1
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Okada Y. Physiology of the volume-sensitive/regulatory anion channel VSOR/VRAC. Part 1: from its discovery and phenotype characterization to the molecular entity identification. J Physiol Sci 2024; 74:3. [PMID: 38238667 PMCID: PMC10795261 DOI: 10.1186/s12576-023-00897-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 12/27/2023] [Indexed: 01/22/2024]
Abstract
The volume-sensitive outwardly rectifying or volume-regulated anion channel, VSOR/VRAC, which was discovered in 1988, is expressed in most vertebrate cell types and is essentially involved in cell volume regulation after swelling and in the induction of cell death. This series of review articles describes what is already known and what remains to be uncovered about the functional and molecular properties as well as the physiological and pathophysiological roles of VSOR/VRAC. This Part 1 review article describes, from the physiological standpoint, first its discovery and significance in cell volume regulation, second its phenotypical properties, and third its molecular identification. Although the pore-forming core molecules and the volume-sensing subcomponent of VSOR/VRAC were identified as LRRC8 members and TRPM7 in 2014 and 2021, respectively, it is stressed that the identification of the molecular entity of VSOR/VRAC is still not complete enough to explain the full set of phenotypical properties.
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Affiliation(s)
- Yasunobu Okada
- National Institute for Physiological Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi, 444-8787, Japan.
- Department of Integrative Physiology, Graduate School of Medicine, Akita University, Akita, Japan.
- Department of Physiology, School of Medicine, Aichi Medical University, Nagakute, Japan.
- Department of Physiology, Kyoto Prefectural University of Medicine, Kyoto, Japan.
- Cardiovascular Research Institute, Yokohama City University, Yokohama, Japan.
- Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.
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2
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Kostritskaia Y, Klüssendorf M, Pan YE, Hassani Nia F, Kostova S, Stauber T. Physiological Functions of the Volume-Regulated Anion Channel VRAC/LRRC8 and the Proton-Activated Chloride Channel ASOR/TMEM206. Handb Exp Pharmacol 2024; 283:181-218. [PMID: 37468723 DOI: 10.1007/164_2023_673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Volume-regulated anion channels (VRACs) and the acid-sensitive outwardly rectifying anion channel (ASOR) mediate flux of chloride and small organic anions. Although known for a long time, they were only recently identified at the molecular level. VRACs are heteromers consisting of LRRC8 proteins A to E. Combining the essential LRRC8A with different LRRC8 paralogues changes key properties of VRAC such as conductance or substrate selectivity, which is how VRACs are involved in multiple physiological functions including regulatory volume decrease, cell proliferation and migration, cell death, purinergic signalling, fat and glucose metabolism, insulin signalling, and spermiogenesis. VRACs are also involved in pathological conditions, such as the neurotoxic release of glutamate and aspartate. Certain VRACs are also permeable to larger, organic anions, including antibiotics and anti-cancer drugs, making them an interesting therapeutic target. ASOR, also named proton-activated chloride channel (PAC), is formed by TMEM206 homotrimers on the plasma membrane and on endosomal compartments where it mediates chloride flux in response to extracytosolic acidification and plays a role in the shrinking and maturation of macropinosomes. ASOR has been shown to underlie neuronal swelling which causes cell death after stroke as well as promoting the metastasis of certain cancers, making them intriguing therapeutic targets as well.
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Affiliation(s)
- Yulia Kostritskaia
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Malte Klüssendorf
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Yingzhou Edward Pan
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Fatemeh Hassani Nia
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Simona Kostova
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Tobias Stauber
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany.
