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Lei M, Salvage SC, Jackson AP, Huang CLH. Cardiac arrhythmogenesis: roles of ion channels and their functional modification. Front Physiol 2024; 15:1342761. [PMID: 38505707 PMCID: PMC10949183 DOI: 10.3389/fphys.2024.1342761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 01/22/2024] [Indexed: 03/21/2024] Open
Abstract
Cardiac arrhythmias cause significant morbidity and mortality and pose a major public health problem. They arise from disruptions in the normally orderly propagation of cardiac electrophysiological activation and recovery through successive cardiomyocytes in the heart. They reflect abnormalities in automaticity, initiation, conduction, or recovery in cardiomyocyte excitation. The latter properties are dependent on surface membrane electrophysiological mechanisms underlying the cardiac action potential. Their disruption results from spatial or temporal instabilities and heterogeneities in the generation and propagation of cellular excitation. These arise from abnormal function in their underlying surface membrane, ion channels, and transporters, as well as the interactions between them. The latter, in turn, form common regulatory targets for the hierarchical network of diverse signaling mechanisms reviewed here. In addition to direct molecular-level pharmacological or physiological actions on these surface membrane biomolecules, accessory, adhesion, signal transduction, and cytoskeletal anchoring proteins modify both their properties and localization. At the cellular level of excitation-contraction coupling processes, Ca2+ homeostatic and phosphorylation processes affect channel activity and membrane excitability directly or through intermediate signaling. Systems-level autonomic cellular signaling exerts both acute channel and longer-term actions on channel expression. Further upstream intermediaries from metabolic changes modulate the channels both themselves and through modifying Ca2+ homeostasis. Finally, longer-term organ-level inflammatory and structural changes, such as fibrotic and hypertrophic remodeling, similarly can influence all these physiological processes with potential pro-arrhythmic consequences. These normal physiological processes may target either individual or groups of ionic channel species and alter with particular pathological conditions. They are also potentially alterable by direct pharmacological action, or effects on longer-term targets modifying protein or cofactor structure, expression, or localization. Their participating specific biomolecules, often clarified in experimental genetically modified models, thus constitute potential therapeutic targets. The insights clarified by the physiological and pharmacological framework outlined here provide a basis for a recent modernized drug classification. Together, they offer a translational framework for current drug understanding. This would facilitate future mechanistically directed therapeutic advances, for which a number of examples are considered here. The latter are potentially useful for treating cardiac, in particular arrhythmic, disease.
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Affiliation(s)
- Ming Lei
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Samantha C. Salvage
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Antony P. Jackson
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Christopher L.-H. Huang
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
- Physiological Laboratory, University of Cambridge, Cambridge, United Kingdom
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2
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Thiel G, Rössler OG. Calmodulin Regulates Transient Receptor Potential TRPM3 and TRPM8-Induced Gene Transcription. Int J Mol Sci 2023; 24:ijms24097902. [PMID: 37175607 PMCID: PMC10178570 DOI: 10.3390/ijms24097902] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Revised: 04/23/2023] [Accepted: 04/24/2023] [Indexed: 05/15/2023] Open
Abstract
Calmodulin is a small protein that binds Ca2+ ions via four EF-hand motifs. The Ca2+/calmodulin complex as well as Ca2+-free calmodulin regulate the activities of numerous enzymes and ion channels. Here, we used genetic and pharmacological tools to study the functional role of calmodulin in regulating signal transduction of TRPM3 and TRPM8 channels. Both TRPM3 and TRPM8 are important regulators of thermosensation. Gene transcription triggered by stimulation of TRPM3 or TRPM8 channels was significantly impaired in cells expressing a calmodulin mutant with mutations in all four EF-hand Ca2+ binding motifs. Similarly, incubation of cells with the calmodulin inhibitor ophiobolin A reduced TRPM3 and TRPM8-induced signaling. The Ca2+/calmodulin-dependent protein phosphatase calcineurin was shown to negatively regulate TRPM3-induced gene transcription. Here, we show that TRPM8-induced transcription is also regulated by calcineurin. We propose that calmodulin plays a dual role in regulating TRPM3 and TRPM8 functions. Calmodulin is required for the activation of TRPM3 and TRPM8-induced intracellular signaling, most likely through a direct interaction with the channels. Ca2+ influx through TRPM3 and TRPM8 feeds back to TRPM3 and TRPM8-induced signaling by activation of the calmodulin-regulated enzyme calcineurin, which acts as a negative feedback loop for both TRPM3 and TRPM8 channel signaling.
