1
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You R, Jia Z. Pathophysiological role of Na-Cl cotransporter in kidneys, blood pressure, and metabolism. Hum Cell 2024:10.1007/s13577-024-01099-2. [PMID: 38985392 DOI: 10.1007/s13577-024-01099-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 07/02/2024] [Indexed: 07/11/2024]
Abstract
The Na-Cl cotransporter (NCC) is a well-recognized regulator of ion transportation in the kidneys that facilitates Na+ reabsorption in the distal convoluted tubule. It is also the pharmacologic inhibitory target of thiazide diuretics, a class of front-line antihypertensive agents that have been widely used for decades. NCC is a potent regulator of Na+ reabsorption and homeostasis. Hence, its overactivation and suppression lead to hypertension and hypotension, respectively. Genetic mutations that affect NCC function contribute to several diseases such as Gordon and Gitelman syndromes. We summarized the role of NCC in various physiologic processes and pathological conditions, such as maintaining ion and water homeostasis, controlling blood pressure, and influencing renal physiology and injury. In addition, we discussed the recent advancements in understanding cryo-EM structure of NCC, the regulatory mechanisms and binding mode of thiazides with NCC, and novel physiologic implications of NCC in regulating the cross-talk between the immune system and adipose tissue or the kidneys. This review contributes to a comprehensive understanding of the pivotal role of NCC in maintaining ion homeostasis, regulating blood pressure, and facilitating kidney function and NCC's novel role in immune and metabolic regulation.
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Affiliation(s)
- Ran You
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, 72 Guangzhou Road, Nanjing, 210008, China.
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.
| | - Zhanjun Jia
- Nanjing Key Laboratory of Pediatrics, Children's Hospital of Nanjing Medical University, 72 Guangzhou Road, Nanjing, 210008, China.
- Jiangsu Key Laboratory of Pediatrics, Nanjing Medical University, Nanjing, China.
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2
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Kok M, Brodsky JL. The biogenesis of potassium transporters: implications of disease-associated mutations. Crit Rev Biochem Mol Biol 2024:1-45. [PMID: 38946646 DOI: 10.1080/10409238.2024.2369986] [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: 03/29/2024] [Accepted: 06/16/2024] [Indexed: 07/02/2024]
Abstract
The concentration of intracellular and extracellular potassium is tightly regulated due to the action of various ion transporters, channels, and pumps, which reside primarily in the kidney. Yet, potassium transporters and cotransporters play vital roles in all organs and cell types. Perhaps not surprisingly, defects in the biogenesis, function, and/or regulation of these proteins are linked to range of catastrophic human diseases, but to date, few drugs have been approved to treat these maladies. In this review, we discuss the structure, function, and activity of a group of potassium-chloride cotransporters, the KCCs, as well as the related sodium-potassium-chloride cotransporters, the NKCCs. Diseases associated with each of the four KCCs and two NKCCs are also discussed. Particular emphasis is placed on how these complex membrane proteins fold and mature in the endoplasmic reticulum, how non-native forms of the cotransporters are destroyed in the cell, and which cellular factors oversee their maturation and transport to the cell surface. When known, we also outline how the levels and activities of each cotransporter are regulated. Open questions in the field and avenues for future investigations are further outlined.
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Affiliation(s)
- Morgan Kok
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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3
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Rioux AV, Nsimba-Batomene TR, Slimani S, Bergeron NAD, Gravel MAM, Schreiber SV, Fiola MJ, Haydock L, Garneau AP, Isenring P. Navigating the multifaceted intricacies of the Na +-Cl - cotransporter, a highly regulated key effector in the control of hydromineral homeostasis. Physiol Rev 2024; 104:1147-1204. [PMID: 38329422 DOI: 10.1152/physrev.00027.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Revised: 01/01/2024] [Accepted: 02/03/2024] [Indexed: 02/09/2024] Open
Abstract
The Na+-Cl- cotransporter (NCC; SLC12A3) is a highly regulated integral membrane protein that is known to exist as three splice variants in primates. Its primary role in the kidney is to mediate the cosymport of Na+ and Cl- across the apical membrane of the distal convoluted tubule. Through this role and the involvement of other ion transport systems, NCC allows the systemic circulation to reclaim a fraction of the ultrafiltered Na+, K+, Cl-, and Mg+ loads in exchange for Ca2+ and [Formula: see text]. The physiological relevance of the Na+-Cl- cotransport mechanism in humans is illustrated by several abnormalities that result from NCC inactivation through the administration of thiazides or in the setting of hereditary disorders. The purpose of the present review is to discuss the molecular mechanisms and overall roles of Na+-Cl- cotransport as the main topics of interest. On reading the narrative proposed, one will realize that the knowledge gained in regard to these themes will continue to progress unrelentingly no matter how refined it has now become.
