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Liang Q, Chi G, Cirqueira L, Zhi L, Marasco A, Pilati N, Gunthorpe MJ, Alvaro G, Large CH, Sauer DB, Treptow W, Covarrubias M. The binding and mechanism of a positive allosteric modulator of Kv3 channels. Nat Commun 2024; 15:2533. [PMID: 38514618 PMCID: PMC10957983 DOI: 10.1038/s41467-024-46813-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Accepted: 03/11/2024] [Indexed: 03/23/2024] Open
Abstract
Small-molecule modulators of diverse voltage-gated K+ (Kv) channels may help treat a wide range of neurological disorders. However, developing effective modulators requires understanding of their mechanism of action. We apply an orthogonal approach to elucidate the mechanism of action of an imidazolidinedione derivative (AUT5), a highly selective positive allosteric modulator of Kv3.1 and Kv3.2 channels. AUT5 modulation involves positive cooperativity and preferential stabilization of the open state. The cryo-EM structure of the Kv3.1/AUT5 complex at a resolution of 2.5 Å reveals four equivalent AUT5 binding sites at the extracellular inter-subunit interface between the voltage-sensing and pore domains of the channel's tetrameric assembly. Furthermore, we show that the unique extracellular turret regions of Kv3.1 and Kv3.2 essentially govern the selective positive modulation by AUT5. High-resolution apo and bound structures of Kv3.1 demonstrate how AUT5 binding promotes turret rearrangements and interactions with the voltage-sensing domain to favor the open conformation.
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Affiliation(s)
- Qiansheng Liang
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Leonardo Cirqueira
- Laboratorio de Biologia Teorica e Computacional, University of Brasilia, Brasilia, Brazil
| | - Lianteng Zhi
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA
| | - Agostino Marasco
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Nadia Pilati
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Martin J Gunthorpe
- Autifony Therapeutics, Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK
| | - Giuseppe Alvaro
- Autifony Srl, Istituto di Ricerca Pediatrica Citta' della Speranza, Via Corso Stati Uniti, 4f, 35127, Padua, Italy
| | - Charles H Large
- Autifony Therapeutics, Ltd, Stevenage Bioscience Catalyst, Gunnels Wood Road, Stevenage, SG1 2FX, UK
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Werner Treptow
- Laboratorio de Biologia Teorica e Computacional, University of Brasilia, Brasilia, Brazil
| | - Manuel Covarrubias
- Department of Neuroscience,, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA.
- Jack and Vicki Farber Institute for Neuroscience and the Jefferson Synaptic Biology Center, Sidney Kimmel Medical College of Thomas Jefferson University, Philadelphia, PA, 19107, USA.
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2
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Raturi S, Li H, Chang YN, Scacioc A, Bohstedt T, Fernandez-Cid A, Evans A, Abrusci P, Balakrishnan A, Pascoa TC, He D, Chi G, Kaur Singh N, Ye M, Li A, Shrestha L, Wang D, Williams EP, Burgess-Brown NA, Dürr KL, Puetter V, Ingles-Prieto A, Sauer DB. High-Throughput Expression and Purification of Human Solute Carriers for Structural and Biochemical Studies. J Vis Exp 2023. [PMID: 37843272 DOI: 10.3791/65878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2023] Open
Abstract
Solute carriers (SLCs) are membrane transporters that import and export a range of endogenous and exogenous substrates, including ions, nutrients, metabolites, neurotransmitters, and pharmaceuticals. Despite having emerged as attractive therapeutic targets and markers of disease, this group of proteins is still relatively underdrugged by current pharmaceuticals. Drug discovery projects for these transporters are impeded by limited structural, functional, and physiological knowledge, ultimately due to the difficulties in the expression and purification of this class of membrane-embedded proteins. Here, we demonstrate methods to obtain high-purity, milligram quantities of human SLC transporter proteins using codon-optimized gene sequences. In conjunction with a systematic exploration of construct design and high-throughput expression, these protocols ensure the preservation of the structural integrity and biochemical activity of the target proteins. We also highlight critical steps in the eukaryotic cell expression, affinity purification, and size-exclusion chromatography of these proteins. Ultimately, this workflow yields pure, functionally active, and stable protein preparations suitable for high-resolution structure determination, transport studies, small-molecule engagement assays, and high-throughput in vitro screening.