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Affiliation(s)
- Gerald Thiel
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
| | - Oliver G Rössler
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Building 44, 66421 Homburg, Germany
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3
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Wray S, Prendergast C, Arrowsmith S. Calcium-Activated Chloride Channels in Myometrial and Vascular Smooth Muscle. Front Physiol 2021; 12:751008. [PMID: 34867456 PMCID: PMC8637852 DOI: 10.3389/fphys.2021.751008] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 09/24/2021] [Indexed: 11/24/2022] Open
Abstract
In smooth muscle tissues, calcium-activated chloride channels (CaCC) provide the major anionic channel. Opening of these channels leads to chloride efflux and depolarization of the myocyte membrane. In this way, activation of the channels by a rise of intracellular [Ca2+], from a variety of sources, produces increased excitability and can initiate action potentials and contraction or increased tone. We now have a good mechanistic understanding of how the channels are activated and regulated, due to identification of TMEM16A (ANO1) as the molecular entity of the channel, but key questions remain. In reviewing these channels and comparing two distinct smooth muscles, myometrial and vascular, we expose the differences that occur in their activation mechanisms, properties, and control. We find that the myometrium only expresses “classical,” Ca2+-activated, and voltage sensitive channels, whereas both tonic and phasic blood vessels express classical, and non-classical, cGMP-regulated CaCC, which are voltage insensitive. This translates to more complex activation and regulation in vascular smooth muscles, irrespective of whether they are tonic or phasic. We therefore tentatively conclude that although these channels are expressed and functionally important in all smooth muscles, they are probably not part of the mechanisms governing phasic activity. Recent knockdown studies have produced unexpected functional results, e.g. no effects on labour and delivery, and tone increasing in some but decreasing in other vascular beds, strongly suggesting that there is still much to be explored concerning CaCC in smooth muscle.
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Affiliation(s)
- Susan Wray
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Clodagh Prendergast
- Department of Women and Children's Health, Institute of Life Course and Medical Sciences, University of Liverpool, Liverpool, United Kingdom
| | - Sarah Arrowsmith
- Department of Life Sciences, Manchester Metropolitan University, Manchester, United Kingdom
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4
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Hawn MB, Akin E, Hartzell H, Greenwood IA, Leblanc N. Molecular mechanisms of activation and regulation of ANO1-Encoded Ca 2+-Activated Cl - channels. Channels (Austin) 2021; 15:569-603. [PMID: 34488544 PMCID: PMC8480199 DOI: 10.1080/19336950.2021.1975411] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 08/29/2021] [Indexed: 01/13/2023] Open
Abstract
Ca2+-activated Cl- channels (CaCCs) perform a multitude of functions including the control of cell excitability, regulation of cell volume and ionic homeostasis, exocrine and endocrine secretion, fertilization, amplification of olfactory sensory function, and control of smooth muscle cell contractility. CaCCs are the translated products of two members (ANO1 and ANO2, also known as TMEM16A and TMEM16B) of the Anoctamin family of genes comprising ten paralogs. This review focuses on recent progress in understanding the molecular mechanisms involved in the regulation of ANO1 by cytoplasmic Ca2+, post-translational modifications, and how the channel protein interacts with membrane lipids and protein partners. After first reviewing the basic properties of native CaCCs, we then present a brief historical perspective highlighting controversies about their molecular identity in native cells. This is followed by a summary of the fundamental biophysical and structural properties of ANO1. We specifically address whether the channel is directly activated by internal Ca2+ or indirectly through the intervention of the Ca2+-binding protein Calmodulin (CaM), and the structural domains responsible for Ca2+- and voltage-dependent gating. We then review the regulation of ANO1 by internal ATP, Calmodulin-dependent protein kinase II-(CaMKII)-mediated phosphorylation and phosphatase activity, membrane lipids such as the phospholipid phosphatidyl-(4,5)-bisphosphate (PIP2), free fatty acids and cholesterol, and the cytoskeleton. The article ends with a survey of physical and functional interactions of ANO1 with other membrane proteins such as CLCA1/2, inositol trisphosphate and ryanodine receptors in the endoplasmic reticulum, several members of the TRP channel family, and the ancillary Κ+ channel β subunits KCNE1/5.