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Affiliation(s)
- A V Rioux
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - T R Nsimba-Batomene
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S Slimani
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - N A D Bergeron
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M A M Gravel
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - S V Schreiber
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - M J Fiola
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
| | - L Haydock
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - A P Garneau
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
- Service de Néphrologie-Transplantation Rénale Adultes, Hôpital Necker-Enfants Malades, AP-HP, INSERM U1151, Université Paris Cité, Paris, France
| | - P Isenring
- Department of Medicine, Nephrology Research Group, Laval University, Quebec City, Quebec, Canada
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4
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Li HZ, Pike ACW, Lotsaris I, Chi G, Hansen JS, Lee SC, Rödström KEJ, Bushell SR, Speedman D, Evans A, Wang D, He D, Shrestha L, Nasrallah C, Burgess-Brown NA, Vandenberg RJ, Dafforn TR, Carpenter EP, Sauer DB. Structure and function of the SIT1 proline transporter in complex with the COVID-19 receptor ACE2. Nat Commun 2024; 15:5503. [PMID: 38951531 PMCID: PMC11217458 DOI: 10.1038/s41467-024-48921-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Accepted: 05/16/2024] [Indexed: 07/03/2024] Open
Abstract
Proline is widely known as the only proteogenic amino acid with a secondary amine. In addition to its crucial role in protein structure, the secondary amino acid modulates neurotransmission and regulates the kinetics of signaling proteins. To understand the structural basis of proline import, we solved the structure of the proline transporter SIT1 in complex with the COVID-19 viral receptor ACE2 by cryo-electron microscopy. The structure of pipecolate-bound SIT1 reveals the specific sequence requirements for proline transport in the SLC6 family and how this protein excludes amino acids with extended side chains. By comparing apo and substrate-bound SIT1 states, we also identify the structural changes that link substrate release and opening of the cytoplasmic gate and provide an explanation for how a missense mutation in the transporter causes iminoglycinuria.
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Affiliation(s)
- Huanyu Z Li
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Ashley C W Pike
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Irina Lotsaris
- Molecular Biomedicine Theme, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jesper S Hansen
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Sarah C Lee
- School of Biosciences, University of Birmingham, Birmingham, UK
| | - Karin E J Rödström
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Simon R Bushell
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - David Speedman
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Adam Evans
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Dong Wang
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Didi He
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Leela Shrestha
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Chady Nasrallah
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Robert J Vandenberg
- Molecular Biomedicine Theme, School of Medical Sciences, University of Sydney, Sydney, NSW, Australia.
| | | | - Elisabeth P Carpenter
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
| | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK.
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5
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Gelová Z, Ingles-Prieto A, Bohstedt T, Frommelt F, Chi G, Chang YN, Garcia J, Wolf G, Azzollini L, Tremolada S, Scacioc A, Hansen JS, Serrano I, Droce A, Bernal JC, Burgess-Brown NA, Carpenter EP, Dürr KL, Kristensen P, Geertsma ER, Štefanić S, Scarabottolo L, Wiedmer T, Puetter V, Sauer DB, Superti-Furga G. Protein Binder Toolbox for Studies of Solute Carrier Transporters. J Mol Biol 2024; 436:168665. [PMID: 38878854 DOI: 10.1016/j.jmb.2024.168665] [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: 03/05/2024] [Revised: 06/07/2024] [Accepted: 06/10/2024] [Indexed: 07/01/2024]
Abstract
Transporters of the solute carrier superfamily (SLCs) are responsible for the transmembrane traffic of the majority of chemical substances in cells and tissues and are therefore of fundamental biological importance. As is often the case with membrane proteins that can be heavily glycosylated, a lack of reliable high-affinity binders hinders their functional analysis. Purifying and reconstituting transmembrane proteins in their lipidic environments remains challenging and standard approaches to generate binders for multi-transmembrane proteins, such as SLCs, channels or G protein-coupled receptors (GPCRs) are lacking. While generating protein binders to 27 SLCs, we produced full length protein or cell lines as input material for binder generation by selected binder generation platforms. As a result, we obtained 525 binders for 22 SLCs. We validated the binders with a cell-based validation workflow using immunofluorescent and immunoprecipitation methods to process all obtained binders. Finally, we demonstrated the potential applications of the binders that passed our validation pipeline in structural, biochemical, and biological applications using the exemplary protein SLC12A6, an ion transporter relevant in human disease. With this work, we were able to generate easily renewable and highly specific binders against SLCs, which will greatly facilitate the study of this neglected protein family. We hope that the process will serve as blueprint for the generation of binders against the entire superfamily of SLC transporters.