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3
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Liu T, Li Y, Wang D, Stauber T, Zhao J. Trends in volume-regulated anion channel (VRAC) research: visualization and bibliometric analysis from 2014 to 2022. Front Pharmacol 2023; 14:1234885. [PMID: 37538172 PMCID: PMC10394876 DOI: 10.3389/fphar.2023.1234885] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 07/10/2023] [Indexed: 08/05/2023] Open
Abstract
Objective: In this study, we utilized bibliometric methods to assess the worldwide scientific output and identify hotspots related to the research on the volume-regulated anion channel (VRAC) from 2014 to 2022. Methods: From Web of Science, we obtained studies related to VRAC published from 2014 to 2022. To analyzed the data, we utilized VOSviewer, a tool for visualizing network, to create networks based on the collaboration between countries, institutions, and authors. Additionally, we performed an analysis of journal co-citation, document citation, and co-occurrence of keywords. Furthermore, we employed CiteSpace (6.1. R6 Advanced) to analyzed keywords and co-cited references with the strongest burst. Results: The final analysis included a total of 278 related articles and reviews, covering the period from 2014 to 2022. The United States emerged as the leading country contributing to this field, while the University of Copenhagen stood out as the most prominent institution. The author with most publications and most citations was Thomas J. Jentsch. Among the cited references, the article by Voss et al. published in Science (2014) gained significant attention for its identification of LRRC8 heteromers as a crucial component of the volume-regulated anion channel VRAC. Pflügers Archiv European Journal of Physiology and Journal of Physiology-London were the leading journals in terms of the quantity of associated articles and citations. Through the analysis of keyword co-occurrence, it was discovered that VRAC is involved in various physiological processes including cell growth, migration, apoptosis, swelling, and myogenesis, as well as anion and organic osmolyte transport including chloride, taurine, glutamate and ATP. VRAC is also associated with related ion channels such as TMEM16A, TMEM16F, pannexin, and CFTR, and associated with various diseases including epilepsy, leukodystrophy, atherosclerosis, hypertension, cerebral edema, stroke, and different types of cancer including gastric cancer, glioblastoma and hepatocellular carcinoma. Furthermore, VRAC is involved in anti-tumor drug resistance by regulating the uptake of platinum-based drugs and temozolomide. Additionally, VRAC has been studied in the context of pharmacology involving DCPIB and flavonoids. Conclusion: The aim of this bibliometric analysis is to provide an overall perspective for research on VRAC. VRAC has become a topic of increasing interest, and our analysis shows that it continues to be a prominent area. This study offers insights into the investigation of VRAC channel and may guide researchers in identifying new directions for future research.
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Affiliation(s)
- Tianbao Liu
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
| | - Yin Li
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Shandong Provincial Hospital, Jinan, Shandong, China
| | - Dawei Wang
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
- Department of Endocrinology, Shandong Provincial Hospital, Shandong University, Jinan, Shandong, China
| | - Tobias Stauber
- Institute for Molecular Medicine, MSH Medical School Hamburg, Hamburg, Germany
| | - Jiajun Zhao
- Key Laboratory of Endocrine Glucose & Lipids Metabolism and Brain Aging, Ministry of Education, Department of Endocrinology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, China
- Shandong Key Laboratory of Endocrinology and Lipid Metabolism, Jinan, Shandong, China
- Shandong Institute of Endocrine and Metabolic Disease, Jinan, Shandong, China
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4
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Kumar V, Bauer C, Stewart JH. Targeting cGAS/STING signaling-mediated myeloid immune cell dysfunction in TIME. J Biomed Sci 2023; 30:48. [PMID: 37380989 PMCID: PMC10304357 DOI: 10.1186/s12929-023-00942-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Accepted: 06/14/2023] [Indexed: 06/30/2023] Open
Abstract
Myeloid immune cells (MICs) are potent innate immune cells serving as first responders to invading pathogens and internal changes to cellular homeostasis. Cancer is a stage of altered cellular homeostasis that can originate in response to different pathogens, chemical carcinogens, and internal genetic/epigenetic changes. MICs express several pattern recognition receptors (PRRs) on their membranes, cytosol, and organelles, recognizing systemic, tissue, and organ-specific altered homeostasis. cGAS/STING signaling is a cytosolic PRR system for identifying cytosolic double-stranded DNA (dsDNA) in a sequence-independent but size-dependent manner. The longer the cytosolic dsDNA size, the stronger the cGAS/STING signaling activation with increased type 1 interferon (IFN) and NF-κB-dependent cytokines and chemokines' generation. The present article discusses tumor-supportive changes occurring in the tumor microenvironment (TME) or tumor immune microenvironment (TIME) MICs, specifically emphasizing cGAS/STING signaling-dependent alteration. The article further discusses utilizing MIC-specific cGAS/STING signaling modulation as critical tumor immunotherapy to alter TIME.
