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Gong R, Qin L, Chen L, Wang N, Bao Y, Lu W. Myosin Va-dependent Transport of NMDA Receptors in Hippocampal Neurons. Neurosci Bull 2024; 40:1053-1075. [PMID: 38291290 PMCID: PMC11306496 DOI: 10.1007/s12264-023-01174-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Accepted: 11/03/2023] [Indexed: 02/01/2024] Open
Abstract
N-methyl-D-aspartate receptor (NMDAR) trafficking is a key process in the regulation of synaptic efficacy and brain function. However, the molecular mechanism underlying the surface transport of NMDARs is largely unknown. Here we identified myosin Va (MyoVa) as the specific motor protein that traffics NMDARs in hippocampal neurons. We found that MyoVa associates with NMDARs through its cargo binding domain. This association was increased during NMDAR surface transport. Knockdown of MyoVa suppressed NMDAR transport. We further demonstrated that Ca2+/calmodulin-dependent protein kinase II (CaMKII) regulates NMDAR transport through its direct interaction with MyoVa. Furthermore, MyoVa employed Rab11 family-interacting protein 3 (Rab11/FIP3) as the adaptor proteins to couple themselves with NMDARs during their transport. Accordingly, the knockdown of FIP3 impairs hippocampal memory. Together, we conclude that in hippocampal neurons, MyoVa conducts active transport of NMDARs in a CaMKII-dependent manner.
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Affiliation(s)
- Ru Gong
- Ministry of Education (MOE) Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Linwei Qin
- Ministry of Education (MOE) Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Linlin Chen
- Department of Neurobiology, Nanjing Medical University, Nanjing, 210096, China
| | - Ning Wang
- Department of Neurobiology, Nanjing Medical University, Nanjing, 210096, China
| | - Yifei Bao
- Ministry of Education (MOE) Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China
| | - Wei Lu
- Ministry of Education (MOE) Key Laboratory of Developmental Genes and Human Disease, School of Life Science and Technology, Southeast University, Nanjing, 210096, China.
- Department of Neurosurgery, State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Huashan Hospital, Institute for Translational Brain Research, Fudan University, Shanghai, 200032, China.
- Department of Neurobiology, Nanjing Medical University, Nanjing, 210096, China.
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226001, China.
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2
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Konietzny A, Grendel J, Kadek A, Bucher M, Han Y, Hertrich N, Dekkers DHW, Demmers JAA, Grünewald K, Uetrecht C, Mikhaylova M. Caldendrin and myosin V regulate synaptic spine apparatus localization via ER stabilization in dendritic spines. EMBO J 2022; 41:e106523. [PMID: 34935159 PMCID: PMC8844991 DOI: 10.15252/embj.2020106523] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2020] [Revised: 11/08/2021] [Accepted: 11/19/2021] [Indexed: 11/21/2022] Open
Abstract
Excitatory synapses of principal hippocampal neurons are frequently located on dendritic spines. The dynamic strengthening or weakening of individual inputs results in structural and molecular diversity of dendritic spines. Active spines with large calcium ion (Ca2+ ) transients are frequently invaded by a single protrusion from the endoplasmic reticulum (ER), which is dynamically transported into spines via the actin-based motor myosin V. An increase in synaptic strength correlates with stable anchoring of the ER, followed by the formation of an organelle referred to as the spine apparatus. Here, we show that myosin V binds the Ca2+ sensor caldendrin, a brain-specific homolog of the well-known myosin V interactor calmodulin. While calmodulin is an essential activator of myosin V motor function, we found that caldendrin acts as an inhibitor of processive myosin V movement. In mouse and rat hippocampal neurons, caldendrin regulates spine apparatus localization to a subset of dendritic spines through a myosin V-dependent pathway. We propose that caldendrin transforms myosin into a stationary F-actin tether that enables the localization of ER tubules and formation of the spine apparatus in dendritic spines.
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Affiliation(s)
- Anja Konietzny
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Jasper Grendel
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Alan Kadek
- Leibniz Institute for Experimental Virology (HPI)HamburgGermany
- European XFEL GmbHSchenefeldGermany
| | - Michael Bucher
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | - Yuhao Han
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
| | - Nathalie Hertrich
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
| | | | | | - Kay Grünewald
- Leibniz Institute for Experimental Virology (HPI)HamburgGermany
- Centre for Structural Systems BiologyHamburgGermany
- Department of ChemistryUniversity of HamburgHamburgGermany
| | - Charlotte Uetrecht
- Leibniz Institute for Experimental Virology (HPI)HamburgGermany
- European XFEL GmbHSchenefeldGermany
- Centre for Structural Systems BiologyHamburgGermany
| | - Marina Mikhaylova
- RG OptobiologyInstitute of BiologyHumboldt Universität zu BerlinBerlinGermany
- Guest Group Neuronal Protein TransportCenter for Molecular NeurobiologyZMNHUniversity Medical Center Hamburg‐EppendorfHamburgGermany
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Cao L, Wang Z, Zhang D, Li X, Hou C, Ren C. Phosphorylation of myosin regulatory light chain at Ser17 regulates actomyosin dissociation. Food Chem 2021; 356:129655. [PMID: 33831832 DOI: 10.1016/j.foodchem.2021.129655] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 03/07/2021] [Accepted: 03/16/2021] [Indexed: 11/19/2022]
Abstract
Phosphorylation of myosin regulatory light chain (MRLC) can regulate muscle contraction and thus affect actomyosin dissociation and meat quality. The objective of this study was to explore the mechanism by how MRLC phosphorylation regulates actomyosin dissociation and thus develop strategies for improving meat quality. Here, the phosphorylation status of MRLC was modulated by myosin light chain kinase and myosin light chain kinase inhibitor. MRLC phosphorylation at Ser17 decreased the kinetic energy and total energy of actomyosin, thus stabilized the structure, facilitating the interaction between myosin and actin; this was one possible way that MRLC phosphorylation at Ser17 negatively affects actomyosin dissociation. Moreover, MRLC phosphorylation at Ser17 was beneficial to the formation of ionic bonds, hydrogen bonds, and hydrophobic interaction between myosin and actin, and was the second possible way that MRLC phosphorylation at Ser17 negatively affects actomyosin dissociation.
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Affiliation(s)
- Lichuang Cao
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China; Department of Food Science, Faculty of Science, University of Copenhagen, 1958 Frederiksberg C, Denmark.
| | - Zhenyu Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China.
| | - Dequan Zhang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China.
| | - Xin Li
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China
| | - Chengli Hou
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China
| | - Chi Ren
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Key Laboratory of Agro-Products Processing, Ministry of Agriculture and Rural Affairs, Beijing 100193, PR China
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4
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Canclini L, Cal K, Bardier C, Ruiz P, Mercer JA, Calliari A. Calcium triggers the dissociation of myosin-Va from ribosomes in ribonucleoprotein complexes. FEBS Lett 2020; 594:2311-2321. [PMID: 32412091 DOI: 10.1002/1873-3468.13813] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/29/2020] [Accepted: 04/30/2020] [Indexed: 11/08/2022]
Abstract
The sorting of RNAs to specific regions of the cell for local translation represents an important mechanism directing protein distribution and cell compartmentalization. While significant progress has been made in understanding the mechanisms underlying the transport and localization of mRNAs, the mechanisms governing ribosome mobilization are less well understood. Ribosomes present in the cytoplasm of multiple cell types can form ribonucleoprotein complexes that also contain myosin-Va (Myo5a), a processive, actin-dependent molecular motor. Here, we report that Myo5a can be disassociated from ribosomes when ribonucleoprotein complexes are exposed to calcium, both in vitro and in vivo. We suggest that Myo5a may act as a molecular switch able to anchor or release ribosomes from the actin cytoskeleton in response to intracellular signaling.
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Affiliation(s)
- Lucía Canclini
- Department of Genetics, Instituto de Investigaciones Biológicas 'Clemente Estable' (MEC), Montevideo, Uruguay
| | - Karina Cal
- Department of Biosciences, Facultad de Veterinaria, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Camila Bardier
- Department of Genetics, Instituto de Investigaciones Biológicas 'Clemente Estable' (MEC), Montevideo, Uruguay
| | - Paul Ruiz
- Department of Biosciences, Facultad de Veterinaria, Universidad de la República (UdelaR), Montevideo, Uruguay
| | | | - Aldo Calliari
- Department of Biosciences, Facultad de Veterinaria, Universidad de la República (UdelaR), Montevideo, Uruguay
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Ye Z, Ander BP, Sharp FR, Zhan X. Cleaved β-Actin May Contribute to DNA Fragmentation Following Very Brief Focal Cerebral Ischemia. J Neuropathol Exp Neurol 2019; 77:260-265. [PMID: 29408985 DOI: 10.1093/jnen/nly003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Our previous study demonstrated caspase independent DNA fragmentation after very brief cerebral ischemia, the mechanism of which was unclear. In this study, we explore whether actin is cleaved following focal cerebral ischemia, and whether these structural changes of actin might modulate DNA fragmentation observed following focal ischemia. Results showed that a cleaved β-actin fragment was identified in brains of rats 24 hours following 10-minute and 2-hour focal ischemia. Though granzyme B and caspase-3 cleaved β-actin in vitro, the fragment size of β-actin cleaved by granzyme B was the same as those found after 10-minute and 2-hour focal ischemia. This was consistent with increases of granzyme B activity after 10-minute and 2-hour ischemia compared with controls. Cerebral extracts from 10-minute and 2-hour ischemic brains degraded DNA in vitro. Adding intact β-actin to these samples completely abolished DNA degradation from the 10-minute ischemia group but not from the 2-hour ischemia group. We concluded that β-actin is likely cleaved by granzyme B by 24 hours following 10-minute and 2-hour focal cerebral ischemia. Intact β-actin inhibits DNase, and cleavage of β-actin activates DNase, which leads to DNA fragmentation observed in the brain following very brief focal ischemia.
