1
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Zhang M, Tang S, Wang X, Fang S, Li Y. Mechanosensitive channel MscL gating transitions coupling with constriction point shift. Protein Sci 2024; 33:e4965. [PMID: 38501596 PMCID: PMC10949393 DOI: 10.1002/pro.4965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/23/2024] [Accepted: 03/04/2024] [Indexed: 03/20/2024]
Abstract
The mechanosensitive channel of large conductance (MscL) acts as an "emergency release valve" that protects bacterial cells from acute hypoosmotic stress, and it serves as a paradigm for studying the mechanism underlying the transduction of mechanical forces. MscL gating is proposed to initiate with an expansion without opening, followed by subsequent pore opening via a number of intermediate substates, and ends in a full opening. However, the details of gating process are still largely unknown. Using in vivo viability assay, single channel patch clamp recording, cysteine cross-linking, and tryptophan fluorescence quenching approach, we identified and characterized MscL mutants with different occupancies of constriction region in the pore domain. The results demonstrated the shifts of constriction point along the gating pathway towards cytoplasic side from residue G26, though G22, to L19 upon gating, indicating the closed-expanded transitions coupling of the expansion of tightly packed hydrophobic constriction region to conduct the initial ion permeation in response to the membrane tension. Furthermore, these transitions were regulated by the hydrophobic and lipidic interaction with the constricting "hot spots". Our data reveal a new resolution of the transitions from the closed to the opening substate of MscL, providing insights into the gating mechanisms of MscL.
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Affiliation(s)
- Mingfeng Zhang
- Department of Cell Biology, College of MedicineJiaxing UniversityJiaxingChina
- School of Life ScienceWestlake UniversityHangzhouChina
- School of Brain Science and Brain MedicineZhejiang University School of MedicineHangzhouChina
| | - Siyang Tang
- School of Brain Science and Brain MedicineZhejiang University School of MedicineHangzhouChina
| | - Xiaomin Wang
- Department of Cell Biology, College of MedicineJiaxing UniversityJiaxingChina
| | - Sanhua Fang
- Core FacilitiesZhejiang University School of MedicineHangzhouChina
| | - Yuezhou Li
- Department of Cell Biology, College of MedicineJiaxing UniversityJiaxingChina
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2
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Liu X, Li X, Liao L. Abnormal urodynamic changes in post-upper urinary tract dysfunction in ureteral obstruction rat models. Front Physiol 2024; 15:1341220. [PMID: 38362490 PMCID: PMC10867635 DOI: 10.3389/fphys.2024.1341220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 01/15/2024] [Indexed: 02/17/2024] Open
Abstract
Objects: This study investigated changes in upper urinary tract urodynamics (UUTU) after upper urinary tract dysfunction (UUTD). Methods: The UUTD model was induced through unilateral ureteral obstruction. To measure the renal pelvis volume, and resting pressure. Ureteral electromyography (EMG) and in situ ureteral constriction experiments were performed. Ureteral tissue was obtained for HE and masson staining, IF staining and IHC research to explore the distribution of Piezo1, and the expression of Piezo1 was studied using Western blotting. Results: The study showed that the renal pelvis volumes and the renal pelvis resting pressures gradually increased post surgery in the experimental group. The degree of ureteral tissue edema, cell necrosis and fibrosis gradually increased. The maximum contraction force and frequency of ureter in the experimental group post surgery were significantly higher than in the sham group. Western blotting showed that the expression intensity of Piezo1 gradually increased and was significantly higher than in the sham group. Further analysis of each sub-layer of the ureter revealed that Piezo1 was highly expressed in the urothelium layer, followed by the suburothelium layer, and had low expression in the smooth muscle cell layer. Conclusion: The study observed that morphological and electrophysiological changes in the upper urinary tract may be important mechanisms of abnormal UUTU. Increased expression of the Piezo1 may be a new molecular mechanism of abnormal urodynamics after UUTD.
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Affiliation(s)
- Xin Liu
- Shandong University, Jinan, Shandong, China
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- University of Health and Rehabilitation Sciences, Qingdao, Shandong, China
- China Rehabilitation Science Institute, Beijing, China
- Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
| | - Xing Li
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- School of Rehabilitation, Capital Medical University, Beijing, China
| | - Limin Liao
- Shandong University, Jinan, Shandong, China
- Department of Urology, China Rehabilitation Research Center, Beijing Bo'ai Hospital, Beijing, China
- University of Health and Rehabilitation Sciences, Qingdao, Shandong, China
- China Rehabilitation Science Institute, Beijing, China
- Beijing Key Laboratory of Neural Injury and Rehabilitation, Beijing, China
- School of Rehabilitation, Capital Medical University, Beijing, China
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3
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Jiang W, Wijerathne TD, Zhang H, Lin YC, Jo S, Im W, Lacroix JJ, Luo YL. Structural and thermodynamic framework for PIEZO1 modulation by small molecules. Proc Natl Acad Sci U S A 2023; 120:e2310933120. [PMID: 38060566 PMCID: PMC10723123 DOI: 10.1073/pnas.2310933120] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/12/2023] [Indexed: 12/17/2023] Open
Abstract
Mechanosensitive PIEZO channels constitute potential pharmacological targets for multiple clinical conditions, spurring the search for potent chemical PIEZO modulators. Among them is Yoda1, a widely used synthetic small molecule PIEZO1 activator discovered through cell-based high-throughput screening. Yoda1 is thought to bind to PIEZO1's mechanosensory arm domain, sandwiched between two transmembrane regions near the channel pore. However, how the binding of Yoda1 to this region promotes channel activation remains elusive. Here, we first demonstrate that cross-linking PIEZO1 repeats A and B with disulfide bridges reduces the effects of Yoda1 in a redox-dependent manner, suggesting that Yoda1 acts by perturbing the contact between these repeats. Using molecular dynamics-based absolute binding free energy simulations, we next show that Yoda1 preferentially occupies a deeper, amphipathic binding site with higher affinity in PIEZO1 open state. Using Yoda1's binding poses in open and closed states, relative binding free energy simulations were conducted in the membrane environment, recapitulating structure-activity relationships of known Yoda1 analogs. Through virtual screening of an 8 million-compound library using computed fragment maps of the Yoda1 binding site, we subsequently identified two chemical scaffolds with agonist activity toward PIEZO1. This study supports a pharmacological model in which Yoda1 activates PIEZO1 by wedging repeats A and B, providing a structural and thermodynamic framework for the rational design of PIEZO1 modulators. Beyond PIEZO channels, the three orthogonal computational approaches employed here represent a promising path toward drug discovery in highly heterogeneous membrane protein systems.
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Affiliation(s)
- Wenjuan Jiang
- Department of Biotechnology and Pharmaceutical Sciences, Western University of Health Sciences, Pomona, CA91766
| | - Tharaka D. Wijerathne
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA91766
| | - Han Zhang
- Department of Biological Sciences, Lehigh University, Bethlehem, PA18015
- Department of Chemistry, Lehigh University, Bethlehem, PA18015
- Department of Bioengineering, Lehigh University, Bethlehem, PA18015
- Department of Computer Science and Engineering, Lehigh University, Bethlehem, PA18015
| | - Yi-Chun Lin
- Department of Biotechnology and Pharmaceutical Sciences, Western University of Health Sciences, Pomona, CA91766
| | - Sunhwan Jo
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, MD21201
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, PA18015
- Department of Chemistry, Lehigh University, Bethlehem, PA18015
- Department of Bioengineering, Lehigh University, Bethlehem, PA18015
- Department of Computer Science and Engineering, Lehigh University, Bethlehem, PA18015
| | - Jerome J. Lacroix
- Department of Basic Medical Sciences, Western University of Health Sciences, Pomona, CA91766
| | - Yun L. Luo
- Department of Biotechnology and Pharmaceutical Sciences, Western University of Health Sciences, Pomona, CA91766
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Sawada Y, Nomura T, Martinac B, Sokabe M. A novel force transduction pathway from a tension sensor to the gate in the mechano-gating of MscL channel. Front Chem 2023; 11:1175443. [PMID: 37347044 PMCID: PMC10279863 DOI: 10.3389/fchem.2023.1175443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 05/22/2023] [Indexed: 06/23/2023] Open
Abstract
The bacterial mechanosensitive channel of large conductance MscL is activated exclusively by increased tension in the membrane bilayer. Despite many proposed models for MscL opening, its precise mechano-gating mechanism, particularly how the received force at the tension sensor transmits to the gate remains incomplete. Previous studies have shown that along with amphipathic N-terminus located near the cytoplasmic surface of the membrane, Phe78 residue near the outer surface also acts as a "tension sensor," while Gly22 is a central constituent of the "hydrophobic gate." Present study focused on elucidating the force transmission mechanism from the sensor Phe78 in the outer transmembrane helix (TM2) to the gate in the inner transmembrane helix (TM1) of MscL by applying the patch clamp and molecular dynamics (MD) simulations to the wild type MscL channel and its single mutants at the sensor (F78N), the gate (G22N) and their combination (G22N/F78N) double mutant. F78N MscL resulted in a severe loss-of-function, while G22N MscL caused a gain-of-function channel exhibiting spontaneous openings at the resting membrane tension. We initially speculated that the spontaneous opening in G22N mutant might occur without tension acting on Phe78 residue. To test this hypothesis, we examined the (G22N/F78N) double mutant, which unexpectedly exhibited neither spontaneous activity nor activity by a relatively high membrane tension. To understand the underlying mechanism, we conducted MD simulations and analyzed the force transduction pathway. Results showed that the mutation at the tension sensor (F78N) in TM2 caused decreased interaction of this residue not only with lipids, but also with a group of amino acids (Ile32-Leu36-Ile40) in the neighboring TM1 helix, which resulted in an inefficient force transmission to the gate-constituting amino acids on TM1. This change also induced a slight tilting of TM1 towards the membrane plane and decreased the size of the channel pore at the gate, which seems to be the major mechanism for the inhibition of spontaneous opening of the double mutant channel. More importantly, the newly identified interaction between the TM2 (Phe78) and adjacent TM1 (Ile32-Leu36-Ile40) helices seems to be an essential force transmitting mechanism for the stretch-dependent activation of MscL given that substitution of any one of these four amino acids with Asn resulted in severe loss-of-function MscL as reported in our previous work.
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Affiliation(s)
- Yasuyuki Sawada
- Department of Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
- Institute of Materials Innovation, Institutes of Innovation for Future Society, Nagoya University, Nagoya, Japan
| | - Takeshi Nomura
- International Cooperative Research Project, Solution Oriented Research for Science and Technology (ICORP/SORST), Cell Mechanosensing, Japan Science and Technology Agency (JST), Nagoya, Japan
- Molecular Cardiology and Biophysics Division, Mechanosensory Biophysics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
- School of Human Science and Environment, University of Hyogo, Himeji, Japan
| | - Boris Martinac
- Molecular Cardiology and Biophysics Division, Mechanosensory Biophysics Laboratory, Victor Chang Cardiac Research Institute, Darlinghurst, NSW, Australia
| | - Masahiro Sokabe
- Department of Physiology, Nagoya University Graduate School of Medicine, Nagoya, Japan
- International Cooperative Research Project, Solution Oriented Research for Science and Technology (ICORP/SORST), Cell Mechanosensing, Japan Science and Technology Agency (JST), Nagoya, Japan
- Human Information Systems Laboratories, Kanazawa Institute of Technology, Hakusan, Ishikawa, Japan
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Yu D, Ahmed A, Jayasi J, Womac A, Sally O, Bae C. Inflammation condition sensitizes Piezo1 mechanosensitive channel in mouse cerebellum astrocyte. Front Cell Neurosci 2023; 17:1200946. [PMID: 37305437 PMCID: PMC10248153 DOI: 10.3389/fncel.2023.1200946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 05/12/2023] [Indexed: 06/13/2023] Open
Abstract
Piezo1 mechanosensitive ion channel (MSC) plays a significant role in human physiology. Despite several research on the function and expression of Piezo1 in the nervous system, its electrophysiological properties in neuroinflammatory astrocytes remain unknown. We tested whether astrocytic neuroinflammatory state regulates Piezo1 using electrical recordings, calcium imaging, and wound healing assays on cultured astrocytes. In this study, we determined whether neuroinflammatory condition regulates astrocytic Piezo1 currents in astrocytes. First, we performed electrophysiological recordings on the mouse cerebellum astrocytes (C8-S) under lipopolysaccharide (LPS)-induced neuroinflammatory condition. We found that LPS treatment significantly increased MSC currents in C8-S. The half-maximal pressure of LPS treated MSC currents was left-shifted but the slope sensitivity was not altered by LPS treatment. LPS-induced increase of MSC currents were further augmented by Piezo1 agonist, Yoda1 but were normalized by Piezo1 inhibitor, GsMTx4. Furthermore, silencing Piezo1 in LPS treated C8-S normalized not only MSC currents but also calcium influx and cell migration velocity. Together, our results show that LPS sensitized Piezo1 channel in C8-S astrocytes. These findings will suggest that astrocytic Piezo1 is a determinant of neuroinflammation pathogenesis and may in turn become the foundation of further research into curing several neuronal illnesses and injury related inflammation of neuronal cells.