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Affiliation(s)
- Vijay Kumar
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
| | - Caitlin Bauer
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA
| | - John H Stewart
- Department of Interdisciplinary Oncology, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
- Louisiana Children's Medical Center Cancer Center, Stanley S. Scott Cancer Center, School of Medicine, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
- Surgery, Section of Surgical Oncology, Louisiana State University New Orleans-Louisiana Children's Medical Center Cancer Center, Louisiana State University Health Science Center (LSUHSC), 1700 Tulane Avenue, New Orleans, LA, 70012, USA.
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5
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Kern DM, Bleier J, Mukherjee S, Hill JM, Kossiakoff AA, Isacoff EY, Brohawn SG. Structural basis for assembly and lipid-mediated gating of LRRC8A:C volume-regulated anion channels. Nat Struct Mol Biol 2023:10.1038/s41594-023-00944-6. [PMID: 36928458 DOI: 10.1038/s41594-023-00944-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 02/22/2023] [Indexed: 03/18/2023]
Abstract
Leucine-rich repeat-containing protein 8 (LRRC8) family members form volume-regulated anion channels activated by hypoosmotic cell swelling. LRRC8 channels are ubiquitously expressed in vertebrate cells as heteromeric assemblies of LRRC8A (SWELL1) and LRRC8B-E subunits. Channels of different subunit composition have distinct properties that explain the functional diversity of LRRC8 currents across cell types. However, the basis for heteromeric LRRC8 channel assembly and function is unknown. Here we leverage a fiducial-tagging strategy to determine single-particle cryo-EM structures of heterohexameric LRRC8A:C channels in multiple conformations. Compared to homomers, LRRC8A:C channels show pronounced differences in architecture due to heterotypic LRR interactions that displace subunits away from the conduction axis and poise the channel for activation. Structures and functional studies further reveal that lipids embedded in the channel pore block ion conduction in the closed state. These results provide insight into determinants for heteromeric LRRC8 channel assembly, activity and gating by lipids.
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Affiliation(s)
- David M Kern
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA, USA
| | - Julia Bleier
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - Somnath Mukherjee
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.,Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - Jennifer M Hill
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA
| | - Anthony A Kossiakoff
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA.,Institute for Biophysical Dynamics, University of Chicago, Chicago, IL, USA
| | - Ehud Y Isacoff
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA.,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA.,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA, USA
| | - Stephen G Brohawn
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA. .,Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA. .,California Institute for Quantitative Biology (QB3), University of California, Berkeley, CA, USA.
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6
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Zhang J, Toremurat Z, Liang Y, Cheng J, Sun Z, Huang Y, Liu J, Chaogetu BUREN, Ren G, Chen H. Study on the Association between LRRC8B Gene InDel and Sheep Body Conformation Traits. Genes (Basel) 2023; 14:genes14020356. [PMID: 36833283 PMCID: PMC9956668 DOI: 10.3390/genes14020356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 12/23/2022] [Accepted: 01/16/2023] [Indexed: 01/31/2023] Open
Abstract
Marker-assisted selection is an important method for livestock breeding. In recent years, this technology has been gradually applied to livestock breeding to improve the body conformation traits. In this study, the LRRC8B (Leucine Rich Repeat Containing 8 VRAC Subunit B) gene was selected to evaluate the association between its genetic variations and the body conformation traits in two native sheep breeds in China. Four body conformation traits, including withers height, body length, chest circumference, and body weight, were collected from 269 Chaka sheep. We also collected the body length, chest width, withers height, chest depth, chest circumference, cannon bone circumference, and height at hip cross of 149 Small-Tailed Han sheep. Two different genotypes, ID and DD, were detected in all sheep. Our data showed that the polymorphism of the LRRC8B gene was significantly associated with chest depth (p < 0.05) in Small-Tailed Han sheep, and it is greater in sheep with DD than those with ID. In conclusion, our data suggested that the LRRC8B gene could serve as a candidate gene for marker-assisted selection in Small-Tailed Han sheep.
