents an interesting alternative to fluorescence-based imaging such as FRET. However, the low signal output of BRET energy donors has limited the spatiotemporal resolution of BRET imaging. Here, we describe how recent improvements in detection devices and BRET probes can be used to markedly improve the resolution of BRET imaging, thus widening the field of BRET imaging applications. The protocol described herein involves three main stages. First, cell preparation and transfection require 3 d, including cell culture time. Second, image acquisition takes 10-120 min per sample, after an initial 60 min for microscope setup. Finally, image analysis typically takes 1-2 h. The choices of energy donor, acceptor, luminescent substrates, cameras and microscope setup, as well as acquisition modes to be used for different applications, are also discussed.
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Affiliation(s)
- Hiroyuki Kobayashi
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Louis-Philippe Picard
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Anne-Marie Schönegge
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada
| | - Michel Bouvier
- Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, Montreal, QC, Canada.
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11
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Wang J, Li H, Shao X, Nie W, Liu Y, Xu Z, Guo Z. Identifying the binding mechanism of
LEAP
2 to receptor
GHSR
1a. FEBS J 2019; 286:1332-1345. [PMID: 30666806 DOI: 10.1111/febs.14763] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 11/20/2018] [Accepted: 01/18/2019] [Indexed: 12/26/2022]
Affiliation(s)
- Jia‐Hui Wang
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Hao‐Zheng Li
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Xiao‐Xia Shao
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Wei‐Han Nie
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Ya‐Li Liu
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Zeng‐Guang Xu
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
| | - Zhan‐Yun Guo
- Research Center for Translational Medicine at East Hospital School of Life Sciences and Technology Tongji University Shanghai China
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12
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Wang JH, Shao XX, Hu MJ, Liu YL, Xu ZG, Guo ZY. Functionality of an absolutely conserved glycine residue in the chimeric relaxin family peptide R3/I5. Amino Acids 2019; 51:619-626. [PMID: 30604098 DOI: 10.1007/s00726-018-02694-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Accepted: 12/22/2018] [Indexed: 10/27/2022]
Abstract
The insulin superfamily is a group of homologous proteins that are further divided into the insulin family and relaxin family according to their distinct receptors. All insulin superfamily members contain three absolutely conserved disulfide linkages and a nonchiral Gly residue immediately following the first B-chain cysteine. The functionality of this conserved Gly residue in the insulin family has been studied by replacing it with natural L-amino acids or the corresponding unnatural D-amino acids. However, such analysis has not been conducted on relaxin family members. In the present study, we conducted chiral mutagenesis on the conserved B11Gly of the chimeric relaxin family peptide R3/I5, which is an efficient agonist for receptor RXFP3 and RXFP4. Similar to the effects on insulin family foldability, L-Ala or L-Ser substitution completely abolished the in vitro refolding of a recombinant R3/I5 precursor; whereas, D-Ala or D-Ser substitution had no detrimental effect on refolding of a semi-synthetic R3/I5 precursor, suggesting that the conserved Gly residue controls the foldability of relaxin family members. In contrast to the effect on insulin family activity, D-Ala or D-Ser replacement had no detrimental effect on the binding and activation potencies of the mature R3/I5 towards both RXFP3 and RXFP4, suggesting that the conserved Gly residue is irrelevant to the relaxin family's activity. The present study revealed functionality of the conserved B-chain Gly residue for a relaxin family peptide for the first time, providing an overview of its contribution to foldability and activity of the insulin superfamily.
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Affiliation(s)
- Jia-Hui Wang
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Xiao-Xia Shao
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Meng-Jun Hu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Ya-Li Liu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zeng-Guang Xu
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China
| | - Zhan-Yun Guo
- Research Center for Translational Medicine at East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai, China.
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