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Affiliation(s)
- Zuzana Gelová
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Alvaro Ingles-Prieto
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Tina Bohstedt
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Fabian Frommelt
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Gamma Chi
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | | | - Julio Garcia
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Gernot Wolf
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | | | - Andreea Scacioc
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Jesper S Hansen
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Iciar Serrano
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | - Aida Droce
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | | | - Nicola A Burgess-Brown
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Elisabeth P Carpenter
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Katharina L Dürr
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Peter Kristensen
- Department of Chemistry and Bioscience, Aalborg University, Aalborg, Denmark
| | - Eric R Geertsma
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Saša Štefanić
- Nanobody Service Facility, University of Zurich, AgroVet-Strickhof, Eschikon, Switzerland
| | | | - Tabea Wiedmer
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria
| | | | - David B Sauer
- Centre for Medicines Discovery, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Giulio Superti-Furga
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Vienna, Austria; Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria.
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6
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Malik AJ, Langer D, Verma CS, Poole AM, Allison JR. Structome: a tool for the rapid assembly of datasets for structural phylogenetics. BIOINFORMATICS ADVANCES 2023; 3:vbad134. [PMID: 38046099 PMCID: PMC10692761 DOI: 10.1093/bioadv/vbad134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 08/17/2023] [Accepted: 09/29/2023] [Indexed: 12/05/2023]
Abstract
Summary Protein structures carry signal of common ancestry and can therefore aid in reconstructing their evolutionary histories. To expedite the structure-informed inference process, a web server, Structome, has been developed that allows users to rapidly identify protein structures similar to a query protein and to assemble datasets useful for structure-based phylogenetics. Structome was created by clustering ∼ 94 % of the structures in RCSB PDB using 90% sequence identity and representing each cluster by a centroid structure. Structure similarity between centroid proteins was calculated, and annotations from PDB, SCOP, and CATH were integrated. To illustrate utility, an H3 histone was used as a query, and results show that the protein structures returned by Structome span both sequence and structural diversity of the histone fold. Additionally, the pre-computed nexus-formatted distance matrix, provided by Structome, enables analysis of evolutionary relationships between proteins not identifiable using searches based on sequence similarity alone. Our results demonstrate that, beginning with a single structure, Structome can be used to rapidly generate a dataset of structural neighbours and allows deep evolutionary history of proteins to be studied. Availability and Implementation Structome is available at: https://structome.bii.a-star.edu.sg.
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Affiliation(s)
- Ashar J Malik
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 138671 Singapore
| | - Desiree Langer
- School of Biological Sciences, University of Auckland, 1142 Auckland, New Zealand
| | - Chandra S Verma
- Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), 138671 Singapore
- Department of Biological Sciences, National University of Singapore, 117543 Singapore
- School of Biological Sciences, Nanyang Technological University, 637551 Singapore
| | - Anthony M Poole
- School of Biological Sciences, University of Auckland, 1142 Auckland, New Zealand
- Digital Life Institute, University of Auckland, Auckland 1142, New Zealand
| | - Jane R Allison
- School of Biological Sciences, University of Auckland, 1142 Auckland, New Zealand
- Digital Life Institute, University of Auckland, Auckland 1142, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, 1142 Auckland, New Zealand
- Biomolecular Interaction Centre, University of Canterbury, 8041 Christchurch, New Zealand
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7
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Becker L, Hausmann J, Hartmann AM. Both chloride-binding sites are required for KCC2-mediated transport. J Biol Chem 2023; 299:105190. [PMID: 37625593 PMCID: PMC10518353 DOI: 10.1016/j.jbc.2023.105190] [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: 01/25/2023] [Revised: 07/30/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
The K+-Cl- cotransporter 2 (KCC2) plays an important role in inhibitory neurotransmission, and its impairment is associated with neurological and psychiatric disorders, including epilepsy, schizophrenia, and autism. Although KCCs transport K+ and Cl- in a 1:1 stoichiometry, two Cl- coordination sites were indicated via cryo-EM. In a comprehensive analysis, we analyzed the consequences of point mutations of residues coordinating Cl- in Cl1 and Cl2. Individual mutations of residues in Cl1 and Cl2 reduce or abolish KCC2WT function, indicating a crucial role of both Cl- coordination sites for KCC2 function. Structural changes in the extracellular loop 2 by inserting a 3xHA tag switches the K+ coordination site to another position. To investigate, whether the extension of the extracellular loop 2 with the 3xHA tag also affects the coordination of the two Cl- coordination sites, we carried out the analogous experiments for both Cl- coordinating sites in the KCC2HA construct. These analyses showed that most of the individual mutation of residues in Cl1 and Cl2 in the KCC2HA construct reduces or abolishes KCC2 function, indicating that the coordination of Cl- remains at the same position. However, the coupling of K+ and Cl- in Cl1 is still apparent in the KCC2HA construct, indicating a mutual dependence of both ions. In addition, the coordination residue Tyr569 in Cl2 shifted in KCC2HA. Thus, conformational changes in the extracellular domain affect K+ and Cl--binding sites. However, the effect on the Cl--binding sites is subtler.