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Affiliation(s)
- Zhouheng Ye
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, California.,Department of Aerospace and Diving, Nautical and Aviation Medical Center, Navy General Hospital, Beijing, China
| | - Bradley P Ander
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, California
| | - Frank R Sharp
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, California
| | - Xinhua Zhan
- Department of Neurology, MIND Institute, University of California at Davis, Sacramento, California
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6
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Zhang N, Yao LL, Li XD. Regulation of class V myosin. Cell Mol Life Sci 2018; 75:261-273. [PMID: 28730277 PMCID: PMC11105390 DOI: 10.1007/s00018-017-2599-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 06/27/2017] [Accepted: 07/17/2017] [Indexed: 01/26/2023]
Abstract
Class V myosin (myosin-5) is a molecular motor that functions as an organelle transporter. The activation of myosin-5's motor function has long been known to be associated with a transition from the folded conformation in the off-state to the extended conformation in the on-state, but only recently have we begun to understand the underlying mechanism. The globular tail domain (GTD) of myosin-5 has been identified as the inhibitory domain and has recently been shown to function as a dimer in regulating the motor function. The folded off-state of myosin-5 is stabilized by multiple intramolecular interactions, including head-GTD interactions, GTD-GTD interactions, and interactions between the GTD and the C-terminus of the first coiled-coil segment. Any cellular factor that affects these intramolecular interactions and thus the stability of the folded conformation of myosin-5 would be expected to regulate myosin-5 motor function. Both the adaptor proteins of myosin-5 and Ca2+ are potential regulators of myosin-5 motor function, because they can destabilize its folded conformation. A combination of these regulators provides a versatile scheme in regulating myosin-5 motor function in the cell.
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Affiliation(s)
- Ning Zhang
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Lin-Lin Yao
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiang-Dong Li
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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7
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Fert-Bober J, Giles JT, Holewinski RJ, Kirk JA, Uhrigshardt H, Crowgey EL, Andrade F, Bingham CO, Park JK, Halushka MK, Kass DA, Bathon JM, Van Eyk JE. Citrullination of myofilament proteins in heart failure. Cardiovasc Res 2015; 108:232-42. [PMID: 26113265 PMCID: PMC4614685 DOI: 10.1093/cvr/cvv185] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 06/12/2015] [Accepted: 06/17/2015] [Indexed: 11/12/2022] Open
Abstract
AIMS Citrullination, the post-translational conversion of arginine to citrulline by the enzyme family of peptidylarginine deiminases (PADs), is associated with several diseases, and specific citrullinated proteins have been shown to alter function while others act as auto-antigens. In this study, we identified citrullinated proteins in human myocardial samples, from healthy and heart failure patients, and determined several potential functional consequences. Further we investigated PAD isoform cell-specific expression in the heart. METHODS AND RESULTS A citrullination-targeted proteomic strategy using data-independent (SWATH) acquisition method was used to identify the modified cardiac proteins. Citrullinated-induced sarcomeric proteins were validated using two-dimensional gel electrophoresis and investigated using biochemical and functional assays. Myocardial PAD isoforms were confirmed by RT-PCR with PAD2 being the major isoform in myocytes. In total, 304 citrullinated sites were identified that map to 145 proteins among the three study groups: normal, ischaemia, and dilated cardiomyopathy. Citrullination of myosin (using HMM fragment) decreased its intrinsic ATPase activity and inhibited the acto-HMM-ATPase activity. Citrullinated TM resulted in stronger F-actin binding and inhibited the acto-HMM-ATPase activity. Citrullinated TnI did not alter the binding to F-actin or acto-HMM-ATPase activity. Overall, citrullination of sarcomeric proteins caused a decrease in Ca(2+) sensitivity in skinned cardiomyocytes, with no change in maximal calcium-activated force or hill coefficient. CONCLUSION Citrullination unique to the cardiac proteome was identified. Our data indicate important structural and functional alterations to the cardiac sarcomere and the contribution of protein citrullination to this process.
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Affiliation(s)
- Justyna Fert-Bober
- The Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Advanced Clinical BioSystems Research Institute, Advanced Health Science Building, 9229, Los Angeles, CA, USA Bayview Proteomics Center, Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - John T Giles
- Division of Rheumatology, Department of Medicine, Columbia University, New York, NY, USA
| | - Ronald J Holewinski
- The Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Advanced Clinical BioSystems Research Institute, Advanced Health Science Building, 9229, Los Angeles, CA, USA
| | - Jonathan A Kirk
- Division of Cardiology, Department of Medicine, The Johns Hopkins University Medical Institutions, Baltimore, MD, USA
| | - Helge Uhrigshardt
- Bayview Proteomics Center, Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
| | - Erin L Crowgey
- The Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Advanced Clinical BioSystems Research Institute, Advanced Health Science Building, 9229, Los Angeles, CA, USA
| | - Felipe Andrade
- Division of Cardiology, Department of Medicine, The Johns Hopkins University Medical Institutions, Baltimore, MD, USA
| | - Clifton O Bingham
- Division of Rheumatology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA Division of Rheumatology, Department of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Jin Kyun Park
- Division of Rheumatology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA Division of Rheumatology, Department of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Marc K Halushka
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David A Kass
- Division of Cardiology, Department of Medicine, The Johns Hopkins University Medical Institutions, Baltimore, MD, USA
| | - Joan M Bathon
- Division of Rheumatology, Department of Medicine, Columbia University, New York, NY, USA
| | - Jennifer E Van Eyk
- The Heart Institute and Department of Medicine, Cedars-Sinai Medical Center, Advanced Clinical BioSystems Research Institute, Advanced Health Science Building, 9229, Los Angeles, CA, USA Bayview Proteomics Center, Division of Cardiology, Department of Medicine, Johns Hopkins University, Baltimore, MD, USA
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Sui WH, Huang SH, Wang J, Chen Q, Liu T, Chen ZY. Myosin Va mediates BDNF-induced postendocytic recycling of full-length TrkB and its translocation into dendritic spines. J Cell Sci 2015; 128:1108-22. [PMID: 25632160 DOI: 10.1242/jcs.160259] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays an important role in neuronal survival, neurite outgrowth and synaptic plasticity by activating the receptor tropomyosin receptor kinase B (TrkB, also known as NTRK2). TrkB has been shown to undergo recycling after BDNF stimulation. We have previously reported that full-length TrkB (TrkB-FL) are recycled through a Rab11-dependent pathway upon BDNF stimuli, which is important for the translocation of TrkB-FL into dendritic spines and for the maintenance of prolonged BDNF downstream signaling during long-term potentiation (LTP). However, the identity of the motor protein that mediates the local transfer of recycled TrkB-FL back to the plasma membrane remains unclear. Here, we report that the F-actin-based motor protein myosin Va (Myo5a) mediates the postendocytic recycling of TrkB-FL. Blocking the interaction between Rab11 and Myo5a by use of a TAT-tagged peptide consisting of amino acids 55-66 of the Myo5a ExonE domain weakened the association between TrkB-FL and Myo5a and thus impaired TrkB-FL recycling and BDNF-induced TrkB-FL translocation into dendritic spines. Finally, inhibiting Myo5a-mediated TrkB-FL recycling led to a significant reduction in prolonged BDNF downstream signaling. Taken together, these results show that Myo5a mediates BDNF-dependent TrkB-FL recycling and contributes to BDNF-induced TrkB spine translocation and prolonged downstream signaling.
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Affiliation(s)
- Wen-Hai Sui
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, CAS Center for Excellence in Brain Science, School of Medicine, Shandong University, No.44 Wenhua Xi Road, Jinan, Shandong 250012, P.R. China
| | - Shu-Hong Huang
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, CAS Center for Excellence in Brain Science, School of Medicine, Shandong University, No.44 Wenhua Xi Road, Jinan, Shandong 250012, P.R. China
| | - Jue Wang
- Central Research Laboratory, The Second Hospital of Shandong University, No.247 Beiyuan Dajie, Jinan, Shandong 250033, P.R. China
| | - Qun Chen
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, CAS Center for Excellence in Brain Science, School of Medicine, Shandong University, No.44 Wenhua Xi Road, Jinan, Shandong 250012, P.R. China
| | - Ting Liu
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, CAS Center for Excellence in Brain Science, School of Medicine, Shandong University, No.44 Wenhua Xi Road, Jinan, Shandong 250012, P.R. China
| | - Zhe-Yu Chen
- Department of Neurobiology, Shandong Provincial Key Laboratory of Mental Disorders, CAS Center for Excellence in Brain Science, School of Medicine, Shandong University, No.44 Wenhua Xi Road, Jinan, Shandong 250012, P.R. China
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Toepfer C, Sellers JR. Use of fluorescent techniques to study the in vitro movement of myosins. EXPERIENTIA SUPPLEMENTUM (2012) 2014; 105:193-210. [PMID: 25095996 PMCID: PMC4178934 DOI: 10.1007/978-3-0348-0856-9_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Myosins are a large superfamily of actin-dependent molecule motors that carry out many functions in cells. Some myosins are cargo carriers that move processively along actin which means that a single molecule of myosin can take many ATP-dependent steps on actin per initial encounter. Other myosins are designed to work in large ensembles such as myosin thick filaments. In vitro motility assays are a powerful method for studying the function of myosins. These assays in general use small amounts of protein, are simple to implement, and can be done on microscopes commonly found in many laboratories. There are two basic versions of the assay which involve different geometries. In the sliding actin in vitro motility assay, myosin molecules are bound to a coverslip surface in a simply constructed microscopic flow chamber. Fluorescently labeled actin filaments are added to the flow chamber in the presence of ATP, and the movement of these actin filaments powered by the surface-bound myosins is observed. This assay has been used widely for a variety of myosins including both processive and non-processive ones. From this assay, one can easily measure the rate at which myosin is translocating actin. The single-molecule motility assay uses an inverted geometry compared to the sliding actin in vitro motility assay. It is most useful for processive myosins. Here, actin filaments are affixed to the coverslip surface. Fluorescently labeled single molecules of myosins (usually ones with processive kinetics) are introduced, and the movement of single molecules along the actin filaments is observed. This assay typically uses total internal reflection fluorescent (TIRF) microscopy to reduce the background signal arising from myosins in solution. From this assay, one can measure the velocity of movement, the frequency of movement, and the run length. If sufficient photons can be collected, one can use Gaussian fitting of the point spread function to determine the position of the labeled myosin to within a few nanometers which allows for measurement of the step size and the stepping kinetics. Together, these two assays are powerful tools to elucidate myosin function.