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6
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Sharma A, Anishkin A, Sukharev S, Vanegas JM. Tight hydrophobic core and flexible helices yield MscL with a high tension gating threshold and a membrane area mechanical strain buffer. Front Chem 2023; 11:1159032. [PMID: 37292176 PMCID: PMC10244533 DOI: 10.3389/fchem.2023.1159032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 05/08/2023] [Indexed: 06/10/2023] Open
Abstract
The mechanosensitive (MS) channel of large conductance, MscL, is the high-tension threshold osmolyte release valve that limits turgor pressure in bacterial cells in the event of drastic hypoosmotic shock. Despite MscL from Mycobacterium tuberculosis (TbMscL) being the first structurally characterized MS channel, its protective mechanism of activation at nearly-lytic tensions has not been fully understood. Here, we describe atomistic simulations of expansion and opening of wild-type (WT) TbMscL in comparison with five of its gain-of-function (GOF) mutants. We show that under far-field membrane tension applied to the edge of the periodic simulation cell, WT TbMscL expands into a funnel-like structure with trans-membrane helices bent by nearly 70°, but does not break its 'hydrophobic seal' within extended 20 μs simulations. GOF mutants carrying hydrophilic substitutions in the hydrophobic gate of increasing severity (A20N, V21A, V21N, V21T and V21D) also quickly transition into funnel-shaped conformations but subsequently fully open within 1-8 μs. This shows that solvation of the de-wetted (vapor-locked) constriction is the rate-limiting step in the gating of TbMscL preceded by area-buffering silent expansion. Pre-solvated gates in these GOF mutants reduce this transition barrier according to hydrophilicity and the most severe V21D eliminates it. We predict that the asymmetric shape-change of the periplasmic side of the channel during the silent expansion provides strain-buffering to the outer leaflet thus re-distributing the tension to the inner leaflet, where the gate resides.
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Affiliation(s)
- Arjun Sharma
- Department of Physics, University of Vermont, Burlington, VT, United States
| | - Andriy Anishkin
- Department of Biology, University of Maryland, College Park, MD, United States
| | - Sergei Sukharev
- Department of Biology, University of Maryland, College Park, MD, United States
| | - Juan M. Vanegas
- Department of Physics, University of Vermont, Burlington, VT, United States
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7
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Lane BJ, Pliotas C. Approaches for the modulation of mechanosensitive MscL channel pores. Front Chem 2023; 11:1162412. [PMID: 37021145 PMCID: PMC10069478 DOI: 10.3389/fchem.2023.1162412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 03/03/2023] [Indexed: 03/17/2023] Open
Abstract
MscL was the first mechanosensitive ion channel identified in bacteria. The channel opens its large pore when the turgor pressure of the cytoplasm increases close to the lytic limit of the cellular membrane. Despite their ubiquity across organisms, their importance in biological processes, and the likelihood that they are one of the oldest mechanisms of sensory activation in cells, the exact molecular mechanism by which these channels sense changes in lateral tension is not fully understood. Modulation of the channel has been key to understanding important aspects of the structure and function of MscL, but a lack of molecular triggers of these channels hindered early developments in the field. Initial attempts to activate mechanosensitive channels and stabilize functionally relevant expanded or open states relied on mutations and associated post-translational modifications that were often cysteine reactive. These sulfhydryl reagents positioned at key residues have allowed the engineering of MscL channels for biotechnological purposes. Other studies have modulated MscL by altering membrane properties, such as lipid composition and physical properties. More recently, a variety of structurally distinct agonists have been shown bind to MscL directly, close to a transmembrane pocket that has been shown to have an important role in channel mechanical gating. These agonists have the potential to be developed further into antimicrobial therapies that target MscL, by considering the structural landscape and properties of these pockets.
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Affiliation(s)
- Benjamin J. Lane
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Christos Pliotas
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic and Health Science Centre, The University of Manchester, Manchester, United Kingdom
- Manchester Institute of Biotechnology, The University of Manchester, Manchester, United Kingdom
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8
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Abstract
Plasma membrane tension functions as a global physical organizer of cellular activities. Technical limitations of current membrane tension measurement techniques have hampered in-depth investigation of cellular membrane biophysics and the role of plasma membrane tension in regulating cellular processes. Here, we develop an optical membrane tension reporter by repurposing an E. coli mechanosensitive channel via insertion of circularly permuted GFP (cpGFP), which undergoes a large conformational rearrangement associated with channel activation and thus fluorescence intensity changes under increased membrane tension.
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Affiliation(s)
- Yen-Yu Hsu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Agnes M Resto Irizarry
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jianping Fu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Cell & Developmental Biology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Allen P Liu
- Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Biophysics, University of Michigan, Ann Arbor, Michigan 48109, United States
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, Michigan 48109, United States
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9
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Chen J, Rodriguez M, Miao J, Liao J, Jain PP, Zhao M, Zhao T, Babicheva A, Wang Z, Parmisano S, Powers R, Matti M, Paquin C, Soroureddin Z, Shyy JYJ, Thistlethwaite PA, Makino A, Wang J, Yuan JXJ. Mechanosensitive channel Piezo1 is required for pulmonary artery smooth muscle cell proliferation. Am J Physiol Lung Cell Mol Physiol 2022; 322:L737-L760. [PMID: 35318857 PMCID: PMC9076422 DOI: 10.1152/ajplung.00447.2021] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/10/2022] [Accepted: 03/17/2022] [Indexed: 01/10/2023] Open
Abstract
Concentric pulmonary vascular wall thickening due partially to increased pulmonary artery (PA) smooth muscle cell (PASMC) proliferation contributes to elevating pulmonary vascular resistance (PVR) in patients with pulmonary hypertension (PH). Although pulmonary vasoconstriction may be an early contributor to increasing PVR, the transition of contractile PASMCs to proliferative PASMCs may play an important role in the development and progression of pulmonary vascular remodeling in PH. A rise in cytosolic Ca2+ concentration ([Ca2+]cyt) is a trigger for PASMC contraction and proliferation. Here, we report that upregulation of Piezo1, a mechanosensitive cation channel, is involved in the contractile-to-proliferative phenotypic transition of PASMCs and potential development of pulmonary vascular remodeling. By comparing freshly isolated PA (contractile PASMCs) and primary cultured PASMCs (from the same rat) in a growth medium (proliferative PASMCs), we found that Piezo1, Notch2/3, and CaSR protein levels were significantly higher in proliferative PASMCs than in contractile PASMCs. Upregulated Piezo1 was associated with an increase in expression of PCNA, a marker for cell proliferation, whereas downregulation (with siRNA) or inhibition (with GsMTx4) of Piezo1 attenuated PASMC proliferation. Furthermore, Piezo1 in the remodeled PA from rats with experimental PH was upregulated compared with PA from control rats. These data indicate that PASMC contractile-to-proliferative phenotypic transition is associated with the transition or adaptation of membrane channels and receptors. Upregulated Piezo1 may play a critical role in PASMC phenotypic transition and PASMC proliferation. Upregulation of Piezo1 in proliferative PASMCs may likely be required to provide sufficient Ca2+ to assure nuclear/cell division and PASMC proliferation, contributing to the development and progression of pulmonary vascular remodeling in PH.
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Affiliation(s)
- Jiyuan Chen
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
- State Key Laboratory of Respiratory Disease and First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Marisela Rodriguez
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Jinrui Miao
- State Key Laboratory of Respiratory Disease and First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jing Liao
- State Key Laboratory of Respiratory Disease and First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Pritesh P Jain
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Manjia Zhao
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Tengteng Zhao
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Aleksandra Babicheva
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Ziyi Wang
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
- State Key Laboratory of Respiratory Disease and First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Sophia Parmisano
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Ryan Powers
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Moreen Matti
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Cole Paquin
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Zahra Soroureddin
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - John Y-J Shyy
- Division of Cardiovascular Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Patricia A Thistlethwaite
- Division of Cardiothoracic Surgery, Department of Surgery, University of California, San Diego, La Jolla, California
| | - Ayako Makino
- Division of Endocrinology and Metabolism, Department of Medicine, University of California, San Diego, La Jolla, California
| | - Jian Wang
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
- State Key Laboratory of Respiratory Disease and First Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Jason X-J Yuan
- Section of Physiology, Division of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, La Jolla, California
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10
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Qian N, Li S, Tan X. The curious case of TMEM120A: Mechanosensor, fat regulator, or antiviral defender? Bioessays 2022; 44:e2200045. [PMID: 35419854 DOI: 10.1002/bies.202200045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 03/17/2022] [Accepted: 03/23/2022] [Indexed: 11/06/2022]
Abstract
Mechanical pain sensing, adipogenesis, and STING-dependent innate immunity seem three distinct biological processes without substantial relationships. Intriguingly, TMEM120A, a transmembrane protein, has been shown to detect mechanical pain stimuli as a mechanosensitive channel, contribute to adipocyte differentiation/function by regulating genome organization and promote STING trafficking to active cellular innate immune response. However, the role of TMEM120A as a mechanosensitive channel was challenged by recent studies which cannot reproduce data supporting its role in mechanosensing. Furthermore, the molecular mechanism by which TMEM120A contributes to adipocyte differentiation/function and promotes STING trafficking remains elusive. In this review, we discuss these multiple proposed functions of TMEM120A and hypothesize the molecular mechanism underlying TMEM120A's role in fatty acid metabolism and STING signaling.
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Affiliation(s)
- Nianchao Qian
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Shuo Li
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China
| | - Xu Tan
- Beijing Advanced Innovation Center for Structural Biology, Beijing Frontier Research Center for Biological Structure, MOE Key Laboratory of Bioorganic Phosphorus Chemistry & Chemical Biology, School of Pharmaceutical Sciences, Tsinghua University, Beijing, China.,Tsinghua-Peking Center for Life Sciences, Beijing, China.,Center for Infectious Disease Research, School of Medicine, Tsinghua University, Beijing, China
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11
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Nie Z, Liu P, Wang Y, Guo X, Tan Z, Shen J, Tang Z, Lin J, Sun J, Zheng P, Zhu L. Directed Evolution and Rational Design of Mechanosensitive Channel MscCG2 for Improved Glutamate Excretion Efficiency. J Agric Food Chem 2021; 69:15660-15669. [PMID: 34928605 DOI: 10.1021/acs.jafc.1c07086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Mechanosensitive amino acid exporters have drawn increasing attention due to their important roles in extracellular accumulation of the target amino acids. Protein engineering is a powerful approach to tailor the properties of amino acid exporters and illustrate structure-function relationships. Here we report the first protein engineering effort on the mechanosensitive glutamate exporter MscCG2 from Corynebacterium glutamicum for improved excretion efficiency of glutamate and understanding of the structure-function relationship. MscCG2 was engineered through directed evolution and computer-assisted design with a coupled assay in microtiter plate format. Improved MscCG2 variants were identified with up to 2.5-fold increase in the level of glutamate excretion in the early stage of fermentation and 1.5-fold in the late stage of fermentation under experimental conditions. Furthermore, the identified variants exhibited enhanced efflux of 4-fluoroglutamate (4-FG), an analog of glutamate. Structure analysis employing homology modeling and molecular dynamics (MD) simulation reveal that identified amino acid substitutions enlarge the size of the seven portals on the equator of MscCG2 and expand the narrowest rim of its inner channel, respectively. This study demonstrates the great potential of protein engineering in improving the secretion efficiency of exporters for enhanced bioproduction.