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Affiliation(s)
- M. B. Hawn
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - E. Akin
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
| | - H.C. Hartzell
- Department of Cell Biology, Emory University School of Medicine, USA
| | - I. A. Greenwood
- Department of Vascular Pharmacology, St. George’s University of London, UK
| | - N. Leblanc
- Department of Pharmacology and Center of Biomedical Research Excellence for Molecular and Cellular Signal Transduction in the Cardiovascular System, University of Nevada, Reno School of Medicine, Reno, United States
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5
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Calmodulin-Dependent Regulation of Overexpressed but Not Endogenous TMEM16A Expressed in Airway Epithelial Cells. MEMBRANES 2021; 11:membranes11090723. [PMID: 34564540 PMCID: PMC8471323 DOI: 10.3390/membranes11090723] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/16/2021] [Accepted: 09/20/2021] [Indexed: 11/30/2022]
Abstract
Regulation of the Ca2+-activated Cl− channel TMEM16A by Ca2+/calmodulin (CAM) is discussed controversially. In the present study, we compared regulation of TMEM16A by Ca2+/calmodulin (holo-CAM), CAM-dependent kinase (CAMKII), and CAM-dependent phosphatase calcineurin in TMEM16A-overexpressing HEK293 cells and TMEM16A expressed endogenously in airway and colonic epithelial cells. The activator of the Ca2+/CAM-regulated K+ channel KCNN4, 1-EBIO, activated TMEM16A in overexpressing cells, but not in cells with endogenous expression of TMEM16A. Evidence is provided that CAM-interaction with TMEM16A modulates the Ca2+ sensitivity of the Cl− channel. Enhanced Ca2+ sensitivity of overexpressed TMEM16A explains its activity at basal (non-elevated) intracellular Ca2+ levels. The present results correspond well to a recent report that demonstrates a Ca2+-unbound form of CAM (apo-CAM) that is pre-associated with TMEM16A and mediates a Ca2+-dependent sensitization of activation (and inactivation). However, when using activators or inhibitors for holo-CAM, CAMKII, or calcineurin, we were unable to detect a significant impact of CAM, and limit evidence for regulation by CAM-dependent regulatory proteins on receptor-mediated activation of endogenous TMEM16A in airway or colonic epithelial cells. We propose that regulatory properties of TMEM16A and and other members of the TMEM16 family as detected in overexpression studies, should be validated for endogenous TMEM16A and physiological stimuli such as activation of phospholipase C (PLC)-coupled receptors.
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6
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Anion and Cation Permeability of the Mouse TMEM16F Calcium-Activated Channel. Int J Mol Sci 2021; 22:ijms22168578. [PMID: 34445284 PMCID: PMC8395294 DOI: 10.3390/ijms22168578] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 07/31/2021] [Accepted: 08/04/2021] [Indexed: 12/27/2022] Open
Abstract
TMEM16F is involved in several physiological processes, such as blood coagulation, bone development and virus infections. This protein acts both as a Ca2+-dependent phospholipid scramblase and a Ca2+-activated ion channel but several studies have reported conflicting results about the ion selectivity of the TMEM16F-mediated current. Here, we have performed a detailed side-by-side comparison of the ion selectivity of TMEM16F using the whole-cell and inside-out excised patch configurations to directly compare the results. In inside-out configuration, Ca2+-dependent activation was fast and the TMEM16F-mediated current was activated in a few milliseconds, while in whole-cell recordings full activation required several minutes. We determined the relative permeability between Na+ and Cl¯ (PNa/PCl) using the dilution method in both configurations. The TMEM16F-mediated current was highly nonselective, but there were differences depending on the configuration of the recordings. In whole-cell recordings, PNa/PCl was approximately 0.5, indicating a slight preference for Cl¯ permeation. In contrast, in inside-out experiments the TMEM16F channel showed a higher permeability for Na+ with PNa/PCl reaching 3.7. Our results demonstrate that the time dependence of Ca2+ activation and the ion selectivity of TMEM16F depend on the recording configuration.