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Affiliation(s)
- Sagar Raturi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Huanyu Li
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | | | - Andreea Scacioc
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Tina Bohstedt
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | | | - Adam Evans
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Patrizia Abrusci
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Abilasha Balakrishnan
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Tomas C Pascoa
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Didi He
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Nanki Kaur Singh
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Mingda Ye
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Anna Li
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Leela Shrestha
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Dong Wang
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | - Eleanor P Williams
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford
| | | | - Katharina L Dürr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford;
| | | | - Alvaro Ingles-Prieto
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences;
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford;
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3
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Chi G, Dietz L, Tang H, Snee M, Scacioc A, Wang D, Mckinley G, Mukhopadhyay SM, Pike AC, Chalk R, Burgess-Brown NA, Timmermans JP, van Putte W, Robinson CV, Dürr KL. Structural characterization of human urea transporters UT-A and UT-B and their inhibition. Sci Adv 2023; 9:eadg8229. [PMID: 37774028 PMCID: PMC10541013 DOI: 10.1126/sciadv.adg8229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 08/30/2023] [Indexed: 10/01/2023]
Abstract
In this study, we present the structures of human urea transporters UT-A and UT-B to characterize them at molecular level and to detail the mechanism of UT-B inhibition by its selective inhibitor, UTBinh-14. High-resolution structures of both transporters establish the structural basis for the inhibitor's selectivity to UT-B, and the identification of multiple binding sites for the inhibitor will aid with the development of drug lead molecules targeting both transporters. Our study also discovers phospholipids associating with the urea transporters by combining structural observations, native MS, and lipidomics analysis. These insights improve our understanding of urea transporter function at a molecular level and provide a blueprint for a structure-guided design of therapeutics targeting these transporters.
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Affiliation(s)
- Gamma Chi
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Larissa Dietz
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Haiping Tang
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Matthew Snee
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
| | - Andreea Scacioc
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Dong Wang
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Gavin Mckinley
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Shubhashish M. M. Mukhopadhyay
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Ashley C. W. Pike
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Rod Chalk
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Nicola A. Burgess-Brown
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
| | - Jean-Pierre Timmermans
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
| | - Wouter van Putte
- Laboratory of Cell Biology and Histology (CBH) at Antwerp Centre for Advanced Microscopy (ACAM), Department of Veterinary Sciences, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp, Belgium
- PUXANO, Ottergemsesteenweg Zuid 713, 9000 Gent, Belgium
| | - Carol V. Robinson
- Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK
- Kavli Institute for Nanoscience Discovery, University of Oxford, Oxford OX1 3QU, UK
| | - Katharina L. Dürr
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford OX3 7DQ, UK
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Nuffield Department of Medicine Research Building, Oxford OX3 7FZ, UK
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4
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Chi G, Liang Q, Sridhar A, Cowgill JB, Sader K, Radjainia M, Qian P, Castro-Hartmann P, Venkaya S, Singh NK, McKinley G, Fernandez-Cid A, Mukhopadhyay SMM, Burgess-Brown NA, Delemotte L, Covarrubias M, Dürr KL. Cryo-EM structure of the human Kv3.1 channel reveals gating control by the cytoplasmic T1 domain. Nat Commun 2022; 13:4087. [PMID: 35840580 PMCID: PMC9287412 DOI: 10.1038/s41467-022-29594-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 03/24/2022] [Indexed: 11/26/2022] Open
Abstract
Kv3 channels have distinctive gating kinetics tailored for rapid repolarization in fast-spiking neurons. Malfunction of this process due to genetic variants in the KCNC1 gene causes severe epileptic disorders, yet the structural determinants for the unusual gating properties remain elusive. Here, we present cryo-electron microscopy structures of the human Kv3.1a channel, revealing a unique arrangement of the cytoplasmic tetramerization domain T1 which facilitates interactions with C-terminal axonal targeting motif and key components of the gating machinery. Additional interactions between S1/S2 linker and turret domain strengthen the interface between voltage sensor and pore domain. Supported by molecular dynamics simulations, electrophysiological and mutational analyses, we identify several residues in the S4/S5 linker which influence the gating kinetics and an electrostatic interaction between acidic residues in α6 of T1 and R449 in the pore-flanking S6T helices. These findings provide insights into gating control and disease mechanisms and may guide strategies for the design of pharmaceutical drugs targeting Kv3 channels.
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Affiliation(s)
- Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Qiansheng Liang
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Akshay Sridhar
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - John B Cowgill
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Kasim Sader
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Mazdak Radjainia
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pu Qian
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Pablo Castro-Hartmann
- Materials and Structural Analysis, Thermo Fisher Scientific, Achtseweg Noord 5, 5651 GG, Eindhoven, Netherlands
| | - Shayla Venkaya
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nanki Kaur Singh
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Gavin McKinley
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
| | - Alejandra Fernandez-Cid
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Shubhashish M M Mukhopadhyay
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exscientia Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK
| | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK
- Exact Sciences Ltd., The Sherard Building, Edmund Halley Road, The Oxford Science Park, Oxford, OX4 4DQ, UK
| | - Lucie Delemotte
- Department of Applied Physics, Science for Life Laboratory, KTH, Solna, Sweden
| | - Manuel Covarrubias
- Department of Neuroscience and Vickie and Jack Farber Institute for Neuroscience, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, 19107, UK
| | - Katharina L Dürr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- Structural Genomics Consortium, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7DQ, UK.
- OMass Therapeutics, Ltd., The Schrödinger Building, Heatley Road, The Oxford Science Park, Oxford, OX4 4GE, UK.