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Affiliation(s)
- Zhihua Nie
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Pi Liu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Yu Wang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Xuan Guo
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zijian Tan
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jie Shen
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Zijing Tang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jianping Lin
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Jibin Sun
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Ping Zheng
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
| | - Leilei Zhu
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
- National Technology Innovation Center of Synthetic Biology, Tianjin 300308, China
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12
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Wee J, Pak S, Kim T, Hong GS, Lee JS, Nan J, Kim H, Lee MO, Park KS, Oh U. Tentonin 3/TMEM150C regulates glucose-stimulated insulin secretion in pancreatic β-cells. Cell Rep 2021; 37:110067. [PMID: 34852221 DOI: 10.1016/j.celrep.2021.110067] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 10/17/2021] [Accepted: 11/08/2021] [Indexed: 11/24/2022] Open
Abstract
Glucose homeostasis is initially regulated by the pancreatic hormone insulin. Glucose-stimulated insulin secretion in β-cells is composed of two cellular mechanisms: a high glucose concentration not only depolarizes the membrane potential of the β-cells by ATP-sensitive K+ channels but also induces cell inflation, which is sufficient to release insulin granules. However, the molecular identity of the stretch-activated cation channel responsible for the latter pathway remains unknown. Here, we demonstrate that Tentonin 3/TMEM150C (TTN3), a mechanosensitive channel, contributes to glucose-stimulated insulin secretion by mediating cation influx. TTN3 is expressed specifically in β-cells and mediates cation currents to glucose and hypotonic stimulations. The glucose-induced depolarization, firing activity, and Ca2+ influx of β-cells were significantly lower in Ttn3-/- mice. More importantly, Ttn3-/- mice show impaired glucose tolerance with decreased insulin secretion in vivo. We propose that TTN3, as a stretch-activated cation channel, contributes to glucose-stimulated insulin secretion.
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13
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Liu J, Ganeshbabu N, Shalaby N, Chen L, Guo T, Feng B. Targeting Two-Pore-Domain Potassium Channels by Mechanical Stretch Instantaneously Modulates Action Potential Transmission in Mouse Sciatic Nerves. ACS Chem Neurosci 2021; 12:3558-3566. [PMID: 34423641 DOI: 10.1021/acschemneuro.1c00052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Recent reports indicate dominant roles of TRAAK and TREK-1 channels, i.e., mechanosensitive two-pore-domain potassium channels (K2P) at the nodes of Ranvier for action potential repolarization in mammalian peripheral nerves. Functional changes in mammalian peripheral nerve conduction by mechanical stretch studied by recording compound action potentials lack the necessary resolution to detect subtle neuromodulatory effects on conduction velocity. In this study, we developed a novel in vitro approach that enables single-fiber recordings from individual mouse sciatic nerve axons while delivering computer-controlled stepped stretch to the sciatic nerve trunk. Axial stretch instantaneously increased the conduction delay in both myelinated A-fibers and unmyelinated C-fibers. Increases in conduction delay linearly correlated with increases in axial stretch ratio for both A- and C-fibers. The slope of the increase in conduction delay versus stretch ratio was steeper in C-fibers than in A-fibers. Moderate axial stretch (14-19% of in vitro length) reversibly blocked 37.5% of unmyelinated C-fibers but none of the eight myelinated A-fibers tested. Application of arachidonic acid, an agonist to TRAAK and TREK-1 to sciatic nerve trunk, blocks axonal transmission in both A- and C-fibers with delayed onset and prolonged block. Also, the application of an antagonist ruthenium red showed a tendency of suppressing the stretch-evoked increase in conduction delay. These results could draw focused research on pharmacological and mechanical activation of K2P channels as a novel neuromodulatory strategy to achieve peripheral nerve block.
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Affiliation(s)
- Jia Liu
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
| | - Nishanth Ganeshbabu
- Department of Physiology and Neurobiology, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Noha Shalaby
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
| | - Longtu Chen
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
| | - Tiantian Guo
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
| | - Bin Feng
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Storrs, Connecticut 06269, United States
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14
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Barbeau S, Gilbert G, Cardouat G, Baudrimont I, Freund-Michel V, Guibert C, Marthan R, Vacher P, Quignard JF, Ducret T. Mechanosensitivity in Pulmonary Circulation: Pathophysiological Relevance of Stretch-Activated Channels in Pulmonary Hypertension. Biomolecules 2021; 11:biom11091389. [PMID: 34572602 PMCID: PMC8470538 DOI: 10.3390/biom11091389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 09/17/2021] [Accepted: 09/19/2021] [Indexed: 01/03/2023] Open
Abstract
A variety of cell types in pulmonary arteries (endothelial cells, fibroblasts, and smooth muscle cells) are continuously exposed to mechanical stimulations such as shear stress and pulsatile blood pressure, which are altered under conditions of pulmonary hypertension (PH). Most functions of such vascular cells (e.g., contraction, migration, proliferation, production of extracellular matrix proteins, etc.) depend on a key event, i.e., the increase in intracellular calcium concentration ([Ca2+]i) which results from an influx of extracellular Ca2+ and/or a release of intracellular stored Ca2+. Calcium entry from the extracellular space is a major step in the elevation of [Ca2+]i, involving a variety of plasmalemmal Ca2+ channels including the superfamily of stretch-activated channels (SAC). A common characteristic of SAC is that their gating depends on membrane stretch. In general, SAC are non-selective Ca2+-permeable cation channels, including proteins of the TRP (Transient Receptor Potential) and Piezo channel superfamily. As membrane mechano-transducers, SAC convert physical forces into biological signals and hence into a cell response. Consequently, SAC play a major role in pulmonary arterial calcium homeostasis and, thus, appear as potential novel drug targets for a better management of PH.
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Affiliation(s)
- Solène Barbeau
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Guillaume Gilbert
- ORPHY, UFR Sciences et Techniques, University of Brest, EA 4324, F-29238 Brest, France;
| | - Guillaume Cardouat
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Isabelle Baudrimont
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Véronique Freund-Michel
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Christelle Guibert
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Roger Marthan
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Pierre Vacher
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Jean-François Quignard
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
| | - Thomas Ducret
- Centre de Recherche Cardio-Thoracique de Bordeaux, Univ. Bordeaux, U1045, F-33600 Pessac, France; (S.B.); (G.C.); (I.B.); (V.F.-M.); (C.G.); (R.M.); (P.V.); (J.-F.Q.)
- INSERM, Centre de Recherche Cardio-Thoracique de Bordeaux, U1045, F-33600 Pessac, France
- Correspondence:
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15
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Matsunaga M, Kimura M, Ouchi T, Nakamura T, Ohyama S, Ando M, Nomura S, Azuma T, Ichinohe T, Shibukawa Y. Mechanical Stimulation-Induced Calcium Signaling by Piezo1 Channel Activation in Human Odontoblast Reduces Dentin Mineralization. Front Physiol 2021; 12:704518. [PMID: 34504437 PMCID: PMC8421527 DOI: 10.3389/fphys.2021.704518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/03/2021] [Indexed: 11/13/2022] Open
Abstract
Odontoblasts play critical roles in dentin formation and sensory transduction following stimuli on the dentin surface. Exogenous stimuli to the dentin surface elicit dentinal sensitivity through the movement of fluids in dentinal tubules, resulting in cellular deformation. Recently, Piezo1 channels have been implicated in mechanosensitive processes, as well as Ca2+ signals in odontoblasts. However, in human odontoblasts, the cellular responses induced by mechanical stimulation, Piezo1 channel expression, and its pharmacological properties remain unclear. In the present study, we examined functional expression of the Piezo1 channel by recording direct mechanical stimulation-induced Ca2+ signaling in dentin matrix protein 1 (DMP-1)-, nestin-, and dentin sialophosphoprotein (DSPP)-immunopositive human odontoblasts. Mechanical stimulation of human odontoblasts transiently increased intracellular free calcium concentration ([Ca2+]i). Application of repeated mechanical stimulation to human odontoblasts resulted in repeated transient [Ca2+]i increases, but did not show any desensitizing effects on [Ca2+]i increases. We also observed a transient [Ca2+]i increase in the neighboring odontoblasts to the stimulated cells during mechanical stimulation, showing a decrease in [Ca2+]i with an increasing distance from the mechanically stimulated cells. Application of Yoda1 transiently increased [Ca2+]i. This increase was inhibited by application of Gd3+ and Dooku1, respectively. Mechanical stimulation-induced [Ca2+]i increase was also inhibited by application of Gd3+ or Dooku1. When Piezo1 channels in human odontoblasts were knocked down by gene silencing with short hairpin RNA (shRNA), mechanical stimulation-induced [Ca2+]i responses were almost completely abolished. Piezo1 channel knockdown attenuated the number of Piezo1-immunopositive cells in the immunofluorescence analysis, while no effects were observed in Piezo2-immunopositive cells. Alizarin red staining distinctly showed that pharmacological activation of Piezo1 channels by Yoda1 significantly suppressed mineralization, and shRNA-mediated knockdown of Piezo1 also significantly enhanced mineralization. These results suggest that mechanical stimulation predominantly activates intracellular Ca2+ signaling via Piezo1 channel opening, rather than Piezo2 channels, and the Ca2+ signal establishes intercellular odontoblast-odontoblast communication. In addition, Piezo1 channel activation participates in the reduction of dentinogenesis. Thus, the intracellular Ca2+ signaling pathway mediated by Piezo1 channels could contribute to cellular function in human odontoblasts in two ways: (1) generating dentinal sensitivity and (2) suppressing physiological/reactional dentinogenesis, following cellular deformation induced by hydrodynamic forces inside dentinal tubules.
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Affiliation(s)
- Mayumi Matsunaga
- Department of Physiology, Tokyo Dental College, Tokyo, Japan.,Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan
| | - Maki Kimura
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - Takehito Ouchi
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | | | - Sadao Ohyama
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - Masayuki Ando
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - Sachie Nomura
- Department of Physiology, Tokyo Dental College, Tokyo, Japan
| | - Toshifumi Azuma
- Department of Biochemistry, Tokyo Dental College, Tokyo, Japan
| | - Tatsuya Ichinohe
- Department of Dental Anesthesiology, Tokyo Dental College, Tokyo, Japan
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16
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Behnami S, Bonetta D. With an Ear Up against the Wall: An Update on Mechanoperception in Arabidopsis. Plants (Basel) 2021; 10:1587. [PMID: 34451632 PMCID: PMC8398075 DOI: 10.3390/plants10081587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 07/26/2021] [Accepted: 07/28/2021] [Indexed: 11/16/2022]
Abstract
Cells interpret mechanical signals and adjust their physiology or development appropriately. In plants, the interface with the outside world is the cell wall, a structure that forms a continuum with the plasma membrane and the cytoskeleton. Mechanical stress from cell wall damage or deformation is interpreted to elicit compensatory responses, hormone signalling, or immune responses. Our understanding of how this is achieved is still evolving; however, we can refer to examples from animals and yeast where more of the details have been worked out. Here, we provide an update on this changing story with a focus on candidate mechanosensitive channels and plasma membrane-localized receptors.
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Affiliation(s)
| | - Dario Bonetta
- Faculty of Science, Ontario Tech University, 2000 Simcoe St N, Oshawa, ON L1G 0C5, Canada;
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17
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Saito T, Gotoh D, Wada N, Tyagi P, Minagawa T, Ogawa T, Ishizuka O, Yoshimura N. Time-dependent progression of neurogenic lower urinary tract dysfunction after spinal cord injury in the mouse model. Am J Physiol Renal Physiol 2021; 321:F26-F32. [PMID: 33969698 DOI: 10.1152/ajprenal.00622.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 05/04/2021] [Indexed: 11/22/2022] Open
Abstract
This study evaluated the time-course changes in bladder and external urinary sphincter (EUS) activity and the expression of mechanosensitive channels in lumbosacral dorsal root ganglia (DRG) after spinal cord injury (SCI). Female C57BL/6N mice in the SCI group underwent transection of the Th8/9 spinal cord. Spinal intact mice and SCI mice at 2, 4, and 6 wk post-SCI were evaluated by single-filling cystometry and EUS-electromyography (EMG). In another set of mice, the bladder and L6-S1 DRG were harvested for protein and mRNA analyses. In SCI mice, nonvoiding contractions were confirmed at 2 wk post-SCI and did not increase over time to 6 wk. In 2-wk SCI mice, EUS-EMG measurements revealed detrusor sphincter dyssynergia, but periodic EMG reductions during bladder contraction were hardly observed. At 4 wk, SCI mice showed increases of EMG activity reduction time with increased voiding efficiency. At 6 wk, SCI mice exhibited a further increase in EMG reduction time. RT-PCR of L6-S1 DRG showed increased mRNA levels of transient receptor potential vanilloid 1 and acid-sensing ion channels (ASIC1-ASIC3) in SCI mice with a decrease of ASIC2 and ASIC3 at 6 wk compared with 4 wk, whereas Piezo2 showed a slow increase at 6 wk. Protein assay showed SCI-induced overexpression of bladder brain-derived neurotrophic factor with a time-dependent decrease post-SCI. These results indicate that detrusor overactivity is established in the early phase, whereas detrusor sphincter dyssynergia is completed later at 4 wk with an improvement at 6 wk post-SCI, and that mechanosensitive channels may be involved in the time-dependent changes.NEW & NOTEWORTHY This is the first paper to evaluate the time-course changes of bladder dysfunction associated with mechanosensitive channels in a mouse model.