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7
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The Groovy TMEM16 Family: Molecular Mechanisms of Lipid Scrambling and Ion Conduction. J Mol Biol 2021; 433:166941. [PMID: 33741412 DOI: 10.1016/j.jmb.2021.166941] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 03/09/2021] [Accepted: 03/09/2021] [Indexed: 12/28/2022]
Abstract
The TMEM16 family of membrane proteins displays a remarkable functional dichotomy - while some family members function as Ca2+-activated anion channels, the majority of characterized TMEM16 homologs are Ca2+-activated lipid scramblases, which catalyze the exchange of phospholipids between the two membrane leaflets. Furthermore, some TMEM16 scramblases can also function as channels. Due to their involvement in important physiological processes, the family has been actively studied ever since their molecular identity was unraveled. In this review, we will summarize the recent advances in the field and how they influenced our view of TMEM16 family function and evolution. Structural, functional and computational studies reveal how relatively small rearrangements in the permeation pathway are responsible for the observed functional duality: while TMEM16 scramblases can adopt both ion- and lipid conductive conformations, TMEM16 channels can only populate the former. Recent data further provides the molecular details of a stepwise activation mechanism, which is initiated by Ca2+ binding and modulated by various cellular factors, including lipids. TMEM16 function and the surrounding membrane properties are inextricably intertwined, with the protein inducing bilayer deformations associated with scrambling, while the surrounding lipids modulate TMEM16 conformation and activity.
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8
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Roh JW, Hwang GE, Kim WK, Nam JH. Ca 2+ Sensitivity of Anoctamin 6/TMEM16F Is Regulated by the Putative Ca 2+-Binding Reservoir at the N-Terminal Domain. Mol Cells 2021; 44:88-100. [PMID: 33658434 PMCID: PMC7941003 DOI: 10.14348/molcells.2021.2203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 01/05/2021] [Accepted: 01/26/2021] [Indexed: 11/27/2022] Open
Abstract
Anoctamin 6/TMEM16F (ANO6) is a dual-function protein with Ca2+-activated ion channel and Ca2+-activated phospholipid scramblase activities, requiring a high intracellular Ca2+ concentration (e.g., half-maximal effective Ca2+ concentration [EC50] of [Ca2+]i > 10 μM), and strong and sustained depolarization above 0 mV. Structural comparison with Anoctamin 1/TMEM16A (ANO1), a canonical Ca2+- activated chloride channel exhibiting higher Ca2+ sensitivity (EC50 of 1 μM) than ANO6, suggested that a homologous Ca2+-transferring site in the N-terminal domain (Nt) might be responsible for the differential Ca2+ sensitivity and kinetics of activation between ANO6 and ANO1. To elucidate the role of the putative Ca2+-transferring reservoir in the Nt (Nt-CaRes), we constructed an ANO6-1-6 chimera in which Nt-CaRes was replaced with the corresponding domain of ANO1. ANO6- 1-6 showed higher sensitivity to Ca2+ than ANO6. However, neither the speed of activation nor the voltage-dependence differed between ANO6 and ANO6-1-6. Molecular dynamics simulation revealed a reduced Ca2+ interaction with Nt- CaRes in ANO6 than ANO6-1-6. Moreover, mutations on potentially Ca2+-interacting acidic amino acids in ANO6 Nt- CaRes resulted in reduced Ca2+ sensitivity, implying direct interactions of Ca2+ with these residues. Based on these results, we cautiously suggest that the net charge of Nt- CaRes is responsible for the difference in Ca2+ sensitivity between ANO1 and ANO6.
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Affiliation(s)
- Jae Won Roh
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea
| | - Ga Eun Hwang
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea
| | - Woo Kyung Kim
- Department of Internal Medicine, Graduate School of Medicine, Dongguk University, Goyang 10326, Korea
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Korea
| | - Joo Hyun Nam
- Department of Physiology, Dongguk University College of Medicine, Gyeongju 38066, Korea
- Channelopathy Research Center (CRC), Dongguk University College of Medicine, Goyang 10326, Korea
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9
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Boccaccio A, Menini A, Pifferi S. The cyclic AMP signaling pathway in the rodent main olfactory system. Cell Tissue Res 2021; 383:429-443. [PMID: 33447881 DOI: 10.1007/s00441-020-03391-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 12/10/2020] [Indexed: 01/15/2023]
Abstract
Odor perception begins with the detection of odorant molecules by the main olfactory epithelium located in the nasal cavity. Odorant molecules bind to and activate a large family of G-protein-coupled odorant receptors and trigger a cAMP-mediated transduction cascade that converts the chemical stimulus into an electrical signal transmitted to the brain. Morever, odorant receptors and cAMP signaling plays a relevant role in olfactory sensory neuron development and axonal targeting to the olfactory bulb. This review will first explore the physiological response of olfactory sensory neurons to odorants and then analyze the different components of cAMP signaling and their different roles in odorant detection and olfactory sensory neuron development.