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5
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Kelly JJ, Tranter D, Pardon E, Chi G, Kramer H, Happonen L, Knee KM, Janz JM, Steyaert J, Bulawa C, Paavilainen VO, Huiskonen JT, Yue WW. Snapshots of actin and tubulin folding inside the TRiC chaperonin. Nat Struct Mol Biol 2022; 29:420-429. [PMID: 35449234 PMCID: PMC9113939 DOI: 10.1038/s41594-022-00755-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 03/01/2022] [Indexed: 01/16/2023]
Abstract
The integrity of a cell's proteome depends on correct folding of polypeptides by chaperonins. The chaperonin TCP-1 ring complex (TRiC) acts as obligate folder for >10% of cytosolic proteins, including he cytoskeletal proteins actin and tubulin. Although its architecture and how it recognizes folding substrates are emerging from structural studies, the subsequent fate of substrates inside the TRiC chamber is not defined. We trapped endogenous human TRiC with substrates (actin, tubulin) and cochaperone (PhLP2A) at different folding stages, for structure determination by cryo-EM. The already-folded regions of client proteins are anchored at the chamber wall, positioning unstructured regions toward the central space to achieve their native fold. Substrates engage with different sections of the chamber during the folding cycle, coupled to TRiC open-and-close transitions. Further, the cochaperone PhLP2A modulates folding, acting as a molecular strut between substrate and TRiC chamber. Our structural snapshots piece together an emerging model of client protein folding within TRiC.
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Affiliation(s)
- John J Kelly
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Dale Tranter
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland
| | - Els Pardon
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK
| | - Holger Kramer
- Biological Mass Spectrometry and Proteomics Facility, MRC London Institute of Medical Sciences, Imperial College London, Hammersmith Hospital Campus, London, UK
| | - Lotta Happonen
- Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Kelly M Knee
- Pfizer Rare Disease Research Unit, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA
| | - Jay M Janz
- Pfizer Rare Disease Research Unit, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA
| | - Jan Steyaert
- Structural Biology Brussels, Vrije Universiteit Brussel (VUB), Brussels, Belgium
- VIB-VUB Center for Structural Biology, VIB, Brussels, Belgium
| | - Christine Bulawa
- Pfizer Rare Disease Research Unit, Worldwide Research and Development, Pfizer Inc., Cambridge, MA, USA
| | - Ville O Paavilainen
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland
| | - Juha T Huiskonen
- Institute of Biotechnology, Helsinki Institute of Life Science HiLIFE, University of Helsinki, Helsinki, Finland.
- Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
- Division of Structural Biology, Wellcome Centre for Human Genetics, Roosevelt Drive, University of Oxford, Oxford, UK.
| | - Wyatt W Yue
- Centre for Medicines Discovery, Nuffield Department of Clinical Medicine, University of Oxford, Oxford, UK.
- Biosciences Institute, Medical School, Newcastle University, Newcastle upon Tyne, UK.
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6
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Chi G, Ebenhoch R, Man H, Tang H, Tremblay LE, Reggiano G, Qiu X, Bohstedt T, Liko I, Almeida FG, Garneau AP, Wang D, McKinley G, Moreau CP, Bountra KD, Abrusci P, Mukhopadhyay SMM, Fernandez‐Cid A, Slimani S, Lavoie JL, Burgess‐Brown NA, Tehan B, DiMaio F, Jazayeri A, Isenring P, Robinson CV, Dürr KL. Phospho-regulation, nucleotide binding and ion access control in potassium-chloride cotransporters. EMBO J 2021; 40:e107294. [PMID: 34031912 PMCID: PMC8280820 DOI: 10.15252/embj.2020107294] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 03/29/2021] [Accepted: 04/11/2021] [Indexed: 11/26/2022] Open
Abstract
Potassium-coupled chloride transporters (KCCs) play crucial roles in regulating cell volume and intracellular chloride concentration. They are characteristically inhibited under isotonic conditions via phospho-regulatory sites located within the cytoplasmic termini. Decreased inhibitory phosphorylation in response to hypotonic cell swelling stimulates transport activity, and dysfunction of this regulatory process has been associated with various human diseases. Here, we present cryo-EM structures of human KCC3b and KCC1, revealing structural determinants for phospho-regulation in both N- and C-termini. We show that phospho-mimetic KCC3b is arrested in an inward-facing state in which intracellular ion access is blocked by extensive contacts with the N-terminus. In another mutant with increased isotonic transport activity, KCC1Δ19, this interdomain interaction is absent, likely due to a unique phospho-regulatory site in the KCC1 N-terminus. Furthermore, we map additional phosphorylation sites as well as a previously unknown ATP/ADP-binding pocket in the large C-terminal domain and show enhanced thermal stabilization of other CCCs by adenine nucleotides. These findings provide fundamentally new insights into the complex regulation of KCCs and may unlock innovative strategies for drug development.