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Affiliation(s)
- Lisa Becker
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Jens Hausmann
- Division of Anatomy, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
| | - Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany; Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany.
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8
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Trejo F, Elizalde S, Mercado A, Gamba G, de losHeros P. SLC12A cryo-EM: analysis of relevant ion binding sites, structural domains, and amino acids. Am J Physiol Cell Physiol 2023; 325:C921-C939. [PMID: 37545407 DOI: 10.1152/ajpcell.00089.2023] [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: 03/13/2023] [Revised: 07/24/2023] [Accepted: 07/24/2023] [Indexed: 08/08/2023]
Abstract
The solute carrier family 12A (SLC12A) superfamily of membrane transporters modulates the movement of cations coupled with chloride across the membrane. In doing so, these cotransporters are involved in numerous aspects of human physiology: cell volume regulation, ion homeostasis, blood pressure regulation, and neurological action potential via intracellular chloride concentration modulation. Their physiological characterization has been largely studied; however, understanding the mechanics of their function and the relevance of structural domains or specific amino acids has been a pending task. In recent years, single-particle cryogenic electron microscopy (cryo-EM) has been successfully applied to members of the SLC12A family including all K+:Cl- cotransporters (KCCs), Na+:K+:2Cl- cotransporter NKCC1, and recently Na+:Cl- cotransporter (NCC); revealing structural elements that play key roles in their function. The present review analyzes the data provided by these cryo-EM reports focusing on structural domains and specific amino acids involved in ion binding, domain interactions, and other important SCL12A structural elements. A comparison of cryo-EM data from NKCC1 and KCCs is presented in the light of the two recent NCC cryo-EM studies, to propose insight into structural elements that might also be found in NCC and are necessary for its proper function. In the final sections, the importance of key coordination residues for substrate specificity and their implication on various pathophysiological conditions and genetic disorders is reviewed, as this could provide the basis to correlate structural elements with the development of novel and selective treatments, as well as mechanistic insight into the function and regulation of cation-coupled chloride cotransporters (CCCs).
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Affiliation(s)
- Fátima Trejo
- Unidad de Investigación UNAM-INC, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Stephanie Elizalde
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | - Adriana Mercado
- Departamento de Bioquímica, Instituto Nacional de Cardiología Ignacio Chávez, Mexico City, Mexico
| | - Gerardo Gamba
- Departamento de Nefrología y Metabolismo Mineral, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
- Molecular Physiology Unit, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Paola de losHeros
- Unidad de Investigación UNAM-INC, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico
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9
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Flygaard RK, Habeck M, Nissen P. Technical Comment on "Inhibition mechanism of NKCC1 involves the carboxyl terminus and long-range conformational coupling". SCIENCE ADVANCES 2023; 9:eadh0821. [PMID: 37436990 DOI: 10.1126/sciadv.adh0821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Accepted: 06/08/2023] [Indexed: 07/14/2023]
Abstract
Flygaard, Habeck and Nissen question claims on bumetanide and furosemide binding to sodium-potassium-chloride cotransporter NKCC1.
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Affiliation(s)
- Rasmus Kock Flygaard
- Danish Research Institute of Translational Neuroscience (DANDRITE), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Michael Habeck
- Danish Research Institute of Translational Neuroscience (DANDRITE), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Poul Nissen
- Danish Research Institute of Translational Neuroscience (DANDRITE), Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
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10
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Moseng MA, Su CC, Klenotic PA, Delpire E, Yu EW. Response to Comment on "Inhibition mechanism of NKCC1 involves the carboxyl terminus and long-range conformational coupling". SCIENCE ADVANCES 2023; 9:eadi5716. [PMID: 37436983 DOI: 10.1126/sciadv.adi5716] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/07/2023] [Indexed: 07/14/2023]
Abstract
Moseng et al. recently reported four cryo-electron microscopy structures of the human Na-K-2Cl cotransporter-1 (hNKCC1), both in the absence and presence of bound loop diuretic (furosemide or bumetanide). This research article included high-resolution structural information for a previously undefined structure of apo-hNKCC1 containing both the transmembrane and cytosolic carboxyl-terminal domains. The manuscript also demonstrated various conformational states of this cotransporter induced by diuretic drugs. On the basis of the structural information, the authors proposed a scissor-like inhibition mechanism that involves a coupled movement between the cytosolic and transmembrane domains of hNKCC1. This work has provided important insights into the mechanism of inhibition and substantiated the concept of a long-distance coupling involving movements of both the transmembrane and carboxyl-terminal cytoplasmic domains for inhibition.