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Affiliation(s)
- Christopher Toepfer
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - James R. Sellers
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA
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Kodera N, Ando T. The path to visualization of walking myosin V by high-speed atomic force microscopy. Biophys Rev 2014; 6:237-260. [PMID: 25505494 PMCID: PMC4256461 DOI: 10.1007/s12551-014-0141-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 05/07/2014] [Indexed: 01/14/2023] Open
Abstract
The quest for understanding the mechanism of myosin-based motility started with studies on muscle contraction. From numerous studies, the basic frameworks for this mechanism were constructed and brilliant hypotheses were put forward. However, the argument about the most crucial issue of how the actin-myosin interaction generates contractile force and shortening has not been definitive. To increase the "directness of measurement", in vitro motility assays and single-molecule optical techniques were created and used. Consequently, detailed knowledge of the motility of muscle myosin evolved, which resulted in provoking more arguments to a higher level. In parallel with technical progress, advances in cell biology led to the discovery of many classes of myosins. Myosin V was discovered to be a processive motor, unlike myosin II. The processivity reduced experimental difficulties because it allowed continuous tracing of the motor action of single myosin V molecules. Extensive studies of myosin V were expected to resolve arguments and build a consensus but did not necessarily do so. The directness of measurement was further enhanced by the recent advent of high-speed atomic force microscopy capable of directly visualizing biological molecules in action at high spatiotemporal resolution. This microscopy clearly visualized myosin V molecules walking on actin filaments and at last provided irrefutable evidence for the swinging lever-arm motion propelling the molecules. However, a peculiar foot stomp behavior also appeared in the AFM movie, raising new questions of the chemo-mechanical coupling in this motor and myosin motors in general. This article reviews these changes in the research of myosin motility and proposes new ideas to resolve the newly raised questions.
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Affiliation(s)
- Noriyuki Kodera
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, 920-1192 Japan
- PREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, 332-0012 Japan
| | - Toshio Ando
- Bio-AFM Frontier Research Center, Kanazawa University, Kanazawa, 920-1192 Japan
- Department of Physics, College of Science and Engineering, Kanazawa University, Kakuma-machi, Kanazawa, 920-1192 Japan
- CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, 332-0012 Japan
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Abstract
Previous studies proposed that myosin-Va regulates apoptosis by sequestering pro-apoptotic Bmf to the actin cytoskeleton through dynein light chain-2 (DLC2). Adhesion loss or other cytoskeletal perturbations would unleash Bmf, allowing it to bind and inhibit pro-survival Bcl2 proteins. Here, we demonstrated that overexpression of a myosin-Va medial tail fragment (MVaf) harboring the binding site for DLC2 dramatically decreased melanoma cell viability. Morphological and molecular changes, including surface blebbing, mitochondrial outer membrane permeabilization, cytochrome-c and Smac release, as well as caspase-9/-3 activation and DNA fragmentation indicated that melanoma cells died of apoptosis. Immobilized MVaf interacted directly with DLCs, but complexed MVaf/DLCs did not interact with Bmf. Overexpression of DLC2 attenuated MVaf-induced apoptosis. Thus, we suggest that, MVaf induces apoptosis by sequestering DLC2 and DLC1, thereby unleashing the pair of sensitizer and activator BH3-only proteins Bmf and Bim. Murine embryonic fibroblasts (MEFs) lacking Bim and Bmf or Bax and Bak were less sensitive to apoptosis caused by MVaf expression than wild-type MEFs, strengthening the putative role of the intrinsic apoptotic pathway in this response. Finally, MVaf expression attenuated B16-F10 solid tumor growth in mice, suggesting that this peptide may be useful as an apoptosis-inducing tool for basic and translational studies.
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Lu Z, Shen M, Cao Y, Zhang HM, Yao LL, Li XD. Calmodulin bound to the first IQ motif is responsible for calcium-dependent regulation of myosin 5a. J Biol Chem 2012; 287:16530-40. [PMID: 22437832 DOI: 10.1074/jbc.m112.343079] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myosin 5a is as yet the best-characterized unconventional myosin motor involved in transport of organelles along actin filaments. It is well-established that myosin 5a is regulated by its tail in a Ca(2+)-dependent manner. The fact that the actin-activated ATPase activity of myosin 5a is stimulated by micromolar concentrations of Ca(2+) and that calmodulin (CaM) binds to IQ motifs of the myosin 5a heavy chain indicates that Ca(2+) regulates myosin 5a function via bound CaM. However, it is not known which IQ motif and bound CaM are responsible for the Ca(2+)-dependent regulation and how the head-tail interaction is affected by Ca(2+). Here, we found that the CaM in the first IQ motif (IQ1) is responsible for Ca(2+) regulation of myosin 5a. In addition, we demonstrate that the C-lobe fragment of CaM in IQ1 is necessary for mediating Ca(2+) regulation of myosin 5a, suggesting that the C-lobe fragment of CaM in IQ1 participates in the interaction between the head and the tail. We propose that Ca(2+) induces a conformational change of the C-lobe of CaM in IQ1 and prevents interaction between the head and the tail, thus activating motor function.
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Affiliation(s)
- Zekuan Lu
- Group of Cell Motility and Muscle Contraction, National Laboratory of Integrated Management of Insect Pests and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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13
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Calábria LK, Peixoto PMV, Passos Lima AB, Peixoto LG, de Moraes VRA, Teixeira RR, Dos Santos CT, E Silva LO, da Silva MDFR, dos Santos AAD, Garcia-Cairasco N, Martins AR, Espreafico EM, Espindola FS. Myosins and DYNLL1/LC8 in the honey bee (Apis mellifera L.) brain. JOURNAL OF INSECT PHYSIOLOGY 2011; 57:1300-1311. [PMID: 21718700 DOI: 10.1016/j.jinsphys.2011.06.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 06/09/2011] [Accepted: 06/10/2011] [Indexed: 05/31/2023]
Abstract
Honey bees have brain structures with specialized and developed systems of communication that account for memory, learning capacity and behavioral organization with a set of genes homologous to vertebrate genes. Many microtubule- and actin-based molecular motors are involved in axonal/dendritic transport. Myosin-Va is present in the honey bee Apis mellifera nervous system of the larvae and adult castes and subcastes. DYNLL1/LC8 and myosin-IIb, -VI and -IXb have also been detected in the adult brain. SNARE proteins, such as CaMKII, clathrin, syntaxin, SNAP25, munc18, synaptophysin and synaptotagmin, are also expressed in the honey bee brain. Honey bee myosin-Va displayed ATP-dependent solubility and was associated with DYNLL1/LC8 and SNARE proteins in the membrane vesicle-enriched fraction. Myosin-Va expression was also decreased after the intracerebral injection of melittin and NMDA. The immunolocalization of myosin-Va and -IV, DYNLL1/LC8, and synaptophysin in mushroom bodies, and optical and antennal lobes was compared with the brain morphology based on Neo-Timm histochemistry and revealed a distinct and punctate distribution. This result suggested that the pattern of localization is associated with neuron function. Therefore, our data indicated that the roles of myosins, DYNLL1/LC8, and SNARE proteins in the nervous and visual systems of honey bees should be further studied under different developmental, caste and behavioral conditions.
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Affiliation(s)
- Luciana Karen Calábria
- Institute of Genetics and Biochemistry, Federal University of Uberlandia, Uberlandia, MG, Brazil.
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14
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Abstract
In neuroscience, myosin V motor proteins have attracted attention since they are highly expressed in brain, and absence of myosin Va in man leads to a severe neurological disease called Griscelli syndrome. While in some cells myosin V is described to act as a vesicle transport motor, an additional role in exocytosis has emerged recently. In neurons, myosin V has been linked to exocytosis of secretory vesicles and recycling endosomes. Through these functions, it is implied in regulating important brain functions including the release of neuropeptides by exocytosis of large dense-core vesicles and the insertion of neurotransmitter receptors into post-synaptic membranes. This review focuses on the role of myosin V in (i) axonal transport and stimulated exocytosis of large dense-core vesicles to regulate the secretion of neuroactive substances, (ii) tethering of the endoplasmic reticulum at cerebellar synapses to permit long-term depression, (iii) recycling of α-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) receptors at hippocampal synapses during long-term potentiation, and (iv) recycling of nicotinic acetylcholine receptors at the neuromuscular junction. Myosin V is thus discussed as an important modulator of synaptic plasticity.
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Affiliation(s)
- Rüdiger Rudolf
- Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
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15
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Kelly EE, Horgan CP, McCaffrey MW, Young P. The role of endosomal-recycling in long-term potentiation. Cell Mol Life Sci 2011; 68:185-94. [PMID: 20820847 PMCID: PMC11114889 DOI: 10.1007/s00018-010-0516-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 08/06/2010] [Accepted: 08/17/2010] [Indexed: 11/26/2022]
Abstract
Long-term potentiation (LTP) defines persistent increases in neurotransmission strength at synapses that are triggered by specific patterns of neuronal activity. LTP, the most widely accepted molecular model for learning, is best characterised at glutamatergic synapses on dendritic spines. In this context, LTP involves increases in dendritic spine size and the insertion of glutamate receptors into the post-synaptic spine membrane, which together boost post-synaptic responsiveness to neurotransmitters. In dendrites, the material required for LTP is sourced from an organelle termed the endosomal-recycling compartment (ERC), which is localised to the base of dendritic spines. When LTP is induced, material derived from the recycling compartment, which contains α-amino-3-hydroxy-5-methyl-4-isoxazole propionate-type glutamate receptors (AMPARs), is mobilised into dendritic spines feeding the increased need for receptors and membrane at the spine neck and head. In this review, we discuss the importance of endosomal-recycling and the role of key proteins which control these processes in the context of LTP.