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Affiliation(s)
- Tetsuichi Saito
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- Department of Urology, Shinshu University School of Medicine, Nagano, Japan
| | - Daisuke Gotoh
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Naoki Wada
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Pradeep Tyagi
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Tomonori Minagawa
- Department of Urology, Shinshu University School of Medicine, Nagano, Japan
| | - Teruyuki Ogawa
- Department of Urology, Shinshu University School of Medicine, Nagano, Japan
| | - Osamu Ishizuka
- Department of Urology, Shinshu University School of Medicine, Nagano, Japan
| | - Naoki Yoshimura
- Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
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18
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Pang JJ, Gao F, Wu SM. Generators of Pressure-Evoked Currents in Vertebrate Outer Retinal Neurons. Cells 2021; 10:cells10061288. [PMID: 34067375 PMCID: PMC8224636 DOI: 10.3390/cells10061288] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/13/2021] [Accepted: 05/19/2021] [Indexed: 12/19/2022] Open
Abstract
(1) Background: High-tension glaucoma damages the peripheral vision dominated by rods. How mechanosensitive channels (MSCs) in the outer retina mediate pressure responses is unclear. (2) Methods: Immunocytochemistry, patch clamp, and channel fluorescence were used to study MSCs in salamander photoreceptors. (3) Results: Immunoreactivity of transient receptor potential channel vanilloid 4 (TRPV4) was revealed in the outer plexiform layer, K+ channel TRAAK in the photoreceptor outer segment (OS), and TRPV2 in some rod OS disks. Pressure on the rod inner segment evoked sustained currents of three components: (A) the inward current at <-50 mV (Ipi), sensitive to Co2+; (B) leak outward current at ≥-80 mV (Ipo), sensitive to intracellular Cs+ and ruthenium red; and (C) cation current reversed at ~10 mV (Ipc). Hypotonicity induced slow currents like Ipc. Environmental pressure and light increased the FM 1-43-identified open MSCs in the OS membrane, while pressure on the OS with internal Cs+ closed a Ca2+-dependent current reversed at ~0 mV. Rod photocurrents were thermosensitive and affected by MSC blockers. (4) Conclusions: Rods possess depolarizing (TRPV) and hyperpolarizing (K+) MSCs, which mediate mutually compensating currents between -50 mV and 10 mV, serve as an electrical cushion to minimize the impact of ocular mechanical stress.
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19
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Tran D, Girault T, Guichard M, Thomine S, Leblanc-Fournier N, Moulia B, de Langre E, Allain JM, Frachisse JM. Cellular transduction of mechanical oscillations in plants by the plasma-membrane mechanosensitive channel MSL10. Proc Natl Acad Sci U S A 2021; 118:e1919402118. [PMID: 33372153 DOI: 10.1073/pnas.1919402118] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Plants spend most of their life oscillating around 1-3 Hz due to the effect of the wind. Therefore, stems and foliage experience repetitive mechanical stresses through these passive movements. However, the mechanism of the cellular perception and transduction of such recurring mechanical signals remains an open question. Multimeric protein complexes forming mechanosensitive (MS) channels embedded in the membrane provide an efficient system to rapidly convert mechanical tension into an electrical signal. So far, studies have mostly focused on nonoscillatory stretching of these channels. Here, we show that the plasma-membrane MS channel MscS-LIKE 10 (MSL10) from the model plant Arabidopsis thaliana responds to pulsed membrane stretching with rapid activation and relaxation kinetics in the range of 1 s. Under sinusoidal membrane stretching MSL10 presents a greater activity than under static stimulation. We observed this amplification mostly in the range of 0.3-3 Hz. Above these frequencies the channel activity is very close to that under static conditions. With a localization in aerial organs naturally submitted to wind-driven oscillations, our results suggest that the MS channel MSL10, and by extension MS channels sharing similar properties, represents a molecular component allowing the perception of oscillatory mechanical stimulations by plants.
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20
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Roterman I, Stapor K, Fabian P, Konieczny L, Banach M. Model of Environmental Membrane Field for Transmembrane Proteins. Int J Mol Sci 2021; 22:ijms22073619. [PMID: 33807215 PMCID: PMC8036355 DOI: 10.3390/ijms22073619] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/20/2021] [Accepted: 03/27/2021] [Indexed: 11/16/2022] Open
Abstract
The water environment determines the activity of biological processes. The role of such an environment interpreted in the form of an external field expressed by the 3D Gaussian distribution in the fuzzy oil drop model directs the folding process towards the generation of a centrally located hydrophobic core with the simultaneous exposure of polar residues on the surface. In addition to proteins soluble in the water environment, there is a significant group of membrane proteins that act as receptors or channels, including ion channels in particular. The change of the polar (water) environment into a highly hydrophobic (membrane) environment is quite radical, resulting in a different hydrophobicity distribution within the membrane protein. Modification of the notation of the force field expressing the presence of the hydrophobic environment has been proposed in this work. A modified fuzzy oil drop model with its adaptation to membrane proteins was used to interpret the structure of membrane proteins–mechanosensitive channel. The modified model was also used to describe the so-called negative cases—i.e., for water-soluble proteins with a clear distribution consistent with the fuzzy oil drop model.
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Affiliation(s)
- Irena Roterman
- Department of Bioinformatics and Telemedicine, Jagiellonian University—Medical College, 30-688 Kraków, Poland;
- Correspondence:
| | - Katarzyna Stapor
- Institute of Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland; (K.S.); (P.F.)
| | - Piotr Fabian
- Institute of Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland; (K.S.); (P.F.)
| | - Leszek Konieczny
- Chair of Medical Biochemistry, Jagiellonian University—Medical College, 31-034 Kraków, Poland;
| | - Mateusz Banach
- Department of Bioinformatics and Telemedicine, Jagiellonian University—Medical College, 30-688 Kraków, Poland;
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21
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Yamaguchi S, Hamamura M, Otsuguro K. A Mechanosensitive Channel, Mouse Transmembrane Channel-Like Protein 1 (Mtmc1) Is Translated from a Splice Variant mTmc1ex1 but Not from the Other Variant mTmc1ex2. Int J Mol Sci 2020; 21:E6465. [PMID: 32899784 DOI: 10.3390/ijms21186465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 08/29/2020] [Accepted: 09/02/2020] [Indexed: 11/17/2022] Open
Abstract
Mechanical stimuli caused by sound waves are detected by hair cells in the cochlea through the opening of mechanoelectrical transduction (MET) channels. Transmembrane channel-like protein 1 (TMC1) has been revealed to be the pore-forming component of the MET channel. The two splice variants for mouse Tmc1 (mTmc1ex1 and mTmc1ex2) were reported to be expressed in the cochlea of infant mice, though only the sequence of mTmc1ex2 had been deposited in GenBank. However, due to the presence of an upstream open reading frame (uORF) and the absence of a typical Kozak sequence in mTmc1ex2, we questioned whether mTMC1 was translated from mTmc1ex2. Therefore, in this study, we evaluated which splice variant was protein-coding mRNA. Firstly, the results of RT-PCR and cDNA cloning of mTmc1 using mRNA isolated from the cochlea of five-week-old mice suggested that more Tmc1ex1 were expressed than mTmc1ex2. Secondly, mTMC1 was translated from mTmc1ex1 but not from mTmc1ex2 in a heterologous expression system. Finally, analyses using site-directed mutagenesis revealed that the uORF and the weak Kozak sequence in mTmc1ex2 prevented the translation of mTMC1 from mTmc1ex2. These results suggest that mTmc1ex1 plays a main role in the expression of mTMC1 in the mouse cochlea, and therefore, mTmc1ex1 should be the mRNA for mTMC1 hereafter.
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Chainani A, Matson A, Chainani M, Marchand Colon AJ, Toth AP, Garrigues GE, Little D. Contracture and transient receptor potential channel upregulation in the anterior glenohumeral joint capsule of patients with end-stage osteoarthritis. J Shoulder Elbow Surg 2020; 29:e253-e268. [PMID: 32113865 DOI: 10.1016/j.jse.2019.11.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 11/15/2019] [Accepted: 11/23/2019] [Indexed: 02/06/2023]
Abstract
BACKGROUND During anatomic total shoulder arthroplasty (TSA) for primary glenohumeral osteoarthritis (GHOA), the anterior shoulder joint capsule (ASJC) is characterized grossly by contracture, synovitis, and fibrosis. In tissues that develop fibrosis, there is substantial cross-talk between macrophages, fibroblasts, and myofibroblasts, modulated by calcium signaling and transient receptor potential (TRP) channel signaling. The purpose of this study was to compare and characterize the degree of synovitis, inflammatory infiltrate, and TRP channel expression in ASJC harvested from shoulders with and without primary GHOA. METHODS The ASJC was resected from patients undergoing TSA for primary GHOA or other diagnoses and compared with ASJC from cadaveric donors with no history of shoulder pathology. ASJC was evaluated by immunohistochemistry to characterize synovial lining and capsular inflammatory cell infiltrate and fibrosis, and to evaluate for expression of TRPA1, TRPV1, and TRPV4, known to be involved in fibrosis in other tissues. Blinded sections were evaluated by 3 graders using a semiquantitative scale; then results were compared between diagnosis groups using nonparametric methods. RESULTS Compared with normal control, the ASJC in primary GHOA had significantly increased synovitis, fibrosis, mixed inflammatory cell infiltrate including multiple macrophages subsets, and upregulation of TRP channel expression. CONCLUSION These data support the clinical findings of ASJC and synovial fibrosis in primary GHOA, identify a mixed inflammatory response, and identify dysregulation of TRP channels in the synovium and joint capsule. Further studies will identify the role of synovial and capsular fibrosis early in the development of GHOA.
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Affiliation(s)
- Abby Chainani
- Department of Surgery, University of Iowa, Iowa City, IA, USA
| | - Andrew Matson
- Department of Orthopaedic Surgery, Brigham and Women's Hospital, Boston, MA, USA
| | - Masoom Chainani
- Medical College of Georgia at Augusta University, Augusta, GA, USA
| | | | - Alison P Toth
- Department of Orthopaedic Surgery, Duke University Medical Center, Durham, NC, USA
| | - Grant E Garrigues
- Midwest Orthopaedics at Rush, Rush University Medical Center, Chicago, IL, USA
| | - Dianne Little
- Departments of Basic Medical Sciences and Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
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Hattori T, Otomi Y, Nakajima Y, Soga K, Wakabayashi K, Iida H, Hoson T. MCA1 and MCA2 Are Involved in the Response to Hypergravity in Arabidopsis Hypocotyls. Plants (Basel) 2020; 9:E590. [PMID: 32380659 DOI: 10.3390/plants9050590] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Revised: 04/30/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022]
Abstract
Plants respond to and resist gravitational acceleration, but the mechanism of signal perception in the response is unknown. We studied the role of MCA (mid1-complementing activity) proteins in gravity perception by analyzing the expression of the MCA1 and MCA2 genes, and the growth of hypocotyls of mca mutants, under hypergravity conditions in the dark. An MCA1 promoter::GUS fusion reporter gene construct (MCA1p::GUS) and MCA2p::GUS were expressed almost universally in etiolated seedlings. Under hypergravity conditions, the expression levels of both genes increased compared with that under the 1 g condition, and remained higher, especially in the basal supporting region. On the other hand, mca-null and MCA-overexpressing seedlings showed normal growth under the 1 g condition. Hypergravity suppressed elongation growth of hypocotyls, but this effect was reduced in hypocotyls of mca-null mutants compared with the wild type. In contrast, MCA-overexpressing seedlings were hypersensitive to increased gravity; suppression of elongation growth was detected at a lower gravity level than that in the wild type. These results suggest that MCAs are involved in the perception of gravity signals in plants, and may be responsible for resistance to hypergravity.
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Abstract
Activation of mechanosensitive ion channels underlies a variety of fundamental physiological processes that require sensation of mechanical force. Different mechanosensitive channels adapt distinctive structures and mechanotransduction mechanisms to fit their biological roles. How mechanosensitive channels work, especially in animals, has been extensively studied in the past decade. Here we review key findings in the functional and structural characterizations of these channels and highlight the structural features relevant to the mechanotransduction mechanism of each specific channel.