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Affiliation(s)
- Mitchell A Moseng
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Chih-Chia Su
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Philip A Klenotic
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Eric Delpire
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Edward W Yu
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
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11
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Fan M, Zhang J, Lee CL, Zhang J, Feng L. Structure and thiazide inhibition mechanism of the human Na-Cl cotransporter. Nature 2023; 614:788-793. [PMID: 36792826 PMCID: PMC10030352 DOI: 10.1038/s41586-023-05718-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 01/09/2023] [Indexed: 02/17/2023]
Abstract
The sodium-chloride cotransporter (NCC) is critical for kidney physiology1. The NCC has a major role in salt reabsorption in the distal convoluted tubule of the nephron2,3, and mutations in the NCC cause the salt-wasting disease Gitelman syndrome4. As a key player in salt handling, the NCC regulates blood pressure and is the target of thiazide diuretics, which have been widely prescribed as first-line medications to treat hypertension for more than 60 years5-7. Here we determined the structures of human NCC alone and in complex with a commonly used thiazide diuretic using cryo-electron microscopy. These structures, together with functional studies, reveal major conformational states of the NCC and an intriguing regulatory mechanism. They also illuminate how thiazide diuretics specifically interact with the NCC and inhibit its transport function. Our results provide critical insights for understanding the Na-Cl cotransport mechanism of the NCC, and they establish a framework for future drug design and for interpreting disease-related mutations.
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Affiliation(s)
- Minrui Fan
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jianxiu Zhang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Chien-Ling Lee
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Jinru Zhang
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA
| | - Liang Feng
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA, USA.
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12
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Zhao Y, Cao E. Structural Pharmacology of Cation-Chloride Cotransporters. MEMBRANES 2022; 12:1206. [PMID: 36557113 PMCID: PMC9784483 DOI: 10.3390/membranes12121206] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 06/17/2023]
Abstract
Loop and thiazide diuretics have been cornerstones of clinical management of hypertension and fluid overload conditions for more than five decades. The hunt for their molecular targets led to the discovery of cation-chloride cotransporters (CCCs) that catalyze electroneutral movement of Cl- together with Na+ and/or K+. CCCs consist of two 1 Na+-1 K+-2 Cl- (NKCC1-2), one 1 Na+-1 Cl- (NCC), and four 1 K+-1 Cl- (KCC1-4) transporters in human. CCCs are fundamental in trans-epithelia ion secretion and absorption, homeostasis of intracellular Cl- concentration and cell volume, and regulation of neuronal excitability. Malfunction of NKCC2 and NCC leads to abnormal salt and water retention in the kidney and, consequently, imbalance in electrolytes and blood pressure. Mutations in KCC2 and KCC3 are associated with brain disorders due to impairments in regulation of excitability and possibly cell volume of neurons. A recent surge of structures of CCCs have defined their dimeric architecture, their ion binding sites, their conformational changes associated with ion translocation, and the mechanisms of action of loop diuretics and small molecule inhibitors. These breakthroughs now set the stage to expand CCC pharmacology beyond loop and thiazide diuretics, developing the next generation of diuretics with improved potency and specificity. Beyond drugging renal-specific CCCs, brain-penetrable therapeutics are sorely needed to target CCCs in the nervous system for the treatment of neurological disorders and psychiatric conditions.
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13
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Nan J, Yuan Y, Yang X, Shan Z, Liu H, Wei F, Zhang W, Zhang Y. Cryo-EM structure of the human sodium-chloride cotransporter NCC. SCIENCE ADVANCES 2022; 8:eadd7176. [PMID: 36351028 PMCID: PMC9645730 DOI: 10.1126/sciadv.add7176] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/21/2022] [Indexed: 05/29/2023]
Abstract
The sodium-chloride cotransporter NCC mediates the coupled import of sodium and chloride across the plasma membrane, playing vital roles in kidney extracellular fluid volume and blood pressure control. Here, we present the full-length structure of human NCC, with 2.9 Å for the transmembrane domain and 3.8 Å for the carboxyl-terminal domain. NCC adopts an inward-open conformation and a domain-swap dimeric assembly. Conserved ion binding sites among the cation-chloride cotransporters and the Na2 site are observed in our structure. A unique His residue in the substrate pocket in NCC potentially interacts with Na1 and Cl1 and might also mediate the coordination of Na2 through a Ser residue. Putative observed water molecules are indicated to participate in the coordination of ions and TM coupling. Together with transport activity assays, our structure provides the first glimpse of NCC and defines ion binding sites, promoting drug development for hypertension targeting on NCC.