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Affiliation(s)
- Anna Boccaccio
- Institute of Biophysics, National Research Council (CNR), Genova, Italy.
| | - Anna Menini
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy
| | - Simone Pifferi
- Neurobiology Group, SISSA, Scuola Internazionale Superiore di Studi Avanzati, Trieste, Italy.,Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, Ancona, Italy
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10
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Wang KY, Huang RY, Tong XZ, Zhang KN, Liu YW, Zeng F, Hu HM, Jiang T. Molecular and clinical characterization of TMEM71 expression at the transcriptional level in glioma. CNS Neurosci Ther 2019; 25:965-975. [PMID: 31180187 PMCID: PMC6698980 DOI: 10.1111/cns.13137] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Revised: 03/20/2019] [Accepted: 03/25/2019] [Indexed: 12/23/2022] Open
Abstract
Background Glioma is the most common and aggressive type of primary brain tumor in adults. Although radiotherapy and chemotherapy are used in the treatment of glioma, survival remains unsatisfactory. Chemoresistance is one of the primary reasons for the poor prognosis of glioma. Several studies have demonstrated that glioma stem cells (GSC) may be one of the reasons for chemoresistance. In this article, we attempt to search for a new biomarker related to GSC and chemoresistance in glioma. Methods We used three datasets (GSE23806, COSMIC, and CGGA) to search for the genes related to GSC, temozolomide (TMZ) resistance, and overall survival. The selected gene was investigated with respect to the relationship between mRNA levels and clinical characteristics in the CGGA and TCGA dataset. Gene ontology (GO) analysis was used for bioinformatics analysis. Kaplan‐Meier survival analysis and Cox regression analysis were used for survival analysis. Results The transmembrane protein 71 (TMEM71) gene was selected for further research. TMEM71 was highly expressed in GSCs and TMZ‐resistant cells. The TMEM71 mRNA levels increased with increasing grades of glioma. In IDH‐wild‐type and MGMT‐unmethylated samples, TMEM71 was overexpressed. The TMEM71 transcript levels were also increased significantly in mesenchymal subtype gliomas. GO analysis demonstrated that TMEM71 was related to the immune and inflammatory responses, cell proliferation, cell migration, chemotaxis, and the response to drugs. Specifically, PD‐1, PD‐L1, TIM‐3, and B7‐H3 were tightly associated with TMEM71 expression. This result indicates that TMEM71 may play an important role in the immune response. More importantly, high expression of TMEM71 was correlated with short survival time in both glioma and glioblastoma patients. Conclusion In summary, TMEM71 expression was increased in GBM and associated with immune response. Our study suggests that TMEM71 may function as an oncogene and serve as a new effective therapeutic target for the treatment of glioma.
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Affiliation(s)
- Kuan-Yu Wang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Ruo-Yu Huang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Xue-Zhi Tong
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Ke-Nan Zhang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China
| | - Yan-Wei Liu
- Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Radiotherapy, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Fan Zeng
- Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Hui-Min Hu
- Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Neuropathology, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China
| | - Tao Jiang
- Department of Neurosurgery, Beijing Neurosurgical Institute, Capital Medical University, Beijing, China.,Chinese Glioma Cooperative Group (CGCG), Beijing, China.,Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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11
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Villalobo A, González-Muñoz M, Berchtold MW. Proteins with calmodulin-like domains: structures and functional roles. Cell Mol Life Sci 2019; 76:2299-2328. [PMID: 30877334 PMCID: PMC11105222 DOI: 10.1007/s00018-019-03062-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Revised: 02/26/2019] [Accepted: 03/07/2019] [Indexed: 12/21/2022]
Abstract
The appearance of modular proteins is a widespread phenomenon during the evolution of proteins. The combinatorial arrangement of different functional and/or structural domains within a single polypeptide chain yields a wide variety of activities and regulatory properties to the modular proteins. In this review, we will discuss proteins, that in addition to their catalytic, transport, structure, localization or adaptor functions, also have segments resembling the helix-loop-helix EF-hand motifs found in Ca2+-binding proteins, such as calmodulin (CaM). These segments are denoted CaM-like domains (CaM-LDs) and play a regulatory role, making these CaM-like proteins sensitive to Ca2+ transients within the cell, and hence are able to transduce the Ca2+ signal leading to specific cellular responses. Importantly, this arrangement allows to this group of proteins direct regulation independent of other Ca2+-sensitive sensor/transducer proteins, such as CaM. In addition, this review also covers CaM-binding proteins, in which their CaM-binding site (CBS), in the absence of CaM, is proposed to interact with other segments of the same protein denoted CaM-like binding site (CLBS). CLBS are important regulatory motifs, acting either by keeping these CaM-binding proteins inactive in the absence of CaM, enhancing the stability of protein complexes and/or facilitating their dimerization via CBS/CLBS interaction. The existence of proteins containing CaM-LDs or CLBSs substantially adds to the enormous versatility and complexity of Ca2+/CaM signaling.