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Affiliation(s)
- Eoin E Kelly
- Department of Biochemistry, BioSciences Institute, University College Cork, Ireland.
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16
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Denatured proteins facilitate the formation of the football-shaped GroEL-(GroES)2 complex. Biochem J 2010; 427:247-54. [PMID: 20121703 DOI: 10.1042/bj20091845] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Controversy exists over whether the chaperonin GroEL forms a GroEL-(GroES)2 complex (football-shaped complex) during its reaction cycle. We have revealed previously the existence of the football-shaped complex in the chaperonin reaction cycle using a FRET (fluorescence resonance energy transfer) assay [Sameshima, Ueno, Iizuka, Ishii, Terada, Okabe and Funatsu (2008) J. Biol. Chem. 283, 23765-23773]. Although denatured proteins alter the ATPase activity of GroEL and the dynamics of the GroEL-GroES interaction, the effect of denatured proteins on the formation of the football-shaped complex has not been characterized. In the present study, a FRET assay was used to demonstrate that denatured proteins facilitate the formation of the football-shaped complex. The presence of denatured proteins was also found to increase the rate of association of GroES to the trans-ring of GroEL. Furthermore, denatured proteins decrease the inhibitory influence of ADP on ATP-induced association of GroES to the trans-ring of GroEL. From these findings we conclude that denatured proteins facilitate the dissociation of ADP from the trans-ring of GroEL and the concomitant association of ATP and the second GroES.
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17
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Higashi-Fujime S, Nakamura A. Cell and molecular biology of the fastest myosins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2009; 276:301-47. [PMID: 19584016 DOI: 10.1016/s1937-6448(09)76007-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Chara myosin is a class XI plant myosin in green algae Chara corallina and responsible for fast cytoplasmic streaming. The Chara myosin exhibits the fastest sliding movement of F-actin at 60 mum/s as observed so far, 10-fold of the shortening speed of muscle. It has some distinct properties differing from those of muscle myosin. Although knowledge about Chara myosin is very limited at present, we have tried to elucidate functional bases of its characteristics by comparing with those of other myosins. In particular, we have built the putative atomic model of Chara myosin by using the homology-based modeling system and databases. Based on the putative structure of Chara myosin obtained, we have analyzed the relationship between structure and function of Chara myosin to understand its distinct properties from various aspects by referring to the accumulated knowledge on mechanochemical and structural properties of other classes of myosin, particularly animal and fungal myosin V. We will also discuss the functional significance of Chara myosin in a living cell.
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Affiliation(s)
- Sugie Higashi-Fujime
- Department of Molecular and Cellular Pharmacology, Gunma University Graduate School of Medicine, Maebashi, Gunma, Japan
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18
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Wang Z, Edwards JG, Riley N, Provance DW, Karcher R, Li XD, Davison IG, Ikebe M, Mercer JA, Kauer JA, Ehlers MD. Myosin Vb mobilizes recycling endosomes and AMPA receptors for postsynaptic plasticity. Cell 2008; 135:535-48. [PMID: 18984164 DOI: 10.1016/j.cell.2008.09.057] [Citation(s) in RCA: 367] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2008] [Revised: 07/16/2008] [Accepted: 09/09/2008] [Indexed: 10/21/2022]
Abstract
Learning-related plasticity at excitatory synapses in the mammalian brain requires the trafficking of AMPA receptors and the growth of dendritic spines. However, the mechanisms that couple plasticity stimuli to the trafficking of postsynaptic cargo are poorly understood. Here we demonstrate that myosin Vb (MyoVb), a Ca2+-sensitive motor, conducts spine trafficking during long-term potentiation (LTP) of synaptic strength. Upon activation of NMDA receptors and corresponding Ca2+ influx, MyoVb associates with recycling endosomes (REs), triggering rapid spine recruitment of endosomes and local exocytosis in spines. Disruption of MyoVb or its interaction with the RE adaptor Rab11-FIP2 abolishes LTP-induced exocytosis from REs and prevents both AMPA receptor insertion and spine growth. Furthermore, induction of tight binding of MyoVb to actin using an acute chemical genetic strategy eradicates LTP in hippocampal slices. Thus, Ca2+-activated MyoVb captures and mobilizes REs for AMPA receptor insertion and spine growth, providing a mechanistic link between the induction and expression of postsynaptic plasticity.
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Affiliation(s)
- Zhiping Wang
- Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA; Howard Hughes Medical Institute, Duke University Medical Center, Durham, NC 27710, USA
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19
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Watanabe S, Umeki N, Ikebe R, Ikebe M. Impacts of Usher syndrome type IB mutations on human myosin VIIa motor function. Biochemistry 2008; 47:9505-13. [PMID: 18700726 DOI: 10.1021/bi8007142] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Usher syndrome (USH) is a human hereditary disorder characterized by profound congenital deafness, retinitis pigmentosa, and vestibular dysfunction. Myosin VIIa has been identified as the responsible gene for USH type 1B, and a number of missense mutations have been identified in the affected families. However, the molecular basis of the dysfunction of USH gene, myosin VIIa, in the affected families is unknown to date. Here we clarified the effects of USH1B mutations on human myosin VIIa motor function for the first time. The missense mutations of USH1B significantly inhibited the actin activation of ATPase activity of myosin VIIa. G25R, R212C, A397D, and E450Q mutations abolished the actin-activated ATPase activity completely. P503L mutation increased the basal ATPase activity for 2-3-fold but reduced the actin-activated ATPase activity to 50% of the wild type. While all of the mutations examined, except for R302H, reduced the affinity for actin and the ATP hydrolysis cycling rate, they did not largely decrease the rate of ADP release from actomyosin, suggesting that the mutations reduce the duty ratio of myosin VIIa. Taken together, the results suggest that the mutations responsible for USH1B cause the complete loss of the actin-activated ATPase activity or the reduction of duty ratio of myosin VIIa.
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Affiliation(s)
- Shinya Watanabe
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
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20
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Calcium-activated Myosin V closes the Drosophila pupil. Curr Biol 2008; 18:951-5. [PMID: 18585038 DOI: 10.1016/j.cub.2008.05.046] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2008] [Revised: 05/19/2008] [Accepted: 05/21/2008] [Indexed: 11/24/2022]
Abstract
Approximately 40 years ago, an elegant automatic-gain control was revealed in compound eye photoreceptors: In bright light, an assembly of small pigment granules migrates to the cytoplasmic face of the photosensitive membrane organelle, the rhabdomere, where they attenuate waveguide propagation along the rhabdomere. This migration results in a "longitudinal pupil" that reduces rhodopsin exposure by a factor of 0.8 log units. Light-induced elevation of cytosolic free Ca(2+) triggers the migration of pigment granules, and pigment granules fail to migrate in a mutant deficient in photoactivated TRP calcium channels. However, the mechanism that moves photoreceptor pigment granules remains elusive. Are the granules actively pulled toward the rhabdomere upon light, or are they instead actively pulled into the cytoplasm in the absence of light? Here we show that Ca(2+)-activated Myosin V (MyoV) pulls pigment granules to the rhabdomere. Thus, one of MyoV's several functions is also as a sensory-adaptation motor. In vitro, Ca(2+) both activates and inhibits MyoV motility; in vivo, its role is undetermined. This first demonstration of an in vivo role for Ca(2+) in MyoV activity shows that in Drosophila photoreceptors, Ca(2+) stimulates MyoV motility.
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21
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Localization of myosin-Va in subpopulations of cells in rat endocrine organs. Cell Tissue Res 2008; 333:263-79. [PMID: 18568366 DOI: 10.1007/s00441-008-0630-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2007] [Accepted: 04/30/2008] [Indexed: 10/22/2022]
Abstract
Myosin-Va is a Ca(2+)/calmodulin-regulated unconventional myosin involved in the transport of vesicles, membranous organelles, and macromolecular complexes composed of proteins and mRNA. The cellular localization of myosin-Va has been described in great detail in several vertebrate cell types, including neurons, melanocytes, lymphocytes, auditory tissues, and a number of cultured cells. Here, we provide an immunohistochemical view of the tissue distribution of myosin-Va in the major endocrine organs. Myosin-Va is highly expressed in the pineal and pituitary glands and in specific cell populations of other endocrine glands, especially the parafollicular cells of the thyroid, the principal cells of the parathyroid, the islets of Langerhans of the pancreas, the chromaffin cells of the adrenal medulla, and a subpopulation of interstitial testicular cells. Weak to moderate staining has been detected in steroidogenic cells of the adrenal cortex, ovary, and Leydig cells. Myosin-Va has also been localized to non-endocrine cells, such as the germ cells of the seminiferous epithelium and maturing oocytes and in the intercalated ducts of the exocrine pancreas. These data provide the first systematic description of myosin-Va localization in the major endocrine organs of rat.
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22
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Abstract
Myosin V (myoV), a processive cargo transporter, has arguably been the most well-studied unconventional myosin of the past decade. Considerable structural information is available for the motor domain, the IQ motifs with bound calmodulin or light chains, and the cargo-binding globular tail, all of which have been crystallized. The repertoire of adapter proteins that link myoV to a particular cargo is becoming better understood, enabling cellular transport processes to be dissected. MyoV is processive, meaning that it takes many steps on actin filaments without dissociating. Its extended lever arm results in long 36-nm steps, making it ideal for single molecule studies of processive movement. In addition, electron microscopy revealed the structure of the inactive, folded conformation of myoV when it is not transporting cargo. This review provides a background on myoV, and highlights recent discoveries that show why myoV will continue to be an active focus of investigation.
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Affiliation(s)
- K M Trybus
- Department of Molecular Physiology and Biophysics, 149 Beaumont Avenue, University of Vermont, Burlington, Vermont 05405, USA.