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Affiliation(s)
- Jing Nan
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yafei Yuan
- Beijing Frontier Research Center for Biological Structure, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing 100084, China
| | - Xuemei Yang
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Ziyang Shan
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Huihui Liu
- Warshel Institute for Computational Biology, School of Life and Health Sciences, The Chinese University of Hong Kong, Shenzhen 518172, Guangdong, China
| | - Feiwen Wei
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Wei Zhang
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
| | - Yanqing Zhang
- Shanghai Fifth People’s Hospital, Fudan University, and Shanghai Key Laboratory of Medical Epigenetics, International Co-laboratory of Medical Epigenetics and Metabolism (Ministry of Science and Technology), Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, China
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14
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Neumann C, Rosenbæk LL, Flygaard RK, Habeck M, Karlsen JL, Wang Y, Lindorff‐Larsen K, Gad HH, Hartmann R, Lyons JA, Fenton RA, Nissen P. Cryo-EM structure of the human NKCC1 transporter reveals mechanisms of ion coupling and specificity. EMBO J 2022; 41:e110169. [PMID: 36239040 PMCID: PMC9713717 DOI: 10.15252/embj.2021110169] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 12/03/2022] Open
Abstract
The sodium-potassium-chloride transporter NKCC1 of the SLC12 family performs Na+ -dependent Cl- - and K+ -ion uptake across plasma membranes. NKCC1 is important for regulating cell volume, hearing, blood pressure, and regulation of hyperpolarizing GABAergic and glycinergic signaling in the central nervous system. Here, we present a 2.6 Å resolution cryo-electron microscopy structure of human NKCC1 in the substrate-loaded (Na+ , K+ , and 2 Cl- ) and occluded, inward-facing state that has also been observed for the SLC6-type transporters MhsT and LeuT. Cl- binding at the Cl1 site together with the nearby K+ ion provides a crucial bridge between the LeuT-fold scaffold and bundle domains. Cl- -ion binding at the Cl2 site seems to undertake a structural role similar to conserved glutamate of SLC6 transporters and may allow for Cl- -sensitive regulation of transport. Supported by functional studies in mammalian cells and computational simulations, we describe a putative Na+ release pathway along transmembrane helix 5 coupled to the Cl2 site. The results provide insight into the structure-function relationship of NKCC1 with broader implications for other SLC12 family members.
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Affiliation(s)
- Caroline Neumann
- Danish Research Institute of Translational Neuroscience—DANDRITENordic EMBL Partnership for Molecular MedicineAarhusDenmark,Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | | | - Rasmus Kock Flygaard
- Danish Research Institute of Translational Neuroscience—DANDRITENordic EMBL Partnership for Molecular MedicineAarhusDenmark,Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Michael Habeck
- Danish Research Institute of Translational Neuroscience—DANDRITENordic EMBL Partnership for Molecular MedicineAarhusDenmark,Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | | | - Yong Wang
- Linderstrøm‐Lang Centre for Protein Science, Department of BiologyUniversity of CopenhagenCopenhagenDenmark,Shanghai Institute for Advanced Study, Institute of Quantitative Biology, College of Life SciencesZhejiang UniversityHangzhouChina
| | - Kresten Lindorff‐Larsen
- Linderstrøm‐Lang Centre for Protein Science, Department of BiologyUniversity of CopenhagenCopenhagenDenmark
| | - Hans Henrik Gad
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Rune Hartmann
- Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
| | - Joseph Anthony Lyons
- Danish Research Institute of Translational Neuroscience—DANDRITENordic EMBL Partnership for Molecular MedicineAarhusDenmark,Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark,Interdisciplinary Nanoscience Center (iNANO)Aarhus UniversityAarhusDenmark
| | | | - Poul Nissen
- Danish Research Institute of Translational Neuroscience—DANDRITENordic EMBL Partnership for Molecular MedicineAarhusDenmark,Department of Molecular Biology and GeneticsAarhus UniversityAarhusDenmark
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15
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Hartmann AM, Nothwang HG. NKCC1 and KCC2: Structural insights into phospho-regulation. Front Mol Neurosci 2022; 15:964488. [PMID: 35935337 PMCID: PMC9355526 DOI: 10.3389/fnmol.2022.964488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/06/2022] [Indexed: 11/13/2022] Open
Abstract