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Affiliation(s)
- Antonio Villalobo
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, 28029, Madrid, Spain.
- Instituto de Investigaciones Sanitarias, Hospital Universitario La Paz, Edificio IdiPAZ, Paseo de la Castellana 261, 28046, Madrid, Spain.
| | - María González-Muñoz
- Department of Cancer Biology, Instituto de Investigaciones Biomédicas, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Arturo Duperier 4, 28029, Madrid, Spain
| | - Martin W Berchtold
- Department of Biology, University of Copenhagen, 13 Universitetsparken, 2100, Copenhagen, Denmark.
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12
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Falzone ME, Malvezzi M, Lee BC, Accardi A. Known structures and unknown mechanisms of TMEM16 scramblases and channels. J Gen Physiol 2018; 150:933-947. [PMID: 29915161 PMCID: PMC6028493 DOI: 10.1085/jgp.201711957] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 05/29/2018] [Indexed: 12/25/2022] Open
Abstract
Falzone et al. interpret the mechanisms underlying the activity of TMEM16 family members from recent structural and functional work. The TMEM16 family of membrane proteins is composed of both Ca2+-gated Cl− channels and Ca2+-dependent phospholipid scramblases. The functional diversity of TMEM16s underlies their involvement in numerous signal transduction pathways that connect changes in cytosolic Ca2+ levels to cellular signaling networks. Indeed, defects in the function of several TMEM16s cause a variety of genetic disorders, highlighting their fundamental pathophysiological importance. Here, we review how our mechanistic understanding of TMEM16 function has been shaped by recent functional and structural work. Remarkably, the recent determination of near-atomic-resolution structures of TMEM16 proteins of both functional persuasions has revealed how relatively minimal rearrangements in the substrate translocation pathway are sufficient to precipitate the dramatic functional differences that characterize the family. These structures, when interpreted in the light of extensive functional analysis, point to an unusual mechanism for Ca2+-dependent activation of TMEM16 proteins in which substrate permeation is regulated by a combination of conformational rearrangements and electrostatics. These breakthroughs pave the way to elucidate the mechanistic bases of ion and lipid transport by the TMEM16 proteins and unravel the molecular links between these transport activities and their function in human pathophysiology.
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Affiliation(s)
- Maria E Falzone
- Department of Biochemistry, Weill Cornell Medical School, New York, NY
| | - Mattia Malvezzi
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Byoung-Cheol Lee
- Department of Anesthesiology, Weill Cornell Medical School, New York, NY
| | - Alessio Accardi
- Department of Biochemistry, Weill Cornell Medical School, New York, NY .,Department of Anesthesiology, Weill Cornell Medical School, New York, NY.,Department of Physiology, Biophysics and Systems Biology, Weill Cornell Medical School, New York, NY
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13
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Kamaleddin MA. Molecular, biophysical, and pharmacological properties of calcium-activated chloride channels. J Cell Physiol 2017; 233:787-798. [PMID: 28121009 DOI: 10.1002/jcp.25823] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 01/24/2017] [Indexed: 12/15/2022]
Abstract
Calcium-activated chloride channels (CaCCs) are a family of anionic transmembrane ion channels. They are mainly responsible for the movement of Cl- and other anions across the biological membranes, and they are widely expressed in different tissues. Since the Cl- flow into or out of the cell plays a crucial role in hyperpolarizing or depolarizing the cells, respectively, the impact of intracellular Ca2+ concentration on these channels is attracting a lot of attentions. After summarizing the molecular, biophysical, and pharmacological properties of CaCCs, the role of CaCCs in normal cellular functions will be discussed, and I will emphasize how dysregulation of CaCCs in pathological conditions can account for different diseases. A better understanding of CaCCs and a pivotal regulatory role of Ca2+ can shed more light on the therapeutic strategies for different neurological disorders that arise from chloride dysregulation, such as asthma, cystic fibrosis, and neuropathic pain.