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Affiliation(s)
- Peng Jin
- Department of Physiology, University of California, San Francisco, California 94158, USA;
| | - Lily Yeh Jan
- Department of Physiology, University of California, San Francisco, California 94158, USA; .,Department of Biochemistry and Biophysics and Howard Hughes Medical Institute, University of California, San Francisco, California 94158, USA
| | - Yuh-Nung Jan
- Department of Physiology, University of California, San Francisco, California 94158, USA; .,Department of Biochemistry and Biophysics and Howard Hughes Medical Institute, University of California, San Francisco, California 94158, USA
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25
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Zhang M, Li X, Zheng H, Wen X, Chen S, Ye J, Tang S, Yao F, Li Y, Yan Z. Brv1 Is Required for Drosophila Larvae to Sense Gentle Touch. Cell Rep 2019; 23:23-31. [PMID: 29617663 DOI: 10.1016/j.celrep.2018.03.041] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/20/2018] [Accepted: 03/09/2018] [Indexed: 01/16/2023] Open
Abstract
How we sense touch is fundamental for many physiological processes. However, the underlying mechanism and molecular identity for touch sensation are largely unknown. Here, we report on defective gentle-touch behavioral responses in brv1 loss-of-function Drosophila larvae. RNAi and Ca2+ imaging confirmed the involvement of Brv1 in sensing touch and demonstrated that Brv1 mediates the mechanotransduction of class III dendritic arborization neurons. Electrophysiological recordings further revealed that the expression of Brv1 protein in HEK293T cells gives rise to stretch-activated cation channels. Purified Brv1 protein reconstituted into liposomes were found to sense stretch stimuli. In addition, co-expression studies suggested that Brv1 amplifies the response of mechanosensitive ion channel NOMPC (no mechanoreceptor potential C) to touch stimuli. Altogether, these findings demonstrate a molecular entity that mediates the gentle-touch response in Drosophila larvae, providing insights into the molecular mechanisms of touch sensation.
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Affiliation(s)
- Mingfeng Zhang
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China; State Key Laboratory of Medical Neurobiology, Human Phenome Institute, Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xia Li
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Honglan Zheng
- State Key Laboratory of Medical Neurobiology, Human Phenome Institute, Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Xiaoxu Wen
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Sihan Chen
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Jia Ye
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Siyang Tang
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Fuqiang Yao
- State Key Laboratory of Medical Neurobiology, Human Phenome Institute, Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yuezhou Li
- Children's Hospital and Institute of Neuroscience, Key Laboratory of Medical Neurobiology of Ministry of Health of China, Zhejiang University School of Medicine, Hangzhou 310058, China.
| | - Zhiqiang Yan
- State Key Laboratory of Medical Neurobiology, Human Phenome Institute, Ministry of Education Key Laboratory of Contemporary Anthropology, Collaborative Innovation Center of Genetics and Development, Institute of Brain Science, Department of Physiology and Biophysics, School of Life Sciences, Fudan University, Shanghai 200438, China.
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26
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Owada N, Yoshida M, Morita K, Yoshimura K. Temperature-sensitive mutants of MscL mechanosensitive channel. J Biochem 2019; 166:281-288. [PMID: 31143940 DOI: 10.1093/jb/mvz035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Accepted: 04/25/2019] [Indexed: 01/15/2023] Open
Abstract
MscL is a mechanosensitive channel that undergoes a global conformational change upon application of membrane stretching. To elucidate how the structural stability and flexibility occur, we isolated temperature-sensitive (Ts) mutants of Escherichia coli MscL that allowed cell growth at 32°C but not at 42°C. Two Ts mutants, L86P and D127V, were identified. The L86P mutation occurred in the second transmembrane helix, TM2. Substitution of residues neighbouring L86 with proline also led to a Ts mutation, but the substitution of L86 with other amino acids did not result in a Ts phenotype, indicating that the Ts phenotype was due to a structural change of TM2 helix by the introduction of a proline residue. The D127V mutation was localized in the electrostatic belt of the bundle of cytoplasmic helices, indicating that stability of the pentameric bundle of the cytoplasmic helix affects MscL structure. Together, this study described a novel class of MscL mutations that were correlated with the thermodynamic stability of the MscL structure.
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Affiliation(s)
- Naoto Owada
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
| | - Megumi Yoshida
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
| | - Kohei Morita
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
| | - Kenjiro Yoshimura
- Department of Machinery and Control Systems, College of Systems Engineering and Science, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama, Japan
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27
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Amemiya S, Toyoda H, Kimura M, Saito H, Kobayashi H, Ihara K, Kamagata K, Kawabata R, Kato S, Nakashimada Y, Furuta T, Hamamoto S, Uozumi N. The mechanosensitive channel YbdG from Escherichia coli has a role in adaptation to osmotic up-shock. J Biol Chem 2019; 294:12281-12292. [PMID: 31256002 DOI: 10.1074/jbc.ra118.007340] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 06/20/2019] [Indexed: 01/24/2023] Open
Abstract
Mechanosensitive channels play an important role in the adaptation of cells to hypo-osmotic shock. Among members of this channel family in Escherichia coli, the exact function and physiological role of the mechanosensitive channel homolog YbdG remain unclear. Characterization of YbdG's physiological role has been hampered by its lack of measurable transport activity. Using a nitrosoguanidine mutagenesis-aided screen in combination with next-generation sequencing, here we isolated a mutant with a point mutation in ybdG This mutation (resulting in a I167T change) conferred sensitivity to high osmotic stress, and the mutant cells differed from WT cells in morphology during hyperosmotic stress at alkaline pH. Interestingly, unlike the cells containing the I167T variant, a null-ybdG mutant did not exhibit this sensitivity and phenotype. Although I167T was located near the putative ion-conducting pore in a transmembrane region of YbdG, no change in ion channel activities of YbdG-I167T was detected. Of note, introduction of the WT C-terminal cytosolic region of YbdG into the I167T variant complemented the osmo-sensitive phenotype. Co-precipitation of proteins interacting with the C-terminal YbdG region led to the isolation of HldD and FbaA, whose overexpression in cells containing the YbdG-I167T variant partially rescued the osmo-sensitive phenotype. This study indicates that YbdG functions as a component of a mechanosensing system that transmits signals triggered by external osmotic changes to intracellular factors. The cellular role of YbdG uncovered here goes beyond its predicted function as an ion or solute transport protein.
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Affiliation(s)
- Shun Amemiya
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan
| | - Hayato Toyoda
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan
| | - Mami Kimura
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan
| | - Hiromi Saito
- Department of Biochemistry, Graduate School of Pharmaceutical Science, Chiba University, Chiba 260-8675, Japan
| | - Hiroshi Kobayashi
- Department of Biochemistry, Graduate School of Pharmaceutical Science, Chiba University, Chiba 260-8675, Japan
| | - Kunio Ihara
- Center for Gene Research, Nagoya University, Nagoya 464-8602, Japan
| | - Kiyoto Kamagata
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan
| | - Ryuji Kawabata
- School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan
| | - Setsu Kato
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
| | - Yutaka Nakashimada
- Department of Molecular Biotechnology, Graduate School of Advanced Sciences of Matter, Hiroshima University, Higashi-Hiroshima 739-8530, Japan
| | - Tadaomi Furuta
- School of Life Science and Technology, Tokyo Institute of Technology, B-62 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8501, Japan
| | - Shin Hamamoto
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan
| | - Nobuyuki Uozumi
- Department of Biomolecular Engineering, Graduate School of Engineering, Tohoku University, Aobayama 6-6-07, Sendai 980-8579, Japan.
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28
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Li H, Xu J, Shen ZS, Wang GM, Tang M, Du XR, Lv YT, Wang JJ, Zhang FF, Qi Z, Zhang Z, Sokabe M, Tang QY. The neuropeptide GsMTx4 inhibits a mechanosensitive BK channel through the voltage-dependent modification specific to mechano-gating. J Biol Chem 2019; 294:11892-11909. [PMID: 31201274 DOI: 10.1074/jbc.ra118.005511] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 06/06/2019] [Indexed: 12/12/2022] Open
Abstract
The cardiac mechanosensitive BK (Slo1) channels are gated by Ca2+, voltage, and membrane stretch. The neuropeptide GsMTx4 is a selective inhibitor of mechanosensitive (MS) channels. It has been reported to suppress stretch-induced cardiac fibrillation in the heart, but the mechanism underlying the specificity and even the targeting channel(s) in the heart remain elusive. Here, we report that GsMTx4 inhibits a stretch-activated BK channel (SAKcaC) in the heart through a modulation specific to mechano-gating. We show that membrane stretching increases while GsMTx4 decreases the open probability (P o) of SAKcaC. These effects were mostly abolished by the deletion of the STREX axis-regulated (STREX) exon located between RCK1 and RCK2 domains in BK channels. Single-channel kinetics analysis revealed that membrane stretch activates SAKcaC by prolonging the open-time duration (τO) and shortening the closed-time constant (τC). In contrast, GsMTx4 reversed the effects of membrane stretch, suggesting that GsMTx4 inhibits SAKcaC activity by interfering with mechano-gating of the channel. Moreover, GsMTx4 exerted stronger efficacy on SAKcaC under membrane-hyperpolarized/resting conditions. Molecular dynamics simulation study revealed that GsMTx4 appeared to have the ability to penetrate deeply within the bilayer, thus generating strong membrane deformation under the hyperpolarizing/resting conditions. Immunostaining results indicate that BK variants containing STREX are also expressed in mouse ventricular cardiomyocytes. Our results provide common mechanisms of peptide actions on MS channels and may give clues to therapeutic suppression of cardiac arrhythmias caused by excitatory currents through MS channels under hyper-mechanical stress in the heart.
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Affiliation(s)
- Hui Li
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Jie Xu
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Zhong-Shan Shen
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Guang-Ming Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Mingxi Tang
- Department of Pathology, Affiliated Hospital of Southwest Medical University, Luzhou, Sichuan Province 646000, China
| | - Xiang-Rong Du
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Yan-Tian Lv
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Jing-Jing Wang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Fei-Fei Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Zhi Qi
- Department of Basic Medical Sciences, Medical College of Xiamen University, Xiamen 361102, China
| | - Zhe Zhang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China
| | - Masahiro Sokabe
- ICORP Cell Mechanosensing, Japan Science and Technology Agency, Nagoya 466-8550, Japan .,Mechanobiology Laboratory, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Japan.,Department of Physiology, Nagoya University, Graduate School of Medicine, Nagoya 466-8550, Japan
| | - Qiong-Yao Tang
- Jiangsu Province Key Laboratory of Anesthesiology, Xuzhou Medical University, Xuzhou, Jiangsu Province 221004, China .,ICORP Cell Mechanosensing, Japan Science and Technology Agency, Nagoya 466-8550, Japan
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29
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Lee JS, Wilson ME, Richardson RA, Haswell ES. Genetic and physical interactions between the organellar mechanosensitive ion channel homologs MSL1, MSL2, and MSL3 reveal a role for inter-organellar communication in plant development. Plant Direct 2019; 3:e00124. [PMID: 31245767 PMCID: PMC6508831 DOI: 10.1002/pld3.124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/24/2019] [Accepted: 02/11/2019] [Indexed: 05/31/2023]
Abstract
Plant development requires communication on many levels, including between cells and between organelles within a cell. For example, mitochondria and plastids have been proposed to be sensors of environmental stress and to coordinate their responses. Here we present evidence for communication between mitochondria and chloroplasts during leaf and root development, based on genetic and physical interactions between three Mechanosensitive channel of Small conductance-Like (MSL) proteins from Arabidopsis thaliana. MSL proteins are Arabidopsis homologs of the bacterial Mechanosensitive channel of Small conductance (MscS), which relieves cellular osmotic pressure to protect against lysis during hypoosmotic shock. MSL1 localizes to the inner mitochondrial membrane, while MSL2 and MSL3 localize to the inner plastid membrane and are required to maintain plastid osmotic homeostasis during normal growth and development. In this study, we characterized the phenotypic effect of a genetic lesion in MSL1, both in wild type and in msl2 msl3 mutant backgrounds. msl1 single mutants appear wild type for all phenotypes examined. The characteristic leaf rumpling in msl2 msl3 double mutants was exacerbated in the msl1 msl2 msl3 triple mutant. However, the introduction of the msl1 lesion into the msl2 msl3 mutant background suppressed other msl2 msl3 mutant phenotypes, including ectopic callus formation, accumulation of superoxide and hydrogen peroxide in the shoot apical meristem, decreased root length, and reduced number of lateral roots. All these phenotypes could be recovered by molecular complementation with a transgene containing a wild type version of MSL1. In yeast-based interaction studies, MSL1 interacted with itself, but not with MSL2 or MSL3. These results establish that the abnormalities observed in msl2 msl3 double mutants is partially dependent on the presence of functional MSL1 and suggest a possible role for communication between plastid and mitochondria in seedling development.