Inhibitory neurotransmission plays a fundamental role in the central nervous system, with about 30–50% of synaptic connections being inhibitory. The action of both inhibitory neurotransmitter, gamma-aminobutyric-acid (GABA) and glycine, mainly relies on the intracellular Cl– concentration in neurons. This is set by the interplay of the cation chloride cotransporters NKCC1 (Na+, K+, Cl– cotransporter), a main Cl– uptake transporter, and KCC2 (K+, Cl– cotransporter), the principle Cl– extruder in neurons. Accordingly, their dysfunction is associated with severe neurological, psychiatric, and neurodegenerative disorders. This has triggered great interest in understanding their regulation, with a strong focus on phosphorylation. Recent structural data by cryogenic electron microscopy provide the unique possibility to gain insight into the action of these phosphorylations. Interestingly, in KCC2, six out of ten (60%) known regulatory phospho-sites reside within a region of 134 amino acid residues (12% of the total residues) between helices α8 and α9 that lacks fixed or ordered three-dimensional structures. It thus represents a so-called intrinsically disordered region. Two further phospho-sites, Tyr903 and Thr906, are also located in a disordered region between the ß8 strand and the α8 helix. We make the case that especially the disordered region between helices α8 and α9 acts as a platform to integrate different signaling pathways and simultaneously constitute a flexible, highly dynamic linker that can survey a wide variety of distinct conformations. As each conformation can have distinct binding affinities and specificity properties, this enables regulation of [Cl–]i and thus the ionic driving force in a history-dependent way. This region might thus act as a molecular processor underlying the well described phenomenon of ionic plasticity that has been ascribed to inhibitory neurotransmission. Finally, it might explain the stunning long-range effects of mutations on phospho-sites in KCC2.
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Affiliation(s)
- Anna-Maria Hartmann
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- *Correspondence: Anna-Maria Hartmann,
| | - Hans Gerd Nothwang
- Division of Neurogenetics, School of Medicine and Health Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
- Center of Excellence Hearing4all, Carl von Ossietzky University Oldenburg, Oldenburg, Germany
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16
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Zhao Y, Shen J, Wang Q, Ruiz Munevar MJ, Vidossich P, De Vivo M, Zhou M, Cao E. Structure of the human cation-chloride cotransport KCC1 in an outward-open state. Proc Natl Acad Sci U S A 2022; 119:e2109083119. [PMID: 35759661 PMCID: PMC9271165 DOI: 10.1073/pnas.2109083119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 04/25/2022] [Indexed: 12/30/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) catalyze electroneutral symport of Cl- with Na+ and/or K+ across membranes. CCCs are fundamental in cell volume homeostasis, transepithelia ion movement, maintenance of intracellular Cl- concentration, and neuronal excitability. Here, we present a cryoelectron microscopy structure of human K+-Cl- cotransporter (KCC)1 bound with the VU0463271 inhibitor in an outward-open state. In contrast to many other amino acid-polyamine-organocation transporter cousins, our first outward-open CCC structure reveals that opening the KCC1 extracellular ion permeation path does not involve hinge-bending motions of the transmembrane (TM) 1 and TM6 half-helices. Instead, rocking of TM3 and TM8, together with displacements of TM4, TM9, and a conserved intracellular loop 1 helix, underlie alternate opening and closing of extracellular and cytoplasmic vestibules. We show that KCC1 intriguingly exists in one of two distinct dimeric states via different intersubunit interfaces. Our studies provide a blueprint for understanding the mechanisms of CCCs and their inhibition by small molecule compounds.
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Affiliation(s)
- Yongxiang Zhao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | - Jiemin Shen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Qinzhe Wang
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
| | | | | | - Marco De Vivo
- Istituto Italiano di Tecnologia, 16163 Genova, Italy
| | - Ming Zhou
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030
| | - Erhu Cao
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112
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17
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Structural basis for inhibition of the Cation-chloride cotransporter NKCC1 by the diuretic drug bumetanide. Nat Commun 2022; 13:2747. [PMID: 35585053 PMCID: PMC9117670 DOI: 10.1038/s41467-022-30407-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 04/28/2022] [Indexed: 11/08/2022] Open
Abstract
Cation-chloride cotransporters (CCCs) NKCC1 and NKCC2 catalyze electroneutral symport of 1 Na+, 1 K+, and 2 Cl− across cell membranes. NKCC1 mediates trans-epithelial Cl− secretion and regulates excitability of some neurons and NKCC2 is critical to renal salt reabsorption. Both transporters are inhibited by the so-called loop diuretics including bumetanide, and these drugs are a mainstay for treating edema and hypertension. Here, our single-particle electron cryo-microscopy structures supported by functional studies reveal an outward-facing conformation of NKCC1, showing bumetanide wedged into a pocket in the extracellular ion translocation pathway. Based on these and the previously published inward-facing structures, we define the translocation pathway and the conformational changes necessary for ion translocation. We also identify an NKCC1 dimer with separated transmembrane domains and extensive transmembrane and C-terminal domain interactions. We further define an N-terminal phosphoregulatory domain that interacts with the C-terminal domain, suggesting a mechanism whereby (de)phosphorylation regulates NKCC1 by tuning the strength of this domain association. Loop diuretics including bumetanide inhibit Na+-K+-Cl−-cotransporters (NKCCs) and are used for the treatment of edema and hypertension. Here, Zhao et. al. report structures of NKCC1 with bumetanide bound, revealing its mechanism of action that would facilitate design of novel diuretics.