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Affiliation(s)
- Gamma Chi
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Rebecca Ebenhoch
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
MedChem, Boehringer Ingelheim Pharma GmbH & Co. KGBiberachGermany
| | - Henry Man
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Haiping Tang
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Laurence E Tremblay
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | | | - Xingyu Qiu
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Tina Bohstedt
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | | | - Alexandre P Garneau
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Dong Wang
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Gavin McKinley
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Christophe P Moreau
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Present address:
Celonic AGBaselGermany
| | | | - Patrizia Abrusci
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- Present address:
Exscientia LtdOxfordUK
| | - Shubhashish M M Mukhopadhyay
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Alejandra Fernandez‐Cid
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | - Samira Slimani
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Julie L Lavoie
- Cardiometabolic Axis, School of Kinesiology and Physical Activity SciencesUniversity of MontréalMontréalQCCanada
| | - Nicola A Burgess‐Brown
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
| | | | - Frank DiMaio
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | | | - Paul Isenring
- Department of MedicineNephrology Research GroupFaculty of MedicineLaval UniversityQuebec CityQCCanada
| | - Carol V Robinson
- Physical and Theoretical Chemistry LaboratoryUniversity of OxfordOxfordUK
| | - Katharina L Dürr
- Nuffield Department of MedicineCentre of Medicines DiscoveryUniversity of OxfordOxfordUK
- Structural Genomics ConsortiumNuffield Department of MedicineUniversity of OxfordOxfordUK
- OMass Therapeutics, Ltd.OxfordUK
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7
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Mahajan P, Ellis K, Mukhopadhyay S, Fernandez-Cid A, Chi G, Man H, Dürr KL, Burgess-Brown NA. Expression Screening of Human Integral Membrane Proteins Using BacMam. Methods Mol Biol 2021; 2199:95-115. [PMID: 33125646 DOI: 10.1007/978-1-0716-0892-0_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This chapter describes the step-by-step methods employed by the Structural Genomics Consortium (SGC) for screening and producing proteins in the BacMam system. This eukaryotic expression system was selected and a screening process established in 2016 to enable production of highly challenging human integral membrane proteins (IMPs), which are a significant component of our target list. Here, we discuss our recently developed platform for identifying expression and monodispersity of IMPs from 3 mL of HEK293 cells.
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Affiliation(s)
| | | | | | | | - Gamma Chi
- Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Henry Man
- Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Katharina L Dürr
- Structural Genomics Consortium, University of Oxford, Oxford, UK
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Kalayci A, Gibson CM, Chi G, Yee M, Korjian S, Datta S, Nafee T, Gurin M, Haroian N, Hull RD, Hernandez AF, Cohen AT, Harrington RA, Goldhaber SZ. P251Asymptomatic deep vein thrombosis in acutely ill medical patients: insights from the APEX trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy564.p251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- A Kalayci
- Harvard Medical School, Cardiology, Boston, United States of America
| | - C M Gibson
- Harvard Medical School, Cardiology, Boston, United States of America
| | - G Chi
- Harvard Medical School, Cardiology, Boston, United States of America
| | - M Yee
- Harvard Medical School, Cardiology, Boston, United States of America
| | - S Korjian
- Harvard Medical School, Cardiology, Boston, United States of America
| | - S Datta
- Harvard Medical School, Cardiology, Boston, United States of America
| | - T Nafee
- Harvard Medical School, Cardiology, Boston, United States of America
| | - M Gurin
- Harvard Medical School, Cardiology, Boston, United States of America
| | - N Haroian
- Harvard Medical School, Cardiology, Boston, United States of America
| | - R D Hull
- University of Calgary, Cardiology, Calgary, Canada
| | - A F Hernandez
- Duke University Medical Center, Cardiology, Durham, United States of America
| | - A T Cohen
- St Thomas' Hospital, Haematology, London, United Kingdom
| | - R A Harrington
- Stanford University Medical Center, Cardiology, Stanford, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Cardiology, Boston, United States of America
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9
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Nafee T, Gibson CM, Yee MK, Travis R, Kerneis M, Chi G, Alkhalfan F, Daaboul Y, Korjian S, Bandman O, Hernandez AF, Hull RD, Cohen AT, Harrington RA, Goldhaber SZ. P6072Characterization of major and clinically relevant non-major bleeding in the APEX trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy566.p6072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- T Nafee
- Harvard Medical School, Division of Cardiovascular Medicine, Boston, United States of America