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Affiliation(s)
- Josephine S. Lee
- NSF Center for Engineering MechanoBiologyDepartment of BiologyWashington University in Saint LouisSaint LouisMissouri
- Present address:
Broad InstituteCambridgeMassachusetts
| | - Margaret E. Wilson
- NSF Center for Engineering MechanoBiologyDepartment of BiologyWashington University in Saint LouisSaint LouisMissouri
- Present address:
Donald Danforth Plant Science CenterSaint LouisMissouri
| | - Ryan A. Richardson
- NSF Center for Engineering MechanoBiologyDepartment of BiologyWashington University in Saint LouisSaint LouisMissouri
| | - Elizabeth S. Haswell
- NSF Center for Engineering MechanoBiologyDepartment of BiologyWashington University in Saint LouisSaint LouisMissouri
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30
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Wang X, Tang S, Wen X, Hong L, Hong F, Li Y. Transmembrane TM3b of Mechanosensitive Channel MscS Interacts With Cytoplasmic Domain Cyto-Helix. Front Physiol 2018; 9:1389. [PMID: 30327617 PMCID: PMC6174206 DOI: 10.3389/fphys.2018.01389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/12/2018] [Indexed: 11/25/2022] Open
Abstract
The mechanosensitive channel MscS functions as an osmolyte emergency release-valve in the event of a sudden decrease in external environmental osmolarity. MscS has served as a paradigm for studying how channel proteins detect and respond to mechanical stimuli. However, the inter-domain interactions and structural rearrangements that occur in the MscS gating process remain largely unknown. Here, we determined the interactions between the transmembrane domain and cytoplasmic domain of MscS. Using in vivo cellular viability, single-channel electrophysiological recording, and cysteine disulfide trapping, we demonstrated that N117 of the TM3b helix and N167 of the Cyto-helix are critical residues that function at the TM3b-Cyto helix interface. In vivo downshock assays showed that double cysteine substitution at N117 and N167 failed to rescue the osmotic-lysis phenotype of cells in acute osmotic downshock. Single-channel recordings demonstrated that cysteine cross-linking of N117C and N167C led to a non-conductive channel. Consistently, coordination of the histidines of N117H and N167H caused a decrease in channel gating. Moreover, cross-linked N117 and N167 altered the gating of the severe gain-of-function mutant L109S. Our results demonstrate that N117–N167 interactions stabilize the inactivation state by an association of TM3b segments with β-domains of the cytoplasmic region, providing further insights into the gating mechanism of the MscS channel.
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Affiliation(s)
- Xiaomin Wang
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Siyang Tang
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xiaoxu Wen
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Lang Hong
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Feifan Hong
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Yuezhou Li
- Children's Hospital and Department of Biophysics, National Health Commission and Chinese Academy of Medical Sciences Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
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31
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Guerringue Y, Thomine S, Frachisse JM. Sensing and transducing forces in plants with MSL10 and DEK1 mechanosensors. FEBS Lett 2018; 592:1968-1979. [PMID: 29782638 DOI: 10.1002/1873-3468.13102] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 04/27/2018] [Accepted: 05/05/2018] [Indexed: 12/14/2022]
Abstract
Mechanosensitive (MS) channels behave as microprobes that transduce mechanical tension into electric and ion signals. The plasma membrane anion-permeable channel AtMSL10 belongs to the first family of MS channels (MscS-LIKE) that has been characterized in Arabidopsis thaliana. In the same membrane, a rapidly activated calcium MS channel activity (RMA) associated with the presence of the DEFECTIVE KERNEL1 (AtDEK1) protein has been recently described. In this Review, based on the comparison of the specific properties of AtMSL10 and RMA, we put forward hypotheses on the mechanism of activation of these two channels, their respective roles in signalling and also raise the question of the molecular identity of RMA. Finally, we propose functions for these two channels within the context of plant mechanotransduction.
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Affiliation(s)
- Yannick Guerringue
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France
| | - Sébastien Thomine
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France
| | - Jean-Marie Frachisse
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Sud, Université Paris-Saclay, Gif sur Yvette, France
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Wang Y, Cao G, Xu D, Fan L, Wu X, Ni X, Zhao S, Zheng P, Sun J, Ma Y. A Novel Corynebacterium glutamicum l-Glutamate Exporter. Appl Environ Microbiol 2018; 84:e02691-17. [PMID: 29330181 DOI: 10.1128/AEM.02691-17] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 01/07/2018] [Indexed: 01/24/2023] Open
Abstract
Besides metabolic pathways and regulatory networks, transport systems are also pivotal for cellular metabolism and hyperproduction of biochemicals using microbial cell factories. The identification and characterization of transporters are therefore of great significance for the understanding and engineering of transport reactions. Herein, a novel l-glutamate exporter, MscCG2, which exists extensively in Corynebacterium glutamicum strains but is distinct from the only known l-glutamate exporter, MscCG, was discovered in an industrial l-glutamate-producing C. glutamicum strain. MscCG2 was predicted to possess three transmembrane helices in the N-terminal region and located in the cytoplasmic membrane, which are typical structural characteristics of the mechanosensitive channel of small conductance. MscCG2 has a low amino acid sequence identity (23%) to MscCG and evolved separately from MscCG with four transmembrane helices. Despite the considerable differences between MscCG2 and MscCG in sequence and structure, gene deletion and complementation confirmed that MscCG2 also functioned as an l-glutamate exporter and an osmotic safety valve in C. glutamicum Besides, transcriptional analysis showed that MscCG2 and MscCG genes were transcribed in similar patterns and not induced by l-glutamate-producing conditions. It was also demonstrated that MscCG2-mediated l-glutamate excretion was activated by biotin limitation or penicillin treatment and that constitutive l-glutamate excretion was triggered by a gain-of-function mutation of MscCG2 (A151V). Discovery of MscCG2 will enrich the understanding of bacterial amino acid transport and provide additional targets for exporter engineering.IMPORTANCE The exchange of matter, energy, and information with surroundings is fundamental for cellular metabolism. Therefore, studying transport systems that are essential for these processes is of great significance. Besides, transport systems of bacterial cells are usually related to product excretion as well as product reuptake, making transporter engineering a useful strategy for strain improvement. The significance of our research is in identifying and characterizing a novel l-glutamate exporter from the industrial workhorse Corynebacterium glutamicum, which will enrich the understanding of l-glutamate excretion and provide a new target for studying bacterial amino acid transport and engineering transport reactions.
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Williamson DR, Dewan KK, Patel T, Wastella CM, Ning G, Kirimanjeswara GS. A Single Mechanosensitive Channel Protects Francisella tularensis subsp. holarctica from Hypoosmotic Shock and Promotes Survival in the Aquatic Environment. Appl Environ Microbiol 2018; 84:e02203-17. [PMID: 29269496 DOI: 10.1128/AEM.02203-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.IMPORTANCE The contamination of freshwater by Francisella tularensis subsp. holarctica has resulted in a number of outbreaks of tularemia. Invariably, the contamination originates from the carcasses or excreta of infected animals and thus involves an abrupt osmotic downshock as the bacteria enter freshwater. How F. tularensis survives this drastic change in osmolarity has not been clear, but here we report that a single mechanosensitive channel protects the bacterium from osmotic downshock. This channel is functional despite lacking much of the cytoplasmic vestibule domain that is present in better-studied organisms such as Escherichia coli; this report builds on previous studies that have suggested that parts of this domain are dispensable for downshock protection. These findings extend our understanding of the aquatic cycle and ecological persistence of F. tularensis, with further implications for mechanosensitive channel biology.
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Zhao Q, Wu K, Chi S, Geng J, Xiao B. Heterologous Expression of the Piezo1-ASIC1 Chimera Induces Mechanosensitive Currents with Properties Distinct from Piezo1. Neuron 2017; 94:274-277. [PMID: 28426963 DOI: 10.1016/j.neuron.2017.03.040] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 01/22/2017] [Accepted: 03/27/2017] [Indexed: 01/30/2023]
Abstract
Piezo1 represents a prototype of the mammalian mechanosensitive cation channel, but its molecular mechanism remains elusive. In a recent study, we showed that C-terminal region, which contains the last two TMs, of 2189-2547 of Piezo1 forms the bona fide pore module, and systematically identified the pore-lining helix and key pore-property-determining residues (Zhao et al., 2016). Furthermore, we have engineered the Piezo1(1-2190)-ASIC1 chimera (fusing the N-terminal region of 1-2190 to the mechano-insensitive ASIC1) that mediated mechanical- and acid-evoked currents in HEK293T cells, indicating the sufficiency of the N-terminal region in mechanotransduction. Now in a Matters Arising, the authors specifically questioned the implication of the chimera data among the many findings shown in our paper. They replicated the chimera-mediated mechanosensitive currents in HEK293T cells that have nearly no detectable expression of endogenous Piezo1, but paradoxically found the chimera to be less effective in Piezo1 knockout HEK293T cells, indicating the involvement of endogenous Piezo1. In this Matters Arising Response, we discuss the chimera results and consider potential interpretations in light of the Matters Arising from Dubin et al. (2017), published concurrently in this issue of Neuron. Please see also the response from Hong et al. (2017), published in this issue.
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Affiliation(s)
- Qiancheng Zhao
- School of Pharmaceutical Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Kun Wu
- School of Pharmaceutical Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Shaopeng Chi
- School of Pharmaceutical Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Jie Geng
- School of Pharmaceutical Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China
| | - Bailong Xiao
- School of Pharmaceutical Sciences, Tsinghua-Peking Joint Center for Life Sciences, IDG/McGovern Institute for Brain Research, Tsinghua University, Beijing 100084, China.
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Hong GS, Lee B, Oh U. Evidence for Mechanosensitive Channel Activity of Tentonin 3/TMEM150C. Neuron 2017; 94:271-273.e2. [PMID: 28426962 DOI: 10.1016/j.neuron.2017.03.038] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 03/06/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
Mechanosensation is essential for various physiological processes, and it is mediated by mechanotransduction channels. Recently, we reported that TMEM150C/Tentonin 3 (TTN3) confers mechanically activated currents with slow inactivation kinetics in several cell types, including dorsal root ganglion neurons (Hong et al., 2016). The accompanying Matters Arising by Dubin, Murthy, and colleagues confirms that naive heterologous cells demonstrate a mechanically activated current, but finds that this response is absent in CRISPR-Cas9 Piezo1 knockout cell lines and suggests that TTN3 is a modulator of Piezo1. We present and discuss evidence based on co-expression of TTN3 and Peizo1 and mutant variants of the pore region of TTN3 to support that TTN3 is a pore-forming unit, not an amplifying adaptor for Piezo1 activity. This Matters Arising Response paper, along with Zhao et al. (2017), addresses the Matters Arising from Dubin et al. (2017), published concurrently in this issue of Neuron.
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Affiliation(s)
- Gyu-Sang Hong
- Sensory Research Center, CRI, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Byeongjun Lee
- Sensory Research Center, CRI, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea
| | - Uhtaek Oh
- Sensory Research Center, CRI, Brain Science Institute, Korea Institute of Science and Technology, Seoul 02792, Korea; College of Pharmacy, Seoul National University, Seoul 08826, Korea.
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Bavi N, Bavi O, Vossoughi M, Naghdabadi R, Hill AP, Martinac B, Jamali Y. Nanomechanical properties of MscL α helices: A steered molecular dynamics study. Channels (Austin) 2016; 11:209-223. [PMID: 27753526 DOI: 10.1080/19336950.2016.1249077] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Gating of mechanosensitive (MS) channels is driven by a hierarchical cascade of movements and deformations of transmembrane helices in response to bilayer tension. Determining the intrinsic mechanical properties of the individual transmembrane helices is therefore central to understanding the intricacies of the gating mechanism of MS channels. We used a constant-force steered molecular dynamics (SMD) approach to perform unidirectional pulling tests on all the helices of MscL in M. tuberculosis and E. coli homologs. Using this method, we could overcome the issues encountered with the commonly used constant-velocity SMD simulations, such as low mechanical stability of the helix during stretching and high dependency of the elastic properties on the pulling rate. We estimated Young's moduli of the α-helices of MscL to vary between 0.2 and 12.5 GPa with TM2 helix being the stiffest. We also studied the effect of water on the properties of the pore-lining TM1 helix. In the absence of water, this helix exhibited a much stiffer response. By monitoring the number of hydrogen bonds, it appears that water acts like a 'lubricant' (softener) during TM1 helix elongation. These data shed light on another physical aspect underlying hydrophobic gating of MS channels, in particular MscL.