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Affiliation(s)
- Jiaqiang Zhang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Zhansaya Toremurat
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Yilin Liang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Jie Cheng
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Zhenzhen Sun
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Yangming Huang
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
| | - Junxia Liu
- College of Life Sciences, Northwest A&F University, Xianyang 712100, China
| | - BUREN Chaogetu
- Animal Disease Control Center of Haixi Mongolian and Tibetan Autonomous Prefecture, Delingha 817000, China
| | - Gang Ren
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
- Correspondence: (G.R.); (H.C.); Tel.: +86-029-87092102 (H.C.); Fax: +86-029-87092164 (H.C.)
| | - Hong Chen
- Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Xianyang 712100, China
- College of Animal Science, Xinjiang Agricultural University, Urumqi 830052, China
- Correspondence: (G.R.); (H.C.); Tel.: +86-029-87092102 (H.C.); Fax: +86-029-87092164 (H.C.)
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7
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Rutz S, Deneka D, Dittmann A, Sawicka M, Dutzler R. Structure of a volume-regulated heteromeric LRRC8A/C channel. Nat Struct Mol Biol 2023; 30:52-61. [PMID: 36522427 PMCID: PMC9851909 DOI: 10.1038/s41594-022-00899-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/15/2022] [Indexed: 12/23/2022]
Abstract
Volume-regulated anion channels (VRACs) participate in the cellular response to osmotic swelling. These membrane proteins consist of heteromeric assemblies of LRRC8 subunits, whose compositions determine permeation properties. Although structures of the obligatory LRRC8A, also referred to as SWELL1, have previously defined the architecture of VRACs, the organization of heteromeric channels has remained elusive. Here we have addressed this question by the structural characterization of murine LRRC8A/C channels. Like LRRC8A, these proteins assemble as hexamers. Despite 12 possible arrangements, we find a predominant organization with an A:C ratio of two. In this assembly, four LRRC8A subunits cluster in their preferred conformation observed in homomers, as pairs of closely interacting proteins that stabilize a closed state of the channel. In contrast, the two interacting LRRC8C subunits show a larger flexibility, underlining their role in the destabilization of the tightly packed A subunits, thereby enhancing the activation properties of the protein.
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Affiliation(s)
- Sonja Rutz
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Dawid Deneka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | | | - Marta Sawicka
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
| | - Raimund Dutzler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.
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8
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Ghouli MR, Fiacco TA, Binder DK. Structure-function relationships of the LRRC8 subunits and subdomains of the volume-regulated anion channel (VRAC). Front Cell Neurosci 2022; 16:962714. [PMID: 36035259 PMCID: PMC9399500 DOI: 10.3389/fncel.2022.962714] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 07/18/2022] [Indexed: 11/19/2022] Open
Abstract
Volume Regulated Anion Channels (VRAC) are critical contributors to cell volume homeostasis and are expressed ubiquitously in all vertebrate cells. VRAC sense increases in cell volume, and act to return cells to baseline volume in a process known as regulatory volume decrease (RVD) through the efflux of anions and organic osmolytes. This review will highlight seminal studies that elucidated the role of VRAC in RVD, their characteristics as a function of subunit specificity, and their clinical relevance in physiology and pathology. VRAC are also known as volume-sensitive outward rectifiers (VSOR) and volume-sensitive organic osmolyte/anion channels (VSOAC). In this review, the term VRAC will be used to refer to this family of channels.