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M K Yee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R Travis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Kerneis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - G Chi
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - F Alkhalfan
- Harvard Medical School, Division of Cardiovascular Medicine, Boston, United States of America
| | - Y Daaboul
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - S Korjian
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - O Bandman
- Portola Pharmaceuticals Inc., South San Francisco, United States of America
| | - A F Hernandez
- Duke Clinical Research Institute, Durham, United States of America
| | - R D Hull
- University of Calgary, Calgary, Canada
| | - A T Cohen
- Guy's Hospital, London, United Kingdom
| | - R A Harrington
- Stanford University Medical Center, Department of Medicine, Stanford, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Boston, United States of America
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Chi G, Gibson CM, Hernandez AF, Hull RD, Kalayci A, Kerneis M, Alkhalfan F, Nafee T, Cohen AT, Harrington RA, Goldhaber SZ. P1623Association of low hemoglobin with venous thromboembolism in acutely ill hospitalized medical patients: findings from the APEX trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.p1623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- G Chi
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - A F Hernandez
- Duke Clinical Research Institute, Durham, United States of America
| | - R D Hull
- University of Calgary, Calgary, Canada
| | - A Kalayci
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - M Kerneis
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - F Alkhalfan
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - T Nafee
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - A T Cohen
- Guy's Hospital, London, United Kingdom
| | - R A Harrington
- Stanford University Medical Center, Stanford, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Boston, United States of America
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11
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Yee MK, Kerneis M, Nafee T, Travis R, Chi G, Mehran R, Wildegoose P, Bode C, Halperin J, Verheugt FW, Lip GYH, Cohen M, Peterson ED, Fox KAA, Gibson CM. 1460Effect of the INR stability characteristics on bleeding events among atrial fibrillation patients undergoing percutaneous coronary intervention: insights from the PIONEER AF-PCI trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.1460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M K Yee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Kerneis
- Harvard Medical School, Division of Cardiovascular Medicine, Boston, United States of America
| | - T Nafee
- Harvard Medical School, Division of Cardiovascular Medicine, Boston, United States of America
| | - R Travis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - G Chi
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R Mehran
- Mount Sinai Medical Center, Cardiovascular Institute, New York, United States of America
| | - P Wildegoose
- Janssen Pharmaceuticals, Titusville, United States of America
| | - C Bode
- University of Freiburg, Heart Center, Department of Cardiology and Angiology, Freiburg, Germany
| | - J Halperin
- Mount Sinai Medical Center, Cardiovascular Institute, New York, United States of America
| | - F W Verheugt
- Hospital Onze Lieve Vrouwe Gasthuis, Amsterdam, Netherlands
| | - G Y H Lip
- Birmingham City Hospital, Birmingham, United Kingdom
| | - M Cohen
- Newark Beth Israel Medical Center, Newark, United States of America
| | - E D Peterson
- Duke Clinical Research Institute, Durham, United States of America
| | - K A A Fox
- Royal Infirmary of Edinburgh, Edinburgh, United Kingdom
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
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Yee MK, Gibson CM, Nafee T, Kerneis M, Travis R, Alkhalfan F, Chi G, Datta S, Jafarizade M, Ghaffarpasand E, Hull RD, Hernandez AF, Cohen AT, Harrington RA, Goldhaber SZ. 109Betrixaban compared to enoxaparin among obese acute medically ill subjects: an APEX trial subgroup analysis. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy564.109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- M K Yee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - T Nafee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Kerneis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R Travis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - F Alkhalfan
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - G Chi
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - S Datta
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Jafarizade
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - E Ghaffarpasand
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R D Hull
- University of Calgary, Calgary, Canada
| | - A F Hernandez
- Duke Clinical Research Institute, Durham, United States of America
| | - A T Cohen
- Guy's Hospital, London, United Kingdom
| | - R A Harrington
- Stanford University, Department of Medicine, Palo Alto, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Boston, United States of America
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13
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Nafee T, Gibson CM, Travis R, Kerneis M, Yee MK, Alkhalfan F, Chi G, Kalayci A, Mir M, Alihashemi M, Hull RD, Hernandez AF, Cohen AT, Harrington RA, Goldhaber SZ. 2160Performance of a machine learning model vs. IMPROVE score for VTE prediction in acute medically ill patients: insights from the APEX trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy565.2160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- T Nafee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R Travis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Kerneis