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Affiliation(s)
- N Bavi
- a Division of Molecular Cardiology and Biophysics , Victor Chang Cardiac Research Institute , Darlinghurst , NSW , Australia.,b St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Darlinghurst , NSW , Australia
| | - O Bavi
- c Institute for Nanoscience and Nanotechnology, Sharif University of Technology , Tehran , Iran
| | - M Vossoughi
- c Institute for Nanoscience and Nanotechnology, Sharif University of Technology , Tehran , Iran.,d Biochemical & Bioenvironmental Research Center (BBRC) , Tehran , Iran
| | - R Naghdabadi
- c Institute for Nanoscience and Nanotechnology, Sharif University of Technology , Tehran , Iran.,e Department of Mechanical Engineering , Sharif University of Technology , Tehran , Iran
| | - A P Hill
- a Division of Molecular Cardiology and Biophysics , Victor Chang Cardiac Research Institute , Darlinghurst , NSW , Australia
| | - B Martinac
- a Division of Molecular Cardiology and Biophysics , Victor Chang Cardiac Research Institute , Darlinghurst , NSW , Australia.,b St Vincent's Clinical School, Faculty of Medicine , University of New South Wales , Darlinghurst , NSW , Australia
| | - Y Jamali
- f Department of Mathematics , Tarbiat Modares University , Tehran , Iran.,g Computational Physical Sciences Research Laboratory , School of Nanoscience, Institute for Research in Fundamental Sciences (IPM) , Tehran , Iran
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Li J, Guo J, Ou X, Zhang M, Li Y, Liu Z. Mechanical coupling of the multiple structural elements of the large-conductance mechanosensitive channel during expansion. Proc Natl Acad Sci U S A 2015; 112:10726-31. [PMID: 26261325 DOI: 10.1073/pnas.1503202112] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The prokaryotic mechanosensitive channel of large conductance (MscL) is a pressure-relief valve protecting the cell from lysing during acute osmotic downshock. When the membrane is stretched, MscL responds to the increase of membrane tension and opens a nonselective pore to about 30 Å wide, exhibiting a large unitary conductance of ∼ 3 nS. A fundamental step toward understanding the gating mechanism of MscL is to decipher the molecular details of the conformational changes accompanying channel opening. By applying fusion-protein strategy and controlling detergent composition, we have solved the structures of an archaeal MscL homolog from Methanosarcina acetivorans trapped in the closed and expanded intermediate states. The comparative analysis of these two new structures reveals significant conformational rearrangements in the different domains of MscL. The large changes observed in the tilt angles of the two transmembrane helices (TM1 and TM2) fit well with the helix-pivoting model derived from the earlier geometric analyses based on the previous structures. Meanwhile, the periplasmic loop region transforms from a folded structure, containing an ω-shaped loop and a short β-hairpin, to an extended and partly disordered conformation during channel expansion. Moreover, a significant rotating and sliding of the N-terminal helix (N-helix) is coupled to the tilting movements of TM1 and TM2. The dynamic relationships between the N-helix and TM1/TM2 suggest that the N-helix serves as a membrane-anchored stopper that limits the tilts of TM1 and TM2 in the gating process. These results provide direct mechanistic insights into the highly coordinated movement of the different domains of the MscL channel when it expands.
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Rowe I, Guo M, Yasmann A, Cember A, Sintim HO, Sukharev S. Membrane Affinity of Platensimycin and Its Dialkylamine Analogs. Int J Mol Sci 2015; 16:17909-32. [PMID: 26247942 DOI: 10.3390/ijms160817909] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 12/13/2022] Open
Abstract
Membrane permeability is a desired property in drug design, but there have been difficulties in quantifying the direct drug partitioning into native membranes. Platensimycin (PL) is a new promising antibiotic whose biosynthetic production is costly. Six dialkylamine analogs of PL were synthesized with identical pharmacophores but different side chains; five of them were found inactive. To address the possibility that their activity is limited by the permeation step, we calculated polarity, measured surface activity and the ability to insert into the phospholipid monolayers. The partitioning of PL and the analogs into the cytoplasmic membrane of E. coli was assessed by activation curve shifts of a re-engineered mechanosensitive channel, MscS, in patch-clamp experiments. Despite predicted differences in polarity, the affinities to lipid monolayers and native membranes were comparable for most of the analogs. For PL and the di-myrtenyl analog QD-11, both carrying bulky sidechains, the affinity for the native membrane was lower than for monolayers (half-membranes), signifying that intercalation must overcome the lateral pressure of the bilayer. We conclude that the biological activity among the studied PL analogs is unlikely to be limited by their membrane permeability. We also discuss the capacity of endogenous tension-activated channels to detect asymmetric partitioning of exogenous substances into the native bacterial membrane and the different contributions to the thermodynamic force which drives permeation.
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Lansman JB. Utrophin suppresses low frequency oscillations and coupled gating of mechanosensitive ion channels in dystrophic skeletal muscle. Channels (Austin) 2015; 9:145-60. [PMID: 25941878 DOI: 10.1080/19336950.2015.1040211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
An absence of utrophin in muscle from mdx mice prolongs the open time of single mechanosensitive channels. On a time scale much longer than the duration of individual channel activations, genetic depletion of utrophin produces low frequency oscillations of channel open probability. Oscillatory channel opening occurred in the dystrophin/utrophin mutants, but was absent in wild-type and mdx fibers. By contrast, small conductance channels showed random gating behavior when present in the same patch. Applying a negative pressure to a patch on a DKO fiber produced a burst of mode II activity, but channels subsequently closed and remained silent for tens of seconds during the maintained pressure stimulus. In addition, simultaneous opening of multiple MS channels could be frequently observed in recordings from patches on DKO fibers, but only rarely in wild-type and mdx muscle. A model which accounts for the single-channel data is proposed in which utrophin acts as gating spring which maintains the mechanical stability a caveolar-like compartment. The state of this compartment is suggested to be dynamic; its continuity with the extracellular surface varying over seconds to minutes. Loss of the mechanical stability of this compartment contributes to pathogenic Ca(2+) entry through MS channels in Duchenne dystrophy.
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Affiliation(s)
- Jeffry B Lansman
- a Department of Cellular and Molecular Pharmacology ; School of Medicine; University of California San Francisco; San Francisco , CA USA
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Meng Q, Fang P, Hu Z, Ling Y, Liu H. Mechanotransduction of trigeminal ganglion neurons innervating inner walls of rat anterior eye chambers. Am J Physiol Cell Physiol 2015; 309:C1-10. [PMID: 25904679 DOI: 10.1152/ajpcell.00028.2015] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
Abstract
To address mechanoreceptive roles of trigeminal ganglion (TG) nerve endings in the inner walls of rat anterior eye chambers, we investigated the mechanotransduction process and mechanosensitive (MS) channel on somata of TG neurons innervating this area in vitro. Rat TG neurons innervating inner walls of anterior chambers were labeled by anterior chamber injection of 1,1'-dilinoleyl-3,3,3',3'-tetramethylindocarbocyanine, 4-chlorobenzenesulfonate (FAST DiI). The neuronal cell bodies were voltage clamped using a whole cell patch-clamp technique, while it was deformed by ejection of bath solution to verify mechanotransduction. Immunofluorescence staining was performed on sections of TG ganglia to determine the specific MS channel proteins. Mechanical stimuli induced MS currents in 55 out of 96 FAST DiI-labeled TG neurons. The MS currents exhibited mechanical intensity-dependent and clamp voltage-dependent characteristics. Mechanical stimulation further enhanced the membrane potential and increased the frequency of action potentials. Transient receptor potential ankyrin 1 (TRPA1), TRP vanilloid 4 (TRPV4), acid-sensing ion channel (ASIC) 2 and ASIC3 channel proteins were expressed in FAST DiI-labeled TG neurons. The inhibitory effect of HC-030031, a specific inhibitor of TRPA1, on MS currents demonstrated that TRPA1 was an essential MS channel protein. Taken together, our results show that mechanical stimuli induce MS currents via MS channels such as TRPA1 to trigger mechanotransduction in TG neurons innervating inner walls of anterior chambers. Our results indicate the existence of mechanoreceptive TG nerve endings in inner walls of anterior chambers. Whether the mechanoreceptive TG nerve endings play a role in intraocular pressure sensation warrants further investigation.
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Affiliation(s)
- Qingli Meng
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
| | - Peng Fang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China
| | - Zhuangli Hu
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China
| | - Yun Ling
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
| | - Haixia Liu
- Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Hubei, China; and
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Ando C, Liu N, Yoshimura K. A cytoplasmic helix is required for pentamer formation of the Escherichia coli MscL mechanosensitive channel. J Biochem 2015; 158:109-14. [PMID: 25697390 DOI: 10.1093/jb/mvv019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 01/14/2015] [Indexed: 01/01/2023] Open
Abstract
Many membrane proteins such as ion channels are oligomers, but the determinants of the degree of oligomerization are not fully understood. Mechanosensitive channel with large conductance (MscL), which is ubiquitous in bacteria, is a homopentamer with two transmembrane helices and a cytoplasmic helix in each subunit. The carboxyl-terminal cytoplasmic helices assemble into a pentameric bundle that resembles cartilage oligomeric matrix protein. To address the role of cytoplasmic helices in the pentamer formation of Escherichia coli MscL, we generated MscL constructs with various deletions at the carboxyl terminus and translated them in a cell-free system. Deletions of Leu-129 and the downstream sequence resulted in formation of various oligomers without preference to pentamers, suggesting that nearly the whole cytoplasmic helix is required for MscL pentamer formation.
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Affiliation(s)
- Chie Ando
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan
| | - Naili Liu
- Department of Biology, University of Maryland, 1210 Biology-Psychology Bldg., College Park, MD 20742, USA; and
| | - Kenjiro Yoshimura
- Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572, Japan; Department of Biology, University of Maryland, 1210 Biology-Psychology Bldg., College Park, MD 20742, USA; and Department of Machinery and Control Systems, Shibaura Institute of Technology, 307 Fukasaku, Minuma-ku, Saitama-shi, Saitama 337-8570, Japan
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Abstract
The effect of focal mechanical stress on the localization of TRPV2 was investigated in HT1080 cells, where only mRNA for TRPV2 was detected among members of the TRPV channel family. Mechanical stress was applied by adding negative pressure using a glass pipette. When focal mechanical stress was applied, subplasma membrane Ca2+ concentration ([Ca2+]s) was increased beneath the pipette, which propagated throughout the cell. The increase in [Ca2+]s was blocked by ruthenium red or by knocking down TRPV2. Elevation of [Ca2+]s was not observed by removal of extracellular Ca2+, by an addition of a phosphatidylinositol 3-kinase inhibitor LY29034, and by transfection of dominant-negative Rac. In cells expressing GFP-TRPV2 and RFP-Akt, administration of focal mechanical stress induced accumulation of GFP-TRPV2 beneath the pipette. RFP-Akt was also accumulated to the same site. Gadolinium blocked the elevation of [Ca2+]s induced by focal mechanical stress and also attenuated accumulation of TRPV2. When GFP-TRPV1, GFP-TRPV3, GFP-TRPV4, GFP-TRPV5, or GFP-TRPV6 was transfected ectopically in HT1080 cells, only GFP-TRPV4 was accumulated beneath the pipette in response to the focal mechanical stress. These results indicate that TRPV2 translocates to the site receiving a focal mechanical stress and increases [Ca2+]s.
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Affiliation(s)
- Masahiro Nagasawa
- Institute for Molecular & Cellular Regulation, Gunma University, Maebashi, Japan
| | - Itaru Kojima
- Institute for Molecular & Cellular Regulation, Gunma University, Maebashi, Japan
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Retraction: Mechanosensitive channel candidate MCA2 is involved in touch-induced root responses in Arabidopsis. Front Plant Sci 2015; 6:153. [PMID: 25798143 PMCID: PMC4350080 DOI: 10.3389/fpls.2015.00153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 02/26/2015] [Indexed: 05/10/2023]
Abstract
[This retracts the article on p. 421 in vol. 5, PMID: 25191336.].