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18
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Löscher W, Kaila K. CNS pharmacology of NKCC1 inhibitors. Neuropharmacology 2021; 205:108910. [PMID: 34883135 DOI: 10.1016/j.neuropharm.2021.108910] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 12/21/2022]
Abstract
The Na-K-2Cl cotransporter NKCC1 and the neuron-specific K-Cl cotransporter KCC2 are considered attractive CNS drug targets because altered neuronal chloride regulation and consequent effects on GABAergic signaling have been implicated in numerous CNS disorders. While KCC2 modulators are not yet clinically available, the loop diuretic bumetanide has been used off-label in attempts to treat brain disorders and as a tool for NKCC1 inhibition in preclinical models. Bumetanide is known to have anticonvulsant and neuroprotective effects under some pathophysiological conditions. However, as shown in several species from neonates to adults (mice, rats, dogs, and by extrapolation in humans), at the low clinical doses of bumetanide approved for diuresis, this drug has negligible access into the CNS, reaching levels that are much lower than what is needed to inhibit NKCC1 in cells within the brain parenchyma. Several drug discovery strategies have been initiated over the last ∼15 years to develop brain-permeant compounds that, ideally, should be selective for NKCC1 to eliminate the diuresis mediated by inhibition of renal NKCC2. The strategies employed to improve the pharmacokinetic and pharmacodynamic properties of NKCC1 blockers include evaluation of other clinically approved loop diuretics; development of lipophilic prodrugs of bumetanide; development of side-chain derivatives of bumetanide; and unbiased high-throughput screening approaches of drug discovery based on large chemical compound libraries. The main outcomes are that (1), non-acidic loop diuretics such as azosemide and torasemide may have advantages as NKCC1 inhibitors vs. bumetanide; (2), bumetanide prodrugs lead to significantly higher brain levels than the parent drug and have lower diuretic activity; (3), the novel bumetanide side-chain derivatives do not exhibit any functionally relevant improvement of CNS accessibility or NKCC1 selectivity vs. bumetanide; (4) novel compounds discovered by high-throughput screening may resolve some of the inherent problems of bumetanide, but as yet this has not been achieved. Thus, further research is needed to optimize the design of brain-permeant NKCC1 inhibitors. In parallel, a major challenge is to identify the mechanisms whereby various NKCC1-expressing cellular targets of these drugs within (e.g., neurons, oligodendrocytes or astrocytes) and outside the brain parenchyma (e.g., the blood-brain barrier, the choroid plexus, and the endocrine system), as well as molecular off-target effects, might contribute to their reported therapeutic and adverse effects.
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Affiliation(s)
- Wolfgang Löscher
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
| | - Kai Kaila
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Finland
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19
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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] [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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20
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Kock Flygaard R, Neumann C, Anthony Lyons J, Nissen P. Transport unplugged: KCCs are regulated through an N-terminal plug of the ion pathway. EMBO J 2021; 40:e108371. [PMID: 34031898 DOI: 10.15252/embj.2021108371] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 04/12/2021] [Indexed: 01/06/2023] Open
Abstract
The ability to regulate transmembrane ion transport in response to various cues is vital to any living cell. In neurons, one key example of critical ion control relates to the extrusion of chloride mediated by the potassium-chloride-cotransporters (KCC1-4). In a recent hallmark study, Chi et␣al (2021) report cryo-EM structures of human KCC1 and KCC3b, delineating in detail how regulation by phosphorylation inhibits the transport activity. The authors also identify a stabilizing binding site for nucleotides and speculate on its functional role.
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Affiliation(s)
- Rasmus Kock Flygaard
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Caroline Neumann
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Joseph Anthony Lyons
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
| | - Poul Nissen
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, Aarhus, Denmark
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