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M K Yee
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - F Alkhalfan
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - G Chi
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - A Kalayci
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Mir
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - M Alihashemi
- Beth Israel Deaconess Medical Center, Division of Cardiovascular Medicine, Boston, United States of America
| | - R D Hull
- University of Calgary, Calgary, Canada
| | - A F Hernandez
- Duke Clinical Research Institute, Durham, United States of America
| | - A T Cohen
- Guy's Hospital, London, United Kingdom
| | - R A Harrington
- Stanford University, Department of Medicine, Stanford, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Boston, United States of America
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Chi G, Gibson CM, Hernandez AF, Hull RD, Cohen AT, Harrington RA, Alkhalfan F, Kalayci A, Kerneis M, Nafee T, Goldhaber SZ. 4321Betrixaban versus enoxaparin for venous thromboembolism prophylaxis in critically ill patients: findings from the APEX trial. Eur Heart J 2018. [DOI: 10.1093/eurheartj/ehy563.4321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- G Chi
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - C M Gibson
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - A F Hernandez
- Duke Clinical Research Institute, Durham, United States of America
| | - R D Hull
- University of Calgary, Calgary, Canada
| | - A T Cohen
- Guy's Hospital, London, United Kingdom
| | - R A Harrington
- Stanford University Medical Center, Stanford, United States of America
| | - F Alkhalfan
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - A Kalayci
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - M Kerneis
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - T Nafee
- Beth Israel Deaconess Medical Center, Cardiology, Boston, United States of America
| | - S Z Goldhaber
- Brigham and Women's Hospital, Boston, United States of America
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Chi G, Yee M, Amin A, Goldhaber S, Hernandez A, Hull R. Extended-Duration Betrixaban Reduces the Risk of Rehospitalization Associated With Venous Thromboembolism Among Acutely Ill Hospitalized Medical Patients: Findings From the Apex Trial (Acute Medically Ill Venous Thromboembolism Prevention With Extended Duration Betrixaban Trial). J Vasc Surg Venous Lymphat Disord 2018. [DOI: 10.1016/j.jvsv.2018.05.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Chi G, Goldhaber SZ, Kittelson JM, Turpie AGG, Hernandez AF, Hull RD, Gold A, Curnutte JT, Cohen AT, Harrington RA, Gibson CM. Effect of extended-duration thromboprophylaxis on venous thromboembolism and major bleeding among acutely ill hospitalized medical patients: a bivariate analysis. J Thromb Haemost 2017; 15:1913-1922. [PMID: 28762617 DOI: 10.1111/jth.13783] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Indexed: 11/30/2022]
Abstract
Essentials Anticoagulants prevent venous thromboembolism but may be associated with greater bleeding risks. Bivariate analysis assumes a non-linear relationship between efficacy and safety outcomes. Extended full-dose betrixaban is favorable over standard enoxaparin in bivariate endpoint. Clinicians must weigh efficacy and safety outcomes in decision-making on thromboprophylaxis. SUMMARY Background Among acutely ill hospitalized medical patients, extended-duration thromboprophylaxis reduces the risk of venous thromboembolism (VTE), but some pharmacologic strategies have been associated with greater risks of major bleeding, thereby offsetting the net clinical benefit (NCB). Methods To assess the risk-benefit profile of anticoagulation regimens, a previously described bivariate method that does not assume a linear risk-benefit tradeoff and can accommodate different margins for efficacy and safety was performed to simultaneously assess efficacy (symptomatic VTE) and safety (major bleeding) on the basis of data from four randomized controlled trials of extended-duration (30-46 days) versus standard-duration (6-14 days) thromboprophylaxis among 28 227 patients (EXCLAIM, ADOPT, MAGELLAN and APEX trials). Results Extended thromboprophylaxis with full-dose betrixaban (80 mg once daily) was superior in efficacy and non-inferior in safety to standard-duration enoxaparin, and showed a significantly favorable NCB, with a risk difference of - 0.51% (- 0.89% to - 0.10%) in the bivariate outcome. Extended enoxaparin was superior in efficacy and inferior in safety (bivariate outcome: 0.03% [- 0.37% to 0.43%]), whereas apixaban and rivaroxaban were non-inferior in efficacy and inferior in safety (- 0.20% [- 0.49% to 0.17%] and 0.23% [- 0.16% to 0.69%], respectively). Reduced-dose betrixaban did not show a significant difference in either efficacy or safety (0.41% [- 0.85% to 1.94%]). Conclusions In a bivariate analysis that assumes non-linear risk-benefit tradeoffs, extended prophylaxis with full-dose betrixaban was superior to standard-duration enoxaparin, whereas other regimens failed to simultaneously achieve both superiority and non-inferiority with respect to symptomatic VTE and major bleeding in the management of acutely ill hospitalized medical patients.