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Affiliation(s)
- Manolia R. Ghouli
- Division of Biomedical Sciences, School of Medicine, University of California–Riverside, Riverside, CA, United States
| | - Todd A. Fiacco
- Department of Cell Biology and Neuroscience, Center for Glial-Neuronal Interactions, University of California–Riverside, Riverside, CA, United States
| | - Devin K. Binder
- Division of Biomedical Sciences, School of Medicine, University of California–Riverside, Riverside, CA, United States
- *Correspondence: Devin K. Binder
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9
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Sawicka M, Dutzler R. Regulators of cell volume: The structural and functional properties of anion channels of the LRRC8 family. Curr Opin Struct Biol 2022; 74:102382. [DOI: 10.1016/j.sbi.2022.102382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 11/03/2022]
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10
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Kasuya G, Nureki O. Recent Advances in the Structural Biology of the Volume-Regulated Anion Channel LRRC8. Front Pharmacol 2022; 13:896532. [PMID: 35645818 PMCID: PMC9130832 DOI: 10.3389/fphar.2022.896532] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 04/25/2022] [Indexed: 01/23/2023] Open
Abstract
Members of the leucine-rich repeat-containing 8 (LRRC8) protein family, composed of five LRRC8A-E isoforms, are pore-forming components of the volume-regulated anion channel (VRAC), which is activated by cell swelling and releases chloride ions (Cl−) or other osmolytes to counteract cell swelling. Although the LRRC8 protein family was identified as the molecular entity of VRAC only in 2014, due to recent advances in cryo-electron microscopy (cryo-EM), various LRRC8 structures, including homo-hexameric LRRC8A and LRRC8D structures, as well as inhibitor-bound and synthetic single-domain antibody-bound homo-hexameric LRRC8A structures, have been reported, thus extending our understanding of the molecular mechanisms of this protein family. In this review, we describe the important features of LRRC8 provided by these structures, particularly the overall architectures, and the suggested mechanisms underlying pore inhibition and allosteric modulation by targeting the intracellular leucine-rich repeat (LRR) domain.
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Affiliation(s)
- Go Kasuya
- Division of Integrative Physiology, Department of Physiology, Jichi Medical University, Shimotsuke, Japan
- *Correspondence: Go Kasuya, ; Osamu Nureki,
| | - Osamu Nureki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
- *Correspondence: Go Kasuya, ; Osamu Nureki,
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11
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Wang Z, Li Y, Zeng Z, Guo S, Chen W, Luo Y. Leucine-rich repeat containing 8A contributes to the expansion of The potential role of leucine-rich repeat-containing protein 8A in central nervous system: current situation and prospect. Neuroscience 2022; 488:122-131. [PMID: 35276302 DOI: 10.1016/j.neuroscience.2022.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/24/2022] [Accepted: 03/01/2022] [Indexed: 12/12/2022]
Abstract
Cell swelling usually initiates the regulatory volume decrease (RVD) process mediated mainly by volume-regulated anion channels (VRACs), which are formed by multiple different leucine-rich repeat-containing protein 8 (LRRC8) family members. VRAC currents have been widely recorded in astrocytes, neurons and microglia in the brain, and VRACs have been suggested to be involved in the important pathogenesis of cell swelling-related central nervous system (CNS) diseases, such as ischemic stroke, epilepsy and epileptogenesis, glioblastoma (GBM), and so on. Recently, the increasing studies started to focus on LRRC8A (SWELL1), an obligatory subunit of VRAC indentified in 2014, which may be the key target to regulate the VRAC functions. After cerebral ischemia, the swollen astrocytes, neurons and microglia can activate LRRC8A-dependent VRACs, which may respectively promote the release of excitatory amino acids (EAA), interaction with ionotropic glutamate receptors, and regulating inflammation, suggesting the pleiotropic roles of LRRC8A in swollen brain cells. For the treatment of cell swelling-related CNS diseases, specific targeting LRRC8A may be a superior strategy to inhibit swollen-induced VRAC hyperactivity without blocking the normal VRAC function.
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Affiliation(s)
- Zhuo Wang
- Department of Neurology, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China; Wuhan Institute for Neuroscience and Neuroengineering, South-Central University for Nationalities, Wuhan 430074, Hubei, China
| | - Yunhui Li
- National Key Laboratory of Medical Immunology & Institute of Immunology, Second Military Medical University, Shanghai 200433, China
| | - Zhikun Zeng
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China
| | - Shuang Guo
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China
| | - Wei Chen
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China
| | - Yi Luo
- Department of Laboratory Medicine, Zhongnan Hospital of Wuhan University, Wuhan 430071, Hubei, China.