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23
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Sellers JR. In vitro motility assay to study translocation of actin by myosin. ACTA ACUST UNITED AC 2008; Chapter 13:Unit 13.2. [PMID: 18228321 DOI: 10.1002/0471143030.cb1302s00] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A basic property of myosin is its ability to interact with and translocate actin. This unit describes an in vitro motility assay that can be used to study the translocation, or sliding, of actin filaments by myosin bound to a coverslip. The assay makes use of the ability to image single F-actin filaments labeled with rhodamine phalloidin, a high-affinity fluorescent ligand using fluorescence microscopy. The system is fast, easy to set up and maintain, uses only small amounts of protein, and yields quantitative results.
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Affiliation(s)
- J R Sellers
- National Heart, Lung, and Blood Institute, Bethesda, Maryland, USA
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24
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The globular tail domain puts on the brake to stop the ATPase cycle of myosin Va. Proc Natl Acad Sci U S A 2008; 105:1140-5. [PMID: 18216256 DOI: 10.1073/pnas.0709741105] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Myosin Va is a well known processive motor involved in transport of organelles. A tail-inhibition model is generally accepted for the regulation of myosin Va: inhibited myosin Va is in a folded conformation such that the tail domain interacts with and inhibits myosin Va motor activity. Recent studies indicate that it is the C-terminal globular tail domain (GTD) that directly inhibits the motor activity of myosin Va. In the present study, we identified a conserved acidic residue in the motor domain (Asp-136) and two conserved basic residues in the GTD (Lys-1706 and Lys-1779) as critical residues for this regulation. Alanine mutations of these conserved charged residues not only abolished the inhibition of motor activity by the GTD but also prevented myosin Va from forming a folded conformation. We propose that Asp-136 forms ionic interactions with Lys-1706 and Lys-1779. This assignment locates the GTD-binding site in a pocket of the motor domain, formed by the N-terminal domain, converter, and the calmodulin in the first IQ motif. We propose that binding of the GTD to the motor domain prevents the movement of the converter/lever arm during ATP hydrolysis cycle, thus inhibiting the chemical cycle of the motor domain.
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25
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Takagi Y, Yang Y, Fujiwara I, Jacobs D, Cheney RE, Sellers JR, Kovács M. Human myosin Vc is a low duty ratio, nonprocessive molecular motor. J Biol Chem 2008; 283:8527-37. [PMID: 18201966 DOI: 10.1074/jbc.m709150200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Myosin Vc is the product of one of the three genes of the class V myosin found in vertebrates. It is widely found in secretory and glandular tissues, with a possible involvement in transferrin trafficking. Transient and steady-state kinetic studies of human myosin Vc were performed using a truncated, single-headed construct. Steady-state actin-activated ATPase measurements revealed a V(max) of 1.8 +/- 0.3 s(-1) and a K(ATPase) of 43 +/- 11 microm. Unlike previously studied vertebrate myosin Vs, the rate-limiting step in the actomyosin Vc ATPase pathway is the release of inorganic phosphate (~1.5 s(-1)), rather than the ADP release step (~12.0-16.0 s(-1)). Nevertheless, the ADP affinity of actomyosin Vc (K(d) = 0.25 +/- 0.02 microm) reflects a higher ADP affinity than seen in other myosin V isoforms. Using the measured kinetic rates, the calculated duty ratio of myosin Vc was approximately 10%, indicating that myosin Vc spends the majority of the actomyosin ATPase cycle in weak actin-binding states, unlike the other vertebrate myosin V isoforms. Consistent with this, a fluorescently labeled double-headed heavy meromyosin form showed no processive movements along actin filaments in a single molecule assay, but it did move actin filaments at a velocity of approximately 24 nm/s in ensemble assays. Kinetic simulations reveal that the high ADP affinity of actomyosin Vc may lead to elevations of the duty ratio of myosin Vc to as high as 64% under possible physiological ADP concentrations. This, in turn, may possibly imply a regulatory mechanism that may be sensitive to moderate changes in ADP concentration.
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Affiliation(s)
- Yasuharu Takagi
- Laboratory of Molecular Physiology, NHLBI, NIH, Bethesda, MD 20892-8015, USA
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26
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Marese ACM, de Freitas P, Natali MRM. Alterations of the number and the profile of myenteric neurons of Wistar rats promoted by age. Auton Neurosci 2007; 137:10-8. [PMID: 17574931 DOI: 10.1016/j.autneu.2007.05.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Revised: 04/18/2007] [Accepted: 05/01/2007] [Indexed: 11/27/2022]
Abstract
The objective of this study was to analyze the morpho quantitative behaviour of duodenum myenteric neurons of Wistar rats (Rattus norvegicus), aged 21, 60, 90, 210, 345 and 428 days, using wholemount preparations of the muscular tunica obtained by dissecting the intestinal tunica for neuronal revealing, through the Giemsa non-histochemical and Myosin-V immunohistochemical techniques. The neurons were quantified in 80 microscopic fields (14.832 mm(2)) for each animal and neuronal cell body morphometry was carried out on 100 neurons/rat. Duodenal samples were submitted to histological routine processing, stained by hematoxylin-eosin method in order to perform morphometric analysis of the muscular tunica. An increase in the length of the small intestine was observed up to the age of 60 days, which was maintained up to 210 days, with a reduction in this parameter from 345 days. Muscular tunica thickness was maintained independently of the animal age. During the course of the study, there was a reduction in the mean neuron population in both techniques used. However, in all of the ages evaluated, the use of the Myosin-V technique lead to a reduced mean number of neurons compared to the Giemsa method. The cellular profile morphometry revealed, with both techniques, the predominance of smaller neurons in young animals, and bigger neurons in animals from higher age groups. It was concluded that advanced age is a determinant factor in the number reduction of myenteric neurons, with maintenance of the intrinsic intestinal innervation by the remaining neurons and that the use of the Giemsa non-histochemical technique showed itself more adequate to determine the total neuronal population.
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Affiliation(s)
- Angélica Cristina Milan Marese
- Department of Morphophysiological Sciences, Enteric Neurons Laboratory, State University of Maringá, Avenida Colombo, 5790, 87020-900, Maringá, Paraná, Brazil.
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27
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Ganoth A, Nachliel E, Friedman R, Gutman M. Myosin V movement: lessons from molecular dynamics studies of IQ peptides in the lever arm. Biochemistry 2007; 46:14524-36. [PMID: 18020453 DOI: 10.1021/bi701342y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Myosin V moves along actin filaments by an arm-over-arm motion, known as the lever mechanism. Each of its arms is composed of six consecutive IQ peptides that bind light chain proteins, such as calmodulin or calmodulin-like proteins. We have employed a multistage approach in order to investigate the mechanochemical structural basis of the movement of myosin V from the budding yeast Saccharomyces cerevisiae. For that purpose, we previously carried out molecular dynamics simulations of the Mlc1p-IQ2 and the Mlc1p-IQ4 protein-peptide complexes, and the present study deals with the structures of the IQ peptides when stripped from the Mlc1p protein. We have found that the crystalline structure of the IQ2 peptide retains a stable rodlike configuration in solution, whereas that of the IQ4 peptide grossly deviates from its X-ray conformation exhibiting an intrinsic tendency to curve and bend. The refolding process of the IQ4 peptide is initially driven by electrostatic interactions followed by nonpolar stabilization. Its bending appears to be affected by the ionic strength, when ionic strength higher than approximately 300 mM suppresses it from flexing. Considering that a poly-IQ sequence is the lever arm of myosin V, we suggest that the arm may harbor a joint, localized within the IQ4 sequence, enabling the elasticity of the neck of myosin V. Given that a poly-IQ sequence is present at the entire class of myosin V and the possibility that the yeast's myosin V molecule can exist either as a nonprocessive monomer or as a processive dimer depending on conditions (Krementsova, E. B., Hodges, A. R., Lu, H., and Trybus, K. M. (2006) J. Biol. Chem. 281, 6079-6086), our observations may account for a general structural feature for the myosins' arm embedded flexibility.
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Affiliation(s)
- Assaf Ganoth
- Laser Laboratory for Fast Reactions in Biology, Department of Biochemistry, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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28
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Desnos C, Huet S, Darchen F. 'Should I stay or should I go?': myosin V function in organelle trafficking. Biol Cell 2007; 99:411-23. [PMID: 17635110 DOI: 10.1042/bc20070021] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Actin- and microtubule-based motors can propel different cargos along filaments. Within cells, they control the distribution of membrane-bound compartments by performing complementary tasks. Organelles make long journeys along microtubules, with class V myosins ensuring their capture and their dispersal in actin-rich regions. Myosin Va is recruited on to diverse organelles, such as melanosomes and secretory vesicles, by a mechanism involving Rab GTPases. The role of myosin Va in the recruitment of secretory vesicles at the plasma membrane reveals that the cortical actin network cannot merely be seen as a physical barrier hindering vesicle access to release sites. In neurons, myosin Va controls the targeting of IP(3) (inositol 1,4,5-trisphosphate)-sensitive Ca(2+) stores to dendritic spines and the transport of mRNAs. These defects probably account for the severe neurological symptoms observed in Griscelli syndrome due to mutations in the MYO5A gene.
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Affiliation(s)
- Claire Desnos
- Institut de Biologie Physico-Chimique, Centre National de la Recherche Scientifique, UPR 1929, Université Paris 7 Denis Diderot, Paris, France.
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29
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Yoshizaki T, Imamura T, Babendure JL, Lu JC, Sonoda N, Olefsky JM. Myosin 5a is an insulin-stimulated Akt2 (protein kinase Bbeta) substrate modulating GLUT4 vesicle translocation. Mol Cell Biol 2007; 27:5172-83. [PMID: 17515613 PMCID: PMC1951956 DOI: 10.1128/mcb.02298-06] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Phosphatidylinositol 3-kinase activation of Akt signaling is critical to insulin-stimulated glucose transport and GLUT4 translocation. However, the downstream signaling events following Akt activation which mediate glucose transport stimulation remain relatively unknown. Here we identify an Akt consensus phosphorylation motif in the actin-based motor protein myosin 5a and show that insulin stimulation leads to phosphorylation of myosin 5a at serine 1650. This Akt-mediated phosphorylation event enhances the ability of myosin 5a to interact with the actin cytoskeleton. Small interfering RNA-induced inhibition of myosin 5a and expression of dominant-negative myosin 5a attenuate insulin-stimulated glucose transport and GLUT4 translocation. Furthermore, knockdown of Akt2 or expression of dominant-negative Akt (DN-Akt) abolished insulin-stimulated phosphorylation of myosin 5a, inhibited myosin 5a binding to actin, and blocked insulin-stimulated glucose transport. Taken together, these data indicate that myosin 5a is a newly identified direct substrate of Akt2 and, upon insulin stimulation, phosphorylated myosin 5a facilitates anterograde movement of GLUT4 vesicles along actin to the cell surface.