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Affiliation(s)
- G Chi
- Cardiovascular Division, Departments of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - S Z Goldhaber
- Cardiovascular Division, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - J M Kittelson
- Department of Biostatistics and Informatics, Colorado School of Public Health, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - A G G Turpie
- Department of Medicine, Hamilton Health Sciences, General Division, Hamilton, Ontario, Canada
| | - A F Hernandez
- Duke University and Duke Clinical Research Institute, Durham, NC, USA
| | - R D Hull
- Division of Cardiology, R. A. H. Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - A Gold
- Portola Pharmaceuticals Inc., South San Francisco, CA, USA
| | - J T Curnutte
- Portola Pharmaceuticals Inc., South San Francisco, CA, USA
| | - A T Cohen
- Department of Haematological Medicine, Guy's and St Thomas' Hospitals, King's College, London, UK
| | - R A Harrington
- Division of Cardiovascular Medicine, Department of Medicine, Stanford University, Stanford, CA, USA
| | - C M Gibson
- Cardiovascular Division, Departments of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
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Chi G, Nafee T, Korjian S, Daaboul Y, Harrington R, Goldhaber S, Hull R, Gold A, Cohen A, Gibson C. P5599Effect of extended-duration thromboprophylaxis on venous thromboembolism and major bleeding among acutely ill hospitalized medical patients: a bivariate analysis. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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18
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Gibson C, Arbetter D, Jain P, Halaby R, Chi G, Nafee T, Korjian S, Daaboul Y, Harrington R, Goldhaber S, Hull R, Gold A, Cohen A. P1551D-dimer concentration is associated with increased risk for VTE and greater absolute benefit of extended prophylaxis with betrixaban in acutely Ill medical patients: insights from the APEX trial. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.p1551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Gibson C, Arbetter D, Jain P, Halaby R, Chi G, Nafee T, Korjian S, Daaboul Y, Goldhaber S, Hull R, Gold A, Hernandez A, Cohen A, Harrington R. P1732Extended duration betrixaban in acutely ill medical patients is associated with reduction in fatal or irreversible ischemic or bleeding events compared with standard dose enoxaparin: an APEX substudy. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx502.p1732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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20
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Chi G, Korjian S, Daaboul Y, Nafee T, Mehran R, Bode C, Halperin J, Verheugt F, Wildgoose P, Eickels M, Lip G, Cohen M, Peterson E, Fox K, Gibson C. P6112Effect of procedure and lesion characteristics on bleeding and ischemic outcomes among atrial fibrillation patients undergoing percutaneous coronary intervention: results from the PIONEER AF-PCI trial. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p6112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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21
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Chi G, Nafee T, Korjian S, Daaboul Y, Harrington R, Goldhaber S, Hull R, Gold A, Cohen A, Gibson C. P4316N-terminal pro-B-type natriuretic peptide (NT-proBNP) is associated with stroke among hospitalized medical patients: an APEX trial substudy. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx504.p4316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Yee M, Chi G, Nafee T, Korjian S, Daaboul Y, Harrington R, Goldhaber S, Hull R, Gold A, Cohen A, Gibson C. P5600History of venous thromboembolism is associated with higher risk for recurrent venous thromboembolism: insights from the APEX trial. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx493.p5600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Yee M, Chi G, Jain P, Mehran R, Bode C, Halperin J, Verheugt F, Wildgoose P, Korjian S, Daaboul Y, Lip G, Cohen M, Peterson E, Fox K, Gibson C. P4565Rivaroxaban treatment strategies reduce not only the first bleeding event, but all (including multiple) bleeding events: A PIONEER Substudy. Eur Heart J 2017. [DOI: 10.1093/eurheartj/ehx504.p4565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Chi G, Rohde PR, Ridone P, Hankamer B, Martinac B, Landsberg MJ. Functional similarities between heterogeneously and homogenously expressed MscL constructs. Eur Biophys J 2015; 44:589-98. [PMID: 26233759 DOI: 10.1007/s00249-015-1062-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 06/29/2015] [Accepted: 07/14/2015] [Indexed: 11/30/2022]
Abstract
The mechanosensitive channel of large conductance MscL is a well-characterized mechanically gated non-selective ion channel, which often serves as a prototype mechanosensitive channel for mechanotransduction studies. However, there are some discrepancies between MscL constructs used in these studies, most notably unintended heterogeneous expression from some MscL expression constructs. In this study we investigate the possible cause of this expression pattern, and compare the original non-homogenously expressing constructs with our new homogeneously expressing one to confirm that there is little functional difference between them. In addition, a new MscL construct has been developed with an improved molar extinction coefficient at 280 nm, enabling more accurate protein quantification.
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Affiliation(s)
- Gamma Chi
- Institute for Molecular Bioscience, The University of Queensland, St Lucia, QLD, 4072, Australia
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25
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Martinac B, Nomura T, Chi G, Petrov E, Rohde PR, Battle AR, Foo A, Constantine M, Rothnagel R, Carne S, Deplazes E, Cornell B, Cranfield CG, Hankamer B, Landsberg MJ. Bacterial mechanosensitive channels: models for studying mechanosensory transduction. Antioxid Redox Signal 2014; 20:952-69. [PMID: 23834368 DOI: 10.1089/ars.2013.5471] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
SIGNIFICANCE Sensations of touch and hearing are manifestations of mechanical contact and air pressure acting on touch receptors and hair cells of the inner ear, respectively. In bacteria, osmotic pressure exerts a significant mechanical force on their cellular membrane. Bacteria have evolved mechanosensitive (MS) channels to cope with excessive turgor pressure resulting from a hypo-osmotic shock. MS channel opening allows the expulsion of osmolytes and water, thereby restoring normal cellular turgor and preventing cell lysis. RECENT ADVANCES As biological force-sensing systems, MS channels have been identified as the best examples of membrane proteins coupling molecular dynamics to cellular mechanics. The bacterial MS channel of large conductance (MscL) and MS channel of small conductance (MscS) have been subjected to extensive biophysical, biochemical, genetic, and structural analyses. These studies have established MscL and MscS as model systems for mechanosensory transduction. CRITICAL ISSUES In recent years, MS ion channels in mammalian cells have moved into focus of mechanotransduction research, accompanied by an increased awareness of the role they may play in the pathophysiology of diseases, including cardiac hypertrophy, muscular dystrophy, or Xerocytosis. FUTURE DIRECTIONS A recent exciting development includes the molecular identification of Piezo proteins, which function as nonselective cation channels in mechanosensory transduction associated with senses of touch and pain. Since research on Piezo channels is very young, applying lessons learned from studies of bacterial MS channels to establishing the mechanism by which the Piezo channels are mechanically activated remains one of the future challenges toward a better understanding of the role that MS channels play in mechanobiology.