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12
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Chen L, Hassani Nia F, Stauber T. Ion Channels and Transporters in Muscle Cell Differentiation. Int J Mol Sci 2021; 22:13615. [PMID: 34948411 PMCID: PMC8703453 DOI: 10.3390/ijms222413615] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Revised: 12/04/2021] [Accepted: 12/14/2021] [Indexed: 01/12/2023] Open
Abstract
Investigations on ion channels in muscle tissues have mainly focused on physiological muscle function and related disorders, but emerging evidence supports a critical role of ion channels and transporters in developmental processes, such as controlling the myogenic commitment of stem cells. In this review, we provide an overview of ion channels and transporters that influence skeletal muscle myoblast differentiation, cardiac differentiation from pluripotent stem cells, as well as vascular smooth muscle cell differentiation. We highlight examples of model organisms or patients with mutations in ion channels. Furthermore, a potential underlying molecular mechanism involving hyperpolarization of the resting membrane potential and a series of calcium signaling is discussed.
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Affiliation(s)
- Lingye Chen
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany;
- Zhongshan School of Medicine, Sun Yat-Sen University, Guangzhou 510080, China
| | - Fatemeh Hassani Nia
- Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany;
| | - Tobias Stauber
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, 14195 Berlin, Germany;
- Institute for Molecular Medicine, MSH Medical School Hamburg, 20457 Hamburg, Germany;
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13
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Kolobkova Y, Pervaiz S, Stauber T. The expanding toolbox to study the LRRC8-formed volume-regulated anion channel VRAC. CURRENT TOPICS IN MEMBRANES 2021; 88:119-163. [PMID: 34862024 DOI: 10.1016/bs.ctm.2021.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The volume-regulated anion channel (VRAC) is activated upon cell swelling and facilitates the passive movement of anions across the plasma membrane in cells. VRAC function underlies many critical homeostatic processes in vertebrate cells. Among them are the regulation of cell volume and membrane potential, glutamate release and apoptosis. VRAC is also permeable for organic osmolytes and metabolites including some anti-cancer drugs and antibiotics. Therefore, a fundamental understanding of VRAC's structure-function relationships, its physiological roles, its utility for therapy of diseases, and the development of compounds modulating its activity are important research frontiers. Here, we describe approaches that have been applied to study VRAC since it was first described more than 30 years ago, providing an overview of the recent methodological progress. The diverse applications reflecting a compromise between the physiological situation, biochemical definition, and biophysical resolution range from the study of VRAC activity using a classic electrophysiology approach, to the measurement of osmolytes transport by various means and the investigation of its activation using a novel biophysical approach based on fluorescence resonance energy transfer.
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Affiliation(s)
- Yulia Kolobkova
- Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Germany
| | - Sumaira Pervaiz
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany
| | - Tobias Stauber
- Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Germany; Institute of Chemistry and Biochemistry, Freie Universität Berlin, Germany.
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Deneka D, Rutz S, Hutter CAJ, Seeger MA, Sawicka M, Dutzler R. Allosteric modulation of LRRC8 channels by targeting their cytoplasmic domains. Nat Commun 2021; 12:5435. [PMID: 34521847 PMCID: PMC8440666 DOI: 10.1038/s41467-021-25742-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Accepted: 08/26/2021] [Indexed: 11/09/2022] Open
Abstract
Members of the LRRC8 family form heteromeric assemblies, which function as volume-regulated anion channels. These modular proteins consist of a transmembrane pore and cytoplasmic leucine-rich repeat (LRR) domains. Despite their known molecular architecture, the mechanism of activation and the role of the LRR domains in this process has remained elusive. Here we address this question by generating synthetic nanobodies, termed sybodies, which target the LRR domain of the obligatory subunit LRRC8A. We use these binders to investigate their interaction with homomeric LRRC8A channels by cryo-electron microscopy and the consequent effect on channel activation by electrophysiology. The five identified sybodies either inhibit or enhance activity by binding to distinct epitopes of the LRR domain, thereby altering channel conformations. In combination, our work provides a set of specific modulators of LRRC8 proteins and reveals the role of their cytoplasmic domains as regulators of channel activity by allosteric mechanisms.