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Affiliation(s)
- Takeshi Yoshizaki
- Department of Medicine (0673), University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0673, USA
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30
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Rancura KGO, Montaño MR, Carvalho RF, Martins C, Wasko AP, Casaletti L, Azevedo A. Brain distribution of myosin Va in rainbow trout Oncorhynchus mykiss. ACTA ZOOL-STOCKHOLM 2007. [DOI: 10.1111/j.1463-6395.2007.00289.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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31
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Lu H, Krementsova EB, Trybus KM. Regulation of Myosin V Processivity by Calcium at the Single Molecule Level. J Biol Chem 2006. [DOI: 10.1016/s0021-9258(19)84112-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Lu H, Krementsova EB, Trybus KM. Regulation of myosin V processivity by calcium at the single molecule level. J Biol Chem 2006; 281:31987-94. [PMID: 16920704 DOI: 10.1074/jbc.m605181200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Calcium can affect myosin V (myoV) function in at least two ways. The full-length molecule, which adopts a folded inhibited conformation in EGTA, becomes extended and active in the presence of calcium. Calcium also dissociates one or more calmodulin molecules from the extended neck. Here we investigated at the single molecule level how calcium regulates the processive run length of full-length myosin V (dFull) and a truncated dimeric construct (dHMM), which cannot adopt the folded conformation. The processivity of dFull and dHMM is tightly controlled by the calcium and calmodulin concentration, with shorter runs occurring at higher calcium concentration. The data indicate that a calcium-dependent dissociation of calmodulin from the neck region of myoV terminates its processive run. dFull showed unexpected processive movement in EGTA, suggesting that a small population of extended, active molecules are in equilibrium with the inhibited, folded form. Single turnover assays showed that the ATPase activity of the folded full-length molecule is inhibited by more than 50-fold compared with the extended molecule. The results imply that activation and termination of the processive runs of myoV can be accomplished by multiple mechanisms.
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Affiliation(s)
- Hailong Lu
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405, USA
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34
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Olivares AO, Chang W, Mooseker MS, Hackney DD, De La Cruz EM. The tail domain of myosin Va modulates actin binding to one head. J Biol Chem 2006; 281:31326-36. [PMID: 16921171 DOI: 10.1074/jbc.m603898200] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Calcium activates full-length myosin Va steady-state enzymatic activity and favors the transition from a compact, folded "off" state to an extended "on" state. However, little is known of how a head-tail interaction alters the individual actin and nucleotide binding rate and equilibrium constants of the ATPase cycle. We measured the effect of calcium on nucleotide and actin filament binding to full-length myosin Va purified from chick brains. Both heads of nucleotide-free myosin Va bind actin strongly, independent of calcium. In the absence of calcium, bound ADP weakens the affinity of one head for actin filaments at equilibrium and upon initial encounter. The addition of calcium allows both heads of myosin Va.ADP to bind actin strongly. Calcium accelerates ADP binding to actomyosin independent of the tail but minimally affects ATP binding. Although 18O exchange and product release measurements favor a mechanism in which actin-activated Pi release from myosin Va is very rapid, independent of calcium and the tail domain, both heads do not bind actin strongly during steady-state cycling, as assayed by pyrene actin fluorescence. In the absence of calcium, inclusion of ADP favors formation of a long lived myosin Va.ADP state that releases ADP slowly, even after mixing with actin. Our results suggest that calcium activates myosin Va by allowing both heads to interact with actin and exchange bound nucleotide and indicate that regulation of actin binding by the tail is a nucleotide-dependent process favored by linked conformational changes of the motor domain.
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Affiliation(s)
- Adrian O Olivares
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520, USA
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35
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O'Connell CB, Tyska MJ, Mooseker MS. Myosin at work: motor adaptations for a variety of cellular functions. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1773:615-30. [PMID: 16904206 DOI: 10.1016/j.bbamcr.2006.06.012] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2006] [Revised: 05/22/2006] [Accepted: 06/30/2006] [Indexed: 12/30/2022]
Abstract
Cells have evolved multiple mechanisms to overcome the effects of entropy and diffusion to create a highly ordered environment. For cells to function properly, some components must be anchored to provide a framework or structure. Others must be rapidly transported over long distances to generate asymmetries in cell morphology and composition. To accomplish long-range transport, cells cannot rely on diffusion alone as many large organelles and macromolecular complexes are essentially immobilized by the dense meshwork of the cytosol. One strategy used by cells to overcome diffusion is to harness the free energy liberated by ATP hydrolysis through molecular motors. Myosins are a family of actin based molecular motors that have evolved a variety of ways to contribute to cellular organization through numerous modifications to the manner they convert that free energy into mechanical work.
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36
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Terrak M, Rebowski G, Lu RC, Grabarek Z, Dominguez R. Structure of the light chain-binding domain of myosin V. Proc Natl Acad Sci U S A 2005; 102:12718-23. [PMID: 16120677 PMCID: PMC1200277 DOI: 10.1073/pnas.0503899102] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Myosin V is a double-headed molecular motor involved in organelle transport. Two distinctive features of this motor, processivity and the ability to take extended linear steps of approximately 36 nm along the actin helical track, depend on its unusually long light chain-binding domain (LCBD). The LCBD of myosin V consists of six tandem IQ motifs, which constitute the binding sites for calmodulin (CaM) and CaM-like light chains. Here, we report the 2-A resolution crystal structure of myosin light chain 1 (Mlc1p) bound to the IQ2-IQ3 fragment of Myo2p, a myosin V from Saccharomyces cerevisiae. This structure, combined with FRET distance measurements between probes in various CaM-IQ complexes, comparative sequence analysis, and the previously determined structures of Mlc1p-IQ2 and Mlc1p-IQ4, allowed building a model of the LCBD of myosin V. The IQs of myosin V are distributed into three pairs. There appear to be specific cooperative interactions between light chains within each IQ pair, but little or no interaction between pairs, providing flexibility at their junctions. The second and third IQ pairs each present a light chain, whether CaM or a CaM-related molecule, bound in a noncanonical extended conformation in which the N-lobe does not interact with the IQ motif. The resulting free N-lobes may engage in protein-protein interactions. The extended conformation is characteristic of the single IQ of myosin VI and is common throughout the myosin superfamily. The model points to a prominent role of the LCBD in the function, regulation, and molecular interactions of myosin V.
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Affiliation(s)
- Mohammed Terrak
- Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA
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37
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Watanabe M, Nomura K, Ohyama A, Ishikawa R, Komiya Y, Hosaka K, Yamauchi E, Taniguchi H, Sasakawa N, Kumakura K, Ushiki T, Sato O, Ikebe M, Igarashi M. Myosin-Va regulates exocytosis through the submicromolar Ca2+-dependent binding of syntaxin-1A. Mol Biol Cell 2005; 16:4519-30. [PMID: 16030255 PMCID: PMC1237061 DOI: 10.1091/mbc.e05-03-0252] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Myosin-Va is an actin-based processive motor that conveys intracellular cargoes. Synaptic vesicles are one of the most important cargoes for myosin-Va, but the role of mammalian myosin-Va in secretion is less clear than for its yeast homologue, Myo2p. In the current studies, we show that myosin-Va on synaptic vesicles interacts with syntaxin-1A, a t-SNARE involved in exocytosis, at or above 0.3 microM Ca2+. Interference with formation of the syntaxin-1A-myosin-Va complex reduces the exocytotic frequency in chromaffin cells. Surprisingly, the syntaxin-1A-binding site was not in the tail of myosin-Va but rather in the neck, a region that contains calmodulin-binding IQ-motifs. Furthermore, we found that syntaxin-1A binding by myosin-Va in the presence of Ca2+ depends on the release of calmodulin from the myosin-Va neck, allowing syntaxin-1A to occupy the vacant IQ-motif. Using an anti-myosin-Va neck antibody, which blocks this binding, we demonstrated that the step most important for the antibody's inhibitory activity is the late sustained phase, which is involved in supplying readily releasable vesicles. Our results demonstrate that the interaction between myosin-Va and syntaxin-1A is involved in exocytosis and suggest that the myosin-Va neck contributes not only to the large step size but also to the regulation of exocytosis by Ca2+.
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Affiliation(s)
- Michitoshi Watanabe
- Division of Molecular and Cellular Biology, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Niigata 951-8510, Japan
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38
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Isogawa Y, Kon T, Inoue T, Ohkura R, Yamakawa H, Ohara O, Sutoh K. The N-terminal domain of MYO18A has an ATP-insensitive actin-binding site. Biochemistry 2005; 44:6190-6. [PMID: 15835906 DOI: 10.1021/bi0475931] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Myosin XVIII is the recently identified 18th class of myosins, and its members are composed of a unique N-terminal domain, a motor domain with an unusual sequence around the ATPase site, one IQ motif, a segmented coiled-coil region for dimerization, and a C-terminal globular tail. To gain insight into the functions of this unique myosin, we characterized its human homologue, MYO18A, focusing on the functional roles of the characteristic N-terminal domain that contains a PDZ module known to mediate protein-protein interaction. GFP-tagged full-length and C-terminally truncated MYO18A molecules that were expressed in HeLa cells exhibited colocalization with actin filaments. Chemical cross-linking of these molecules showed that they form stable dimers as expected from their putative coiled-coil tails. Cosedimentation of the various types of truncated MYO18A constructs with actin filaments indicated the presence of an ATP-insensitive actin-binding site in the N-terminal domain. Further studies on truncated constructs of the N-terminal domain indicated that this actin-binding site is located outside the PDZ module, but within the middle region of this domain, which does not show any homology with the known actin-binding motifs. These results imply that this dimeric myosin might stably cross-link actin filaments by two ATP-insensitive actin-binding sites at the N-terminal domains for higher-order organization of the actin cytoskeleton.