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Affiliation(s)
- Boris Martinac
- 1 Molecular Cardiology and Biophysics Division/Mechanosensory Biophysics Laboratory, Victor Chang Cardiac Research Institute , Darlinghurst, Australia
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Chi G, Manos-Turvey A, O’Connor PD, Johnston JM, Evans GL, Baker EN, Payne RJ, Lott JS, Bulloch EMM. Implications of Binding Mode and Active Site Flexibility for Inhibitor Potency against the Salicylate Synthase from Mycobacterium tuberculosis. Biochemistry 2012; 51:4868-79. [DOI: 10.1021/bi3002067] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Gamma Chi
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | | | - Patrick D. O’Connor
- Auckland Cancer Society Research
Centre, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Jodie M. Johnston
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Genevieve L. Evans
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Edward N. Baker
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Richard J. Payne
- School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
| | - J. Shaun Lott
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
| | - Esther M. M. Bulloch
- School of Biological Sciences
and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3 Symonds Street, Private
Bag 92019, Auckland 1142, New Zealand
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Manos-Turvey A, Cergol KM, Salam NK, Bulloch EMM, Chi G, Pang A, Britton WJ, West NP, Baker EN, Lott JS, Payne RJ. Synthesis and evaluation of M. tuberculosis salicylate synthase (MbtI) inhibitors designed to probe plasticity in the active site. Org Biomol Chem 2012; 10:9223-36. [DOI: 10.1039/c2ob26736e] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Dong X, Peek-Asa C, Yang J, Wang S, Chen X, Chi G, Marizen R. The association of road safety knowledge, risk behaviour and road traffic injury among school-aged children in Guangzhou, China. Inj Prev 2010. [DOI: 10.1136/ip.2010.029215.125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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29
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Chi G, Wang S. An epidemiological study on road traffic injury in China. Inj Prev 2010. [DOI: 10.1136/ip.2010.029215.439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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30
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Chi G, Chen H, Wang S. An epidemiological investigation and analysis on its influence factors of campus violence on secondary schools in China. Inj Prev 2010. [DOI: 10.1136/ip.2010.029215.440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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31
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Chi G, Wang S, Liu R. [An epidemiological analysis on the relationship between road injury and traffic environment in China]. Zhonghua Liu Xing Bing Xue Za Zhi 2000; 21:330-2. [PMID: 11860807] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To explore the influence of traffic environment on road injury so as to provide basis for prevention and control. METHODS Principal component regression analysis was used to explain the relationship between road injury and the numbers of vehicle, capacity of road transport and mileage of rigid highway. RESULTS Results showed a positive correlation between level of personal safety (LPS) and the numbers of vehicle, volume of road haulage, volume of passenger transport, mileage of rigid highway (correlation coefficients were 0.8714, 0.9691, 0.9611, 0.9510, P = 0.0005). The numbers of vehicle, volume of road haulage, volume of passenger transport and mileage of rigid highway were increasing when LPS decreased. Principal component regression analysis overcame multi collinearty of independent variables and obtained a regression equation y =-3.7197 + 1.49E-03X(1) + 5.2E-06X(3) + 6.19E-02X(4). CONCLUSION The primary determinants of LPS were numbers of vehicle, volume of road haulage, volume of passenger and mileage of rigid highway. Road injury thus could be reduced through improving the traffic environment, strengthening the traffic administration as well as promoting traffic safety.
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Affiliation(s)
- G Chi
- Medical College of Jinan University, Guangzhou 510632, China
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Hu Y, Wang S, Chi G. [Epidemiologic features and the stepwise regression analysis of fatal motor vehicle accidents in Guangzhou]. Zhonghua Liu Xing Bing Xue Za Zhi 1994; 15:114-6. [PMID: 7923333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This paper describes the epidemiologic features of 1,532 fatal motor vehicle crashes, and analyses of some crash-related factors by means of stepwise regression analysis as well. The crashes between motor vehicle and bicycle accounted for 39.49 percent. The 36.84 percent of drivers responsible for accidents were at the age of 20-24. The analysis of accident victim characteristics indicated that all age groups were at risk. Most victims were the people younger than 25 years old as well as aged 50 and over. About one-third of the victims were peasants. The analysis of stepwise regression suggested that the crashes were positively related to the quantity of automobile and the ratio between male and female.
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Affiliation(s)
- Y Hu
- Department of Epidemiology, Medical College of Jinan University, Guangzhou
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