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Affiliation(s)
- Dawid Deneka
- Department of Biochemistry University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Sonja Rutz
- Department of Biochemistry University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland
| | - Cedric A J Hutter
- Institute of Medical Microbiology University of Zurich, Gloriastrasse 28/30, CH-8006, Zurich, Switzerland
| | - Markus A Seeger
- Institute of Medical Microbiology University of Zurich, Gloriastrasse 28/30, CH-8006, Zurich, Switzerland
| | - Marta Sawicka
- Department of Biochemistry University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
| | - Raimund Dutzler
- Department of Biochemistry University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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Chen L, König B, Stauber T. LRRC8 channel activation and reduction in cytosolic chloride concentration during early differentiation of C2C12 myoblasts. Biochem Biophys Res Commun 2020; 532:482-488. [PMID: 32892951 DOI: 10.1016/j.bbrc.2020.08.080] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 08/23/2020] [Indexed: 01/09/2023]
Abstract
Leucine-rich repeat containing family 8 (LRRC8) proteins form the volume-regulated anion channel (VRAC). Recently, they were shown to be required for normal differentiation and fusion of C2C12 myoblasts, by promoting membrane hyperpolarization and intracellular Ca2+ signals. However, the mechanism by which they are involved remained obscure. Here, using a FRET-based sensor for VRAC activity, we show temporary activation of VRAC within the first 2 h of myogenic differentiation. During this period, we also observed a significant decrease in the intracellular Cl- concentration that was abolished by the VRAC inhibitor carbenoxolone. However, lowering the intracellular Cl- concentration by extracellular Cl- depletion did not promote differentiation as judged by the percentage of myogenin-positive nuclei or total myogenin levels in C2C12 cells. Instead, it inhibited myosin expression and myotube formation. Together, these data suggest that VRAC is activated and mediates Cl- efflux early on during myogenic differentiation, and a moderate intracellular Cl- concentration is necessary for myoblast fusion.
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Affiliation(s)
- Lingye Chen
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany
| | - Benjamin König
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany
| | - Tobias Stauber
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195, Berlin, Germany; Department of Human Medicine and Institute for Molecular Medicine, MSH Medical School Hamburg, Am Kaiserkai 1, 20457, Hamburg, Germany.
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LRRC8A:C/E Heteromeric Channels Are Ubiquitous Transporters of cGAMP. Mol Cell 2020; 80:578-591.e5. [PMID: 33171122 DOI: 10.1016/j.molcel.2020.10.021] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 08/20/2020] [Accepted: 10/13/2020] [Indexed: 02/07/2023]
Abstract
Extracellular 2'3'-cyclic-GMP-AMP (cGAMP) is an immunotransmitter exported by diseased cells and imported into host cells to activate the innate immune STING pathway. We previously identified SLC19A1 as a cGAMP importer, but its use across human cell lines is limited. Here, we identify LRRC8A heteromeric channels, better known as volume-regulated anion channels (VRAC), as widely expressed cGAMP transporters. LRRC8A forms complexes with LRRC8C and/or LRRC8E, depending on their expression levels, to transport cGAMP and other 2'3'-cyclic dinucleotides. In contrast, LRRC8D inhibits cGAMP transport. We demonstrate that cGAMP is effluxed or influxed via LRRC8 channels, as dictated by the cGAMP electrochemical gradient. Activation of LRRC8A channels, which can occur under diverse stresses, strongly potentiates cGAMP transport. We identify activator sphingosine 1-phosphate and inhibitor DCPIB as chemical tools to manipulate channel-mediated cGAMP transport. Finally, LRRC8A channels are key cGAMP transporters in resting primary human vasculature cells and universal human cGAMP transporters when activated.
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