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Affiliation(s)
- Mohammad Amin Kamaleddin
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada.,Neurosciences and Mental Health, The Hospital for Sick Children, Toronto, Ontario, Canada
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Horváth B, Váczi K, Hegyi B, Gönczi M, Dienes B, Kistamás K, Bányász T, Magyar J, Baczkó I, Varró A, Seprényi G, Csernoch L, Nánási PP, Szentandrássy N. Sarcolemmal Ca(2+)-entry through L-type Ca(2+) channels controls the profile of Ca(2+)-activated Cl(-) current in canine ventricular myocytes. J Mol Cell Cardiol 2016; 97:125-39. [PMID: 27189885 DOI: 10.1016/j.yjmcc.2016.05.006] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 04/20/2016] [Accepted: 05/10/2016] [Indexed: 12/15/2022]
Abstract
Ca(2+)-activated Cl(-) current (ICl(Ca)) mediated by TMEM16A and/or Bestrophin-3 may contribute to cardiac arrhythmias. The true profile of ICl(Ca) during an actual ventricular action potential (AP), however, is poorly understood. We aimed to study the profile of ICl(Ca) systematically under physiological conditions (normal Ca(2+) cycling and AP voltage-clamp) as well as in conditions designed to change [Ca(2+)]i. The expression of TMEM16A and/or Bestrophin-3 in canine and human left ventricular myocytes was examined. The possible spatial distribution of these proteins and their co-localization with Cav1.2 was also studied. The profile of ICl(Ca), identified as a 9-anthracene carboxylic acid-sensitive current under AP voltage-clamp conditions, contained an early fast outward and a late inward component, overlapping early and terminal repolarizations, respectively. Both components were moderately reduced by ryanodine, while fully abolished by BAPTA, but not EGTA. [Ca(2+)]i was monitored using Fura-2-AM. Setting [Ca(2+)]i to the systolic level measured in the bulk cytoplasm (1.1μM) decreased ICl(Ca), while application of Bay K8644, isoproterenol, and faster stimulation rates increased the amplitude of ICl(Ca). Ca(2+)-entry through L-type Ca(2+) channels was essential for activation of ICl(Ca). TMEM16A and Bestrophin-3 showed strong co-localization with one another and also with Cav1.2 channels, when assessed using immunolabeling and confocal microscopy in both canine myocytes and human ventricular myocardium. Activation of ICl(Ca) in canine ventricular cells requires Ca(2+)-entry through neighboring L-type Ca(2+) channels and is only augmented by SR Ca(2+)-release. Substantial activation of ICl(Ca) requires high Ca(2+) concentration in the dyadic clefts which can be effectively buffered by BAPTA, but not EGTA.
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Affiliation(s)
- Balázs Horváth
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary; Faculty of Pharmacy, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Krisztina Váczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Bence Hegyi
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Mónika Gönczi
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary; MTA-DE Momentum, Laboratory of Protein Dynamics, Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Beatrix Dienes
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Kornél Kistamás
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Tamás Bányász
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - János Magyar
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary; Division of Sport Physiology, Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - István Baczkó
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Dóm tér 12, P.O. Box 427, Hungary
| | - András Varró
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, University of Szeged, H-6720 Szeged, Dóm tér 12, P.O. Box 427, Hungary; MTA-SZTE Research Group of Cardiovascular Pharmacology, Hungarian Academy of Sciences, H-6720 Szeged, Dóm tér 12, P.O. Box 427, Hungary
| | - György Seprényi
- Department of Medical Biology, Faculty of Medicine, University of Szeged, H-6720 Szeged, Somogyi Béla utca 4, P.O. Box 427, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Péter P Nánási
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary; Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary
| | - Norbert Szentandrássy
- Department of Physiology, Faculty of Medicine, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary; Department of Dental Physiology and Pharmacology, Faculty of Dentistry, University of Debrecen, H-4012 Debrecen, Nagyerdei krt 98, P.O. Box 22, Hungary.
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