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Affiliation(s)
- Yasushi Isogawa
- Department of Life Sciences, Graduate School of Arts and Sciences, University of Tokyo, 3-8-1 Komaba, Tokyo 153-8902, Japan
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39
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Nguyen H, Higuchi H. Motility of myosin V regulated by the dissociation of single calmodulin. Nat Struct Mol Biol 2005; 12:127-32. [PMID: 15665867 DOI: 10.1038/nsmb894] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2004] [Accepted: 12/16/2004] [Indexed: 11/09/2022]
Abstract
Myosin V is a calmodulin-binding motor protein. The dissociation of single calmodulin molecules from individual myosin V molecules at 1 microM Ca(2+) correlates with a reduction in sliding velocity in an in vitro motility assay. The dissociation of two calmodulin molecules at 5 microM Ca(2+) correlates with a detachment of actin filaments from myosin V. To mimic the regulation of myosin V motility by Ca(2+) in a cell, caged Ca(2+) coupled with a UV flash system was used to produce Ca(2+) transients. During the Ca(2+) transient, myosin V goes through the functional cycle of reduced sliding velocity, actin detachment and reattachment followed by the recovery of the sliding velocity. These results indicate that myosin V motility is regulated by Ca(2+) through a reduction in actin-binding affinity resulting from the dissociation of single calmodulin molecules.
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Affiliation(s)
- HoaAnh Nguyen
- Center for Interdisciplinary Research, Tohoku University, Sendai 980-8578, Japan
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40
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Ando T, Kodera N, Naito Y, Kinoshita T, Furuta K, Toyoshima YY. A high-speed atomic force microscope for studying biological macromolecules in action. Chemphyschem 2004; 4:1196-202. [PMID: 14652998 DOI: 10.1002/cphc.200300795] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The atomic force microscope (AFM), which was invented by Binnig et al. in 1986, can image at nanometer resolution individual biological macromolecules on a substrate in solution. This unique capability awoke an expectation of imaging processes occurring in biological macromolecules at work. However, this expectation was not met, because the imaging rate with available AFMs was too low to capture biological processes. This expectation has at last been realized by the high-speed AFM developed by our research group at Kanazawa University. In this article, after a brief review of the development of our apparatus, its recent advancement and imaging data obtained with motor proteins are presented.
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Affiliation(s)
- Toshio Ando
- Department of Physics, Kanazawa University, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan.
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41
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Alavez S, Morán J, Franco-Cea A, Ortega-Gómez A, Casaletti L, Cameron LC. Myosin Va is proteolysed in rat cerebellar granule neurons after excitotoxic injury. Neurosci Lett 2004; 367:404-9. [PMID: 15337275 DOI: 10.1016/j.neulet.2004.06.043] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Revised: 06/16/2004] [Accepted: 06/18/2004] [Indexed: 11/24/2022]
Abstract
Cerebellar granule neurons when exposed to glutamate die through an excitotoxic mechanism induced by overactivation of glutamate receptors. This kind of cell death is mediated by an overload of intracellular calcium involving calpain activation, a Ca2+ -dependent intracellular cysteine protease, among other intracellular responses. On the other hand, class V myosins are proteins that move cargo along actin filaments and one of its members, myosin Va, is involved in vesicles transport. Here we studied the effect of excitotoxicity on myosin Va in cultured cerebellar granule neurons. Western blot analysis of control cultures shows a band corresponding to myosin Va as well as an 80 kDa band corresponding to its proteolytic product by calpain. When cells are exposed to glutamate (500 microM), kainate (100 microM) or NMDA (150 microM) during 3-24 h, the proteolytic processing of myosin Va is markedly increased. This proteolysis is inhibited by leupeptin (100 microM) and calpain inhibitor I (50 microM). These inhibitors also significantly improve the morphological appearance of the neurons possibly through the preservation of the cytoskeleton integrity. Our results suggest that myosin Va is a target for calpain I during an excitotoxic injury and could lead to a new area of research to address the participation of molecular motors in neurotoxicity.
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Affiliation(s)
- Silvestre Alavez
- Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Neurociencias, Apartado Postal 70-253, 04510, DF, Mexico.
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42
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Martin SR, Bayley PM. Calmodulin bridging of IQ motifs in myosin-V. FEBS Lett 2004; 567:166-70. [PMID: 15178316 DOI: 10.1016/j.febslet.2004.04.053] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2004] [Revised: 04/14/2004] [Accepted: 04/23/2004] [Indexed: 11/18/2022]
Abstract
Ca(2+)-saturated calmodulin binds to double-length IQ lever-arm sequences from murine myosin-V, forming a 1:1 "bridging" complex with very high affinity, (K9d)<10 pM for double motifs, IQ34, IQ45 and IQ56). Such a 1:1 complex involves interaction of one calmodulin (CaM) molecule with two adjacent IQ-motifs, providing a molecular mechanism for the observed Ca(2+)-dependent CaM dissociation from the IQ-region. Structural considerations suggest that formation of the 1:1 complex requires a severe distortion of the lever-arm, potentially regulating functional motility. This would be consistent with a recent report of diverse, irregular shapes of the lever arm of myosin-V induced by the presence of Ca(2+).
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Affiliation(s)
- Stephen R Martin
- Division of Physical Biochemistry, National Institute for Medical Research, Mill Hill, London NW7 1AA, UK
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43
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Li XD, Mabuchi K, Ikebe R, Ikebe M. Ca2+-induced activation of ATPase activity of myosin Va is accompanied with a large conformational change. Biochem Biophys Res Commun 2004; 315:538-45. [PMID: 14975734 DOI: 10.1016/j.bbrc.2004.01.084] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2003] [Indexed: 11/30/2022]
Abstract
We succeeded in expressing the recombinant full-length myosin Va (M5Full) and studied its regulation mechanism. The actin-activated ATPase activity of M5Full was significantly activated by Ca(2+), whereas the truncated myosin Va without C-terminal globular domain is not regulated by Ca(2+) and constitutively active. Sedimentation analysis showed that the sedimentation coefficient of M5Full undergoes a Ca(2+)-induced conformational transition from 14S to 11S. Electron microscopy revealed that at low ionic strength, M5Full showed an extended conformation in high Ca(2+) while it formed a folded shape in the presence of EGTA, in which the tail domain was folded back towards the head-neck region. Furthermore, we found that the motor domain of myosin Va folds back to the neck domain in Ca(2+) while the head-neck domain is more extended in EGTA. It is thought that the association of the motor domain to the neck inhibits the binding of the tail to the neck thus destabilizing a folded conformation in Ca(2+). This conformational transition is closely correlated to the actin-activated ATPase activity. These results suggest that the tail and neck domain play a role in the Ca(2+) dependent regulation of myosin Va.
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Affiliation(s)
- Xiang-dong Li
- Department of Physiology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, MA 01655, USA
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44
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Krementsov DN, Krementsova EB, Trybus KM. Myosin V: regulation by calcium, calmodulin, and the tail domain. ACTA ACUST UNITED AC 2004; 164:877-86. [PMID: 15007063 PMCID: PMC2172279 DOI: 10.1083/jcb.200310065] [Citation(s) in RCA: 170] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Calcium activates the ATPase activity of tissue-purified myosin V, but not that of shorter expressed constructs. Here, we resolve this discrepancy by comparing an expressed full-length myosin V (dFull) to three shorter constructs. Only dFull has low ATPase activity in EGTA, and significantly higher activity in calcium. Based on hydrodynamic data and electron microscopic images, the inhibited state is due to a compact conformation that is possible only with the whole molecule. The paradoxical finding that dFull moved actin in EGTA suggests that binding of the molecule to the substratum turns it on, perhaps mimicking cargo activation. Calcium slows, but does not stop the rate of actin movement if excess calmodulin (CaM) is present. Without excess CaM, calcium binding to the high affinity sites dissociates CaM and stops motility. We propose that a folded-to-extended conformational change that is controlled by calcium and CaM, and probably by cargo binding itself, regulates myosin V's ability to transport cargo in the cell.
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Affiliation(s)
- Dimitry N Krementsov
- Dept. of Molecular Physiology and Biophysics, University of Vermont, 130 Health Science Research Facility, Burlington, VT 05405-0068, USA
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45
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Tompa P, Buzder-Lantos P, Tantos A, Farkas A, Szilágyi A, Bánóczi Z, Hudecz F, Friedrich P. On the sequential determinants of calpain cleavage. J Biol Chem 2004; 279:20775-85. [PMID: 14988399 DOI: 10.1074/jbc.m313873200] [Citation(s) in RCA: 251] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structural clues of substrate recognition by calpain are incompletely understood. In this study, 106 cleavage sites in substrate proteins compiled from the literature have been analyzed to dissect the signal for calpain cleavage and also to enable the design of an ideal calpain substrate and interfere with calpain action via site-directed mutagenesis. In general, our data underline the importance of the primary structure of the substrate around the scissile bond in the recognition process. Significant amino acid preferences were found to extend over 11 residues around the scissile bond, from P(4) to P(7)'. In compliance with earlier data, preferred residues in the P(2) position are Leu, Thr, and Val, and in P(1) Lys, Tyr, and Arg. In position P(1) ', small hydrophilic residues, Ser and to a lesser extent Thr and Ala, occur most often. Pro dominates the region flanking the P(2)-P(1)' segment, i.e. positions P(3) and P(2)'-P(4)'; most notable is its occurrence 5.59 times above chance in P(3)'. Intriguingly, the segment C-terminal to the cleavage site resembles the consensus inhibitory region of calpastatin, the specific inhibitor of the enzyme. Further, the position of the scissile bond correlates with certain sequential attributes, such as secondary structure and PEST score, which, along with the amino acid preferences, suggests that calpain cleaves within rather disordered segments of proteins. The amino acid preferences were confirmed by site-directed mutagenesis of the autolysis sites of Drosophila calpain B; when amino acids at key positions were changed to less preferred ones, autolytic cleavage shifted to other, adjacent sites. Based on these preferences, a new fluorogenic calpain substrate, DABCYLTPLKSPPPSPR-EDANS, was designed and synthesized. In the case of micro- and m-calpain, this substrate is kinetically superior to commercially available ones, and it can be used for the in vivo assessment of the activity of these ubiquitous mammalian calpains.