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Nakano M, Samejima R, Iida H. Mechanosensitive channel candidate MCA2 is involved in touch-induced root responses in Arabidopsis. Front Plant Sci 2014; 5:421. [PMID: 25191336 PMCID: PMC4140169 DOI: 10.3389/fpls.2014.00421] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 08/06/2014] [Indexed: 05/26/2023]
Abstract
The Ca(2+)-permeable mechanosensitive (MS) channel is a mechanical stress sensor. We previously reported that Arabidopsis MCA1 and its paralog MCA2 functioned individually as Ca(2+)-permeable MS channels. In the present study, we showed that the primary roots of the mca2-null mutant behaved abnormally on the surface of hard medium. First, primary roots are known to exhibit a skewing growth pattern on the surface of vertically placed agar medium. On such surface, the primary roots of mca2-null skewed more than those of the wild type. Second, when seedlings were grown on a tilted agar surface, the primary root of mca2-null showed abnormal waving patterns. Third, wild-type seedlings eventually died when grown on horizontally placed 3.2% gelrite medium, which was too hard to allow the primary roots of the wild type to penetrate, because their primary roots sprang from the surface of the medium and may have been unable to absorb water and nutrients. In contrast, the primary roots of mca2-null, but not those of mca1-null, were able to creep over the surface of the medium and grow. Fourth, when grown on the surface of 3.2% agar medium supplemented with 30 mM CaCl2, only mca2-null grew with a root that coiled in a clockwise direction. Lastly, on the surface of vertically placed rectangular plates that allowed primary roots to grow vertically down to the frame of the plate, wild-type primary roots grew horizontally after touching the frame at an angle of 90(∘). During the horizontal growth, only the extreme root tips maintained contact with the frame. In contrast, the primary roots of mca2-null allowed not only the extreme root tips, but also the meristem and elongation zones to maintain contact with the frame during horizontal growth. These results suggest that MCA2 is involved in touch-related root responses.
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Affiliation(s)
| | | | - Hidetoshi Iida
- *Correspondence: Hidetoshi Iida, Department of Biology, Tokyo Gakugei University, 4-1-1 Kukui kita-machi, Koganei-shi, Tokyo 184-8501, Japan e-mail:
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Nakayama Y, Hirata A, Iida H. Mechanosensitive channels Msy1 and Msy2 are required for maintaining organelle integrity upon hypoosmotic shock in Schizosaccharomyces pombe. FEMS Yeast Res 2014; 14:992-4. [PMID: 25041276 DOI: 10.1111/1567-1364.12181] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 06/30/2014] [Accepted: 07/03/2014] [Indexed: 11/29/2022] Open
Abstract
The mechanosensitive channels, Mys1 and Msy2, in fission yeast are localized in the endoplasmic reticulum membrane and control cytoplasmic Ca(2+) levels in the hypoosmotic response. We here investigated changes in organellar structures with hypoosmotic shock using transmission electron microscopy. While msy1(-) and msy2(-) single mutant cells developed a number of swollen vacuoles following hypoosmotic shock, similar to wild-type cells, msy1(-) msy2(-) double mutant cells only had two abnormally large vacuoles and cracks between the inner and outer nuclear membranes. These results suggest that Msy1 and Msy2 may be involved in maintaining vacuole integrity and protecting the nuclear envelope upon hypoosmotic shock and also that these two channels are functionally complementary.
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Affiliation(s)
- Yoshitaka Nakayama
- Department of Biology, Tokyo Gakugei University, Koganei-shi, Tokyo, Japan
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46
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Song S, Yamamura A, Yamamura H, Ayon RJ, Smith KA, Tang H, Makino A, Yuan JXJ. Flow shear stress enhances intracellular Ca2+ signaling in pulmonary artery smooth muscle cells from patients with pulmonary arterial hypertension. Am J Physiol Cell Physiol 2014; 307:C373-83. [PMID: 24920677 DOI: 10.1152/ajpcell.00115.2014] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
An increase in cytosolic Ca(2+) concentration ([Ca(2+)]cyt) in pulmonary arterial smooth muscle cells (PASMC) is a major trigger for pulmonary vasoconstriction and an important stimulus for pulmonary arterial medial hypertrophy in patients with idiopathic pulmonary arterial hypertension (IPAH). Vascular smooth muscle cells (SMC) sense the blood flow shear stress through interstitial fluid driven by pressure or direct exposure to blood flow in case of endothelial injury. Mechanical stimulus can increase [Ca(2+)]cyt. Here we report that flow shear stress raised [Ca(2+)]cyt in PASMC, while the shear stress-mediated rise in [Ca(2+)]cyt and the protein expression level of TRPM7 and TRPV4 channels were significantly greater in IPAH-PASMC than in normal PASMC. Blockade of TRPM7 by 2-APB or TRPV4 by Ruthenium red inhibited shear stress-induced rise in [Ca(2+)]cyt in normal and IPAH-PASMC, while activation of TRPM7 by bradykinin or TRPV4 by 4αPDD induced greater increase in [Ca(2+)]cyt in IPAH-PASMC than in normal PASMC. The bradykinin-mediated activation of TRPM7 also led to a greater increase in [Mg(2+)]cyt in IPAH-PASMC than in normal PASMC. Knockdown of TRPM7 and TRPV4 by siRNA significantly attenuated the shear stress-mediated [Ca(2+)]cyt increases in normal and IPAH-PASMC. In conclusion, upregulated mechanosensitive channels (e.g., TRPM7, TRPV4, TRPC6) contribute to the enhanced [Ca(2+)]cyt increase induced by shear stress in PASMC from IPAH patients. Blockade of the mechanosensitive cation channels may represent a novel therapeutic approach for relieving elevated [Ca(2+)]cyt in PASMC and thereby inhibiting sustained pulmonary vasoconstriction and pulmonary vascular remodeling in patients with IPAH.
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Affiliation(s)
- Shanshan Song
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Departments of Medicine and Physiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Aya Yamamura
- Kinjo Gakuin University School of Pharmacy, Nagoya, Japan; and
| | - Hisao Yamamura
- Nagoya City University Graduate School of Pharmaceutical Sciences, Nagoya, Japan
| | - Ramon J Ayon
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Departments of Medicine and Physiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Kimberly A Smith
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Haiyang Tang
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Departments of Medicine and Physiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Ayako Makino
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Departments of Medicine and Physiology, University of Arizona College of Medicine, Tucson, Arizona
| | - Jason X-J Yuan
- Department of Medicine, University of Illinois at Chicago, Chicago, Illinois; Departments of Medicine and Physiology, University of Arizona College of Medicine, Tucson, Arizona;
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47
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Tatsumi H, Furuichi T, Nakano M, Toyota M, Hayakawa K, Sokabe M, Iida H. Mechanosensitive channels are activated by stress in the actin stress fibres, and could be involved in gravity sensing in plants. Plant Biol (Stuttg) 2014; 16 Suppl 1:18-22. [PMID: 24016318 DOI: 10.1111/plb.12095] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 07/18/2013] [Indexed: 05/14/2023]
Abstract
Mechanosensitive (MS) channels are expressed in a variety of cells. The molecular and biophysical mechanism involved in the regulation of MS channel activities is a central interest in basic biology. MS channels are thought to play crucial roles in gravity sensing in plant cells. To date, two mechanisms have been proposed for MS channel activation. One is that tension development in the lipid bilayer directly activates MS channels. The second mechanism proposes that the cytoskeleton is involved in the channel activation, because MS channel activities are modulated by pharmacological treatments that affect the cytoskeleton. We tested whether tension in the cytoskeleton activates MS channels. Mammalian endothelial cells were microinjected with phalloidin-conjugated beads, which bound to stress fibres, and a traction force to the actin cytoskeleton was applied by dragging the beads with optical tweezers. MS channels were activated when the force was applied, demonstrating that a sub-pN force to the actin filaments activates a single MS channel. Plants may use a similar molecular mechanism in gravity sensing, since the cytoplasmic Ca(2+) concentration increase induced by changes in the gravity vector was attenuated by potential MS channel inhibitors, and by actin-disrupting drugs. These results support the idea that the tension increase in actin filaments by gravity-dependent sedimentation of amyloplasts activates MS Ca(2+) -permeable channels, which can be the molecular mechanism of a Ca(2+) concentration increase through gravistimulation. We review recent progress in the study of tension sensing by actin filaments and MS channels using advanced biophysical methods, and discuss their possible roles in gravisensing.
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Affiliation(s)
- H Tatsumi
- Nagoya University Graduate School of Medicine, Nagoya, Japan
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48
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Tatsumi H, Toyota M, Furuichi T, Sokabe M. Calcium mobilizations in response to changes in the gravity vector in Arabidopsis seedlings: possible cellular mechanisms. Plant Signal Behav 2014; 9:e29099. [PMID: 25763612 PMCID: PMC4203510 DOI: 10.4161/psb.29099] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2014] [Revised: 05/02/2014] [Accepted: 05/02/2014] [Indexed: 05/11/2023]
Abstract
Gravity influences the growth direction of higher plants. Changes in the gravity vector (gravistimulation) immediately promote the increase in the cytoplasmic free calcium ion concentration ([Ca(2+)]c) in Arabidopsis (Arabidopsis thaliana) seedlings. When the seedlings are gravistimulated by reorientation at 180°, a transient two peaked (biphasic) [Ca(2+)]c-increase arises in their hypocotyl and petioles. Parabolic flights (PFs) can generate a variety of gravity-stimuli, and enables us to measure gravity-induced [Ca(2+)]c-increases without specimen rotation, which demonstrate that Arabidopsis seedlings possess a rapid gravity-sensing mechanism linearly transducing a wide range of gravitational changes into Ca(2+) signals on a sub-second timescale. Hypergravity by centrifugation (20 g or 300 g) also induces similar transient [Ca(2+)]c-increases. In this review, we propose models for possible cellular processes of the garavi-stimulus-induced [Ca(2+)]c-increase, and evaluate those by examining whether the model fits well with the kinetic parameters derived from the [Ca(2+)]c-increases obtained by applying gravistimulus with different amplitudes and time sequences.
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Affiliation(s)
- Hitoshi Tatsumi
- Nagoya University Graduate School of Medicine; Nagoya, Japan
| | - Masatsugu Toyota
- Department of Botany; University of Wisconsin; Madison, WI USA
- Precursory Research for Embryonic Science and Technology (PRESTO); Japan Science and Technology Agency (JST); Kawaguchi, Saitama, Japan
| | - Takuya Furuichi
- Department of Health and Nutrition; Gifu Women’s University; Gifu, Japan
| | - Masahiro Sokabe
- Nagoya University Graduate School of Medicine; Nagoya, Japan
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49
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Nanatani K, Shijuku T, Akai M, Yukutake Y, Yasui M, Hamamoto S, Onai K, Morishita M, Ishiura M, Uozumi N. Characterization of the role of a mechanosensitive channel in osmotic down shock adaptation in Synechocystis sp PCC 6803. Channels (Austin) 2013; 7:238-42. [PMID: 23764907 DOI: 10.4161/chan.25350] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Synechocystis sp strain PCC 6803 contains one gene encoding a putative large conductance mechanosensitive channel homolog [named SyMscL (slr0875)]. However, it is unclear whether SyMscL contributes to the adaptation to hypoosmotic stress in Synechocystis. Here we report the in vivo characteristics of SyMscL. SyMscL was mainly expressed in the plasma membrane of Synechocystis. Cell volume monitoring using stopped-flow spectrophotometry showed that ΔsymscL cells swelled more rapidly than wild-type cells under hypoosmotic stress conditions. Expression of symscL was under circadian control, and its peak corresponded to the beginning of subjective night. These results indicate that SyMscL functioned as one component of the osmotic homeostatic regulatory system of the cell coordinating the response of Synechocystis to daily metabolic osmotic fluctuations and environmental changes.
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Affiliation(s)
- Kei Nanatani
- Department of Biomolecular Engineering; Graduate School of Engineering; Tohoku University; Sendai, Japan
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50
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Abstract
In bacteria, MscS-type mechanosensitive channels serve to protect cells from lysis as they swell during extreme osmotic stress. We recently showed that two MscS homologs from Arabidopsis thaliana serve a similar purpose in the epidermal plastids of the leaf, indicating that the plant cell cytoplasm can present a dynamic osmotic challenge to the plastid. MscS homologs are predicted to be targeted to both plastids and mitochondrial envelopes and have been found in the genomes of intracellular pathogens. Here we discuss the implications of these observations, and propose that MS channels provide an essential mechanism for osmotic adaptation to both intracellular and the extracellular environments.
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