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Affiliation(s)
- Peter Tompa
- Institute of Enzymology, Biological Research Center, Hungarian Academy of Sciences, P.O. Box 7, H-1518 Budapest, Hungary
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46
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Tilelli CQ, Martins AR, Larson RE, Garcia-Cairasco N. Immunohistochemical localization of myosin Va in the adult rat brain. Neuroscience 2004; 121:573-86. [PMID: 14568019 DOI: 10.1016/s0306-4522(03)00546-3] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Brain myosin Va (MVa) is a molecular motor associated with plastic changes during development. MVa has previously been detected in the cell body and in dendrites of neuronal cells in culture, in cells of the guinea-pig cochlea, as well as in cerebellar cells. Adult Wistar rats (n=14), 250-300 g, were perfused with standard methods for immunohistochemistry, using a polyclonal, affinity-purified rabbit antibody against MVa tail domain. Anti-MVa antibody specifically stained neuronal nuclei from forebrain to cerebellar regions, and more intensely sensory nuclei. Differences in MVa immunoreactivity were detected between brain nuclei, ranging from very intense to weak staining. The analysis of MVa and glial fibrillary acidic protein staining in adjacent brain sections demonstrated a clear-cut neuronal labeling rather than an astroglial staining. The studies presented here represent a comprehensive map of MVa regional distribution in the CNS of the adult rat and may contribute to the basic understanding of its role in brain function and plasticity, particularly in relationship to phenomena that involve molecular motors, such as neurite outgrowth, organelle transport and neurotransmitter-vesicle cycling. It is important to highlight that this is a pioneer immunohistochemical study on the distribution of MVa on the whole brain of adult rats, a first step toward the understanding of its function in the CNS.
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Affiliation(s)
- C Q Tilelli
- Department of Physiology, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Av Bandeirantes, 3900, 14049-900 Ribeirão Preto, São Paulo, Brazil
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47
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Wang F, Thirumurugan K, Stafford WF, Hammer JA, Knight PJ, Sellers JR. Regulated conformation of myosin V. J Biol Chem 2003; 279:2333-6. [PMID: 14634000 DOI: 10.1074/jbc.c300488200] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We have found that myosin V, an important actin-based vesicle transporter, has a folded conformation that is coupled to inhibition of its enzymatic activity in the absence of cargo and Ca(2+). In the absence of Ca(2+) where the actin-activated MgATPase activity is low, purified brain myosin V sediments in the analytical ultracentrifuge at 14 S as opposed to 11 S in the presence of Ca(2+) where the activity is high. At high ionic strength it sediments at 10 S independent of Ca(2+), and its regulation is poor. These data are consistent with myosin V having a compact, inactive conformation in the absence of Ca(2+) and an extended conformation in the presence of Ca(2+) or high ionic strength. Electron microscopy reveals that in the absence of Ca(2+) the heads and tail are both folded to give a triangular shape, very different from the extended appearance of myosin V at high ionic strength. A recombinant myosin V heavy meromyosin fragment that is missing the distal portion of the tail domain is not regulated by calcium and has only a small change in sedimentation coefficient, which is in the opposite direction to that seen with intact myosin V. Electron microscopy shows that its heads are extended even in the absence of calcium. These data suggest that interaction between the motor and cargo binding domains may be a general mechanism for shutting down motor protein activity and thereby regulating the active movement of vesicles in cells.
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Affiliation(s)
- Fei Wang
- Laboratory of Molecular Cardiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, USA
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48
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Cao TT, Chang W, Masters SE, Mooseker MS. Myosin-Va binds to and mechanochemically couples microtubules to actin filaments. Mol Biol Cell 2003; 15:151-61. [PMID: 14565972 PMCID: PMC307536 DOI: 10.1091/mbc.e03-07-0504] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Myosin-Va was identified as a microtubule binding protein by cosedimentation analysis in the presence of microtubules. Native myosin-Va purified from chick brain, as well as the expressed globular tail domain of this myosin, but not head domain bound to microtubule-associated protein-free microtubules. Binding of myosin-Va to microtubules was saturable and of moderately high affinity (approximately 1:24 Myosin-Va:tubulin; Kd = 70 nM). Myosin-Va may bind to microtubules via its tail domain because microtubule-bound myosin-Va retained the ability to bind actin filaments resulting in the formation of cross-linked gels of microtubules and actin, as assessed by fluorescence and electron microscopy. In low Ca2+, ATP addition induced dissolution of these gels, but not release of myosin-Va from MTs. However, in 10 microM Ca2+, ATP addition resulted in the contraction of the gels into aster-like arrays. These results demonstrate that myosin-Va is a microtubule binding protein that cross-links and mechanochemically couples microtubules to actin filaments.
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Affiliation(s)
- Tracy T Cao
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA
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Casaletti L, Tauhata SBF, Moreira JE, Larson RE. Myosin-Va proteolysis by Ca2+/calpain in depolarized nerve endings from rat brain. Biochem Biophys Res Commun 2003; 308:159-64. [PMID: 12890495 DOI: 10.1016/s0006-291x(03)01350-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Myosin-Va is a molecular motor that may participate in synaptic vesicle cycling. Calpain cleaves myosin-Va in vitro at methionine 1141 in the tail domain. We show that intracellular proteolysis of myosin-Va occurs in rat cortical synaptosomes depolarized in the presence of calcium, evidenced by the formation of an 80 k polypeptide that co-migrates in SDS-PAGE with the 80 k fragment produced by the in vitro proteolysis of myosin-Va by calpain. Anti-myosin-Va antibody recognized this polypeptide in Western blots and immunoprecipitated it from synaptosome extracts. Calpastatin, a calpain-specific inhibitor, or leupeptin, a general cysteine protease inhibitor, suppressed or blocked formation of the 80 k polypeptide depending on membrane permeability. We conclude that myosin-Va undergoes intracellular proteolysis by endogenous calpain, when synaptosomes are depolarized in the presence of calcium, at the same cleavage site previously identified in vitro, thus, making it a target for calcium signaling during synaptic activation.
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Affiliation(s)
- Luciana Casaletti
- Department of Cellular and Molecular Biology, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, 14049-900 Ribeirão Preto, SP, Brazil
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Potter DA, Srirangam A, Fiacco KA, Brocks D, Hawes J, Herndon C, Maki M, Acheson D, Herman IM. Calpain regulates enterocyte brush border actin assembly and pathogenic Escherichia coli-mediated effacement. J Biol Chem 2003; 278:30403-12. [PMID: 12764139 PMCID: PMC2727654 DOI: 10.1074/jbc.m304616200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
This study identifies calpain as being instrumental for brush border (BB) microvillus assembly during differentiation and effacement during bacterial pathogenesis. Calpain activity is decreased by 25-80% in Caco 2 lines stably overexpressing calpastatin, the physiological inhibitor of calpain, and the effect is proportional to the calpastatin/calpain ratio. These lines exhibit a 2.5-fold reduction in the rate of microvillus extension. Apical microvillus assembly is reduced by up to 50%, as measured by quantitative fluorometric microscopy (QFM) of ezrin, indicating that calpain recruits ezrin to BB microvilli. Calpain inhibitors ZLLYCHN2, MDL 28170, and PD 150606 block BB assembly and ezrin recruitment to the BB. The HIV protease inhibitor ritonavir, which inhibits calpain at clinically relevant concentrations, also blocks BB assembly, whereas cathepsin and proteasome inhibitors do not. Microvillus effacement is inhibited after exposure of calpastatin-overexpressing cells to enteropathogenic Escherichia coli. These results suggest that calpain regulates BB assembly as well as pathological effacement, and indicate that it is an important regulator involved in HIV protease inhibitor toxicity and host-microbial pathogen interactions.
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Affiliation(s)
- David A. Potter
- Division of Hematology/Oncology, Walther Oncology Center and Veterans Affairs Medical Center, Indiana University, Indianapolis, Indiana 46202
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
- To whom correspondence may be addressed: Dept. of Medicine, Indiana University School of Medicine, 1044 W. Walnut St., Indianapolis, IN 46202-5254. Tel.: 317-274-2221; Fax: 317-274-0396; E-mail:
| | - Anjaiah Srirangam
- Division of Hematology/Oncology, Walther Oncology Center and Veterans Affairs Medical Center, Indiana University, Indianapolis, Indiana 46202
| | - Kerry A. Fiacco
- Division of Hematology/Oncology, Walther Oncology Center and Veterans Affairs Medical Center, Indiana University, Indianapolis, Indiana 46202
| | - Daniel Brocks
- Division of Hematology/Oncology, Walther Oncology Center and Veterans Affairs Medical Center, Indiana University, Indianapolis, Indiana 46202
| | - John Hawes
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Carter Herndon
- Department of Biochemistry and Molecular Biology, Indiana University, Indianapolis, Indiana 46202
| | - Masatoshi Maki
- Department of Molecular Applied Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan 464-01
| | - David Acheson
- Department of Public Health, University of Maryland, Baltimore, Maryland 21201
| | - Ira M. Herman
- Department of Physiology, Tufts University School of Medicine, Boston, Massachusetts 02111
- To whom correspondence may be addressed: Dept. of Physiology, Tufts University School of Medicine, 136 Harrison Ave., Boston, MA 02111. Tel.: 617-636-2991; Fax: 617-636-0445; E-mail:
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