1
|
Pan J, Zhou R, Yao LL, Zhang J, Zhang N, Cao QJ, Sun S, Li XD. Identification of a third myosin-5a-melanophilin interaction that mediates the association of myosin-5a with melanosomes. eLife 2024; 13:RP93662. [PMID: 38900147 PMCID: PMC11189624 DOI: 10.7554/elife.93662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
Transport and localization of melanosome at the periphery region of melanocyte are depended on myosin-5a (Myo5a), which associates with melanosome by interacting with its adaptor protein melanophilin (Mlph). Mlph contains four functional regions, including Rab27a-binding domain, Myo5a GTD-binding motif (GTBM), Myo5a exon F-binding domain (EFBD), and actin-binding domain (ABD). The association of Myo5a with Mlph is known to be mediated by two specific interactions: the interaction between the exon-F-encoded region of Myo5a and Mlph-EFBD and that between Myo5a-GTD and Mlph-GTBM. Here, we identify a third interaction between Myo5a and Mlph, that is, the interaction between the exon-G-encoded region of Myo5a and Mlph-ABD. The exon-G/ABD interaction is independent from the exon-F/EFBD interaction and is required for the association of Myo5a with melanosome. Moreover, we demonstrate that Mlph-ABD interacts with either the exon-G or actin filament, but cannot interact with both of them simultaneously. Based on above findings, we propose a new model for the Mlph-mediated Myo5a transportation of melanosomes.
Collapse
Affiliation(s)
- Jiabin Pan
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - Rui Zhou
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - 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 SciencesBeijingChina
| | - Jie 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 SciencesBeijingChina
| | - 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 SciencesBeijingChina
| | - Qing-Juan Cao
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
| | - Shaopeng Sun
- Group of Cell Motility and Muscle Contraction, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| | - 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 SciencesBeijingChina
- University of Chinese Academy of SciencesBeijingChina
| |
Collapse
|
2
|
Fineberg A, Takagi Y, Thirumurugan K, Andrecka J, Billington N, Young G, Cole D, Burgess SA, Curd AP, Hammer JA, Sellers JR, Kukura P, Knight PJ. Myosin-5 varies its step length to carry cargo straight along the irregular F-actin track. Proc Natl Acad Sci U S A 2024; 121:e2401625121. [PMID: 38507449 PMCID: PMC10990141 DOI: 10.1073/pnas.2401625121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 02/15/2024] [Indexed: 03/22/2024] Open
Abstract
Molecular motors employ chemical energy to generate unidirectional mechanical output against a track while navigating a chaotic cellular environment, potential disorder on the track, and against Brownian motion. Nevertheless, decades of nanometer-precise optical studies suggest that myosin-5a, one of the prototypical molecular motors, takes uniform steps spanning 13 subunits (36 nm) along its F-actin track. Here, we use high-resolution interferometric scattering microscopy to reveal that myosin takes strides spanning 22 to 34 actin subunits, despite walking straight along the helical actin filament. We show that cumulative angular disorder in F-actin accounts for the observed proportion of each stride length, akin to crossing a river on variably spaced stepping stones. Electron microscopy revealed the structure of the stepping molecule. Our results indicate that both motor and track are soft materials that can adapt to function in complex cellular conditions.
Collapse
Affiliation(s)
- Adam Fineberg
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, OxfordOX1 3QZ, United Kingdom
- Laboratory of Single Molecule Biophysics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD20892
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD20892
| | - Kavitha Thirumurugan
- Astbury Centre for Structural Molecular Biology, and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Joanna Andrecka
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, OxfordOX1 3QZ, United Kingdom
| | - Neil Billington
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD20892
| | - Gavin Young
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, OxfordOX1 3QZ, United Kingdom
| | - Daniel Cole
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, OxfordOX1 3QZ, United Kingdom
| | - Stan A. Burgess
- Astbury Centre for Structural Molecular Biology, and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - Alistair P. Curd
- Astbury Centre for Structural Molecular Biology, and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| | - John A. Hammer
- Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD20892
| | - James R. Sellers
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, MD20892
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, OxfordOX1 3QZ, United Kingdom
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, OxfordOX1 3QU, United Kingdom
| | - Peter J. Knight
- Astbury Centre for Structural Molecular Biology, and School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, LeedsLS2 9JT, United Kingdom
| |
Collapse
|
3
|
Li W, Li A, Yu B, Zhang X, Liu X, White KL, Stevens RC, Baumeister W, Sali A, Jasnin M, Sun L. In situ structure of actin remodeling during glucose-stimulated insulin secretion using cryo-electron tomography. Nat Commun 2024; 15:1311. [PMID: 38346988 PMCID: PMC10861521 DOI: 10.1038/s41467-024-45648-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 01/30/2024] [Indexed: 02/15/2024] Open
Abstract
Actin mediates insulin secretion in pancreatic β-cells through remodeling. Hampered by limited resolution, previous studies have offered an ambiguous depiction as depolymerization and repolymerization. We report the in situ structure of actin remodeling in INS-1E β-cells during glucose-stimulated insulin secretion at nanoscale resolution. After remodeling, the actin filament network at the cell periphery exhibits three marked differences: 12% of actin filaments reorient quasi-orthogonally to the ventral membrane; the filament network mainly remains as cell-stabilizing bundles but partially reconfigures into a less compact arrangement; actin filaments anchored to the ventral membrane reorganize from a "netlike" to a "blooming" architecture. Furthermore, the density of actin filaments and microtubules around insulin secretory granules decreases, while actin filaments and microtubules become more densely packed. The actin filament network after remodeling potentially precedes the transport and release of insulin secretory granules. These findings advance our understanding of actin remodeling and its role in glucose-stimulated insulin secretion.
Collapse
Affiliation(s)
- Weimin Li
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Angdi Li
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Bing Yu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaoxiao Zhang
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Xiaoyan Liu
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
| | - Kate L White
- Department of Chemistry, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, 90089, USA
| | - Raymond C Stevens
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China
- School of Life Science and Technology, ShanghaiTech University, Shanghai, 201210, China
| | - Wolfgang Baumeister
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China.
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152, Martinsried, Germany.
| | - Andrej Sali
- Quantitative Biosciences Institute, University of California, San Francisco, San Francisco, CA, 94158, USA.
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, 94158, USA.
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA, 94158, USA.
| | - Marion Jasnin
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, 85764, Neuherberg, Germany.
- Department of Chemistry, Technical University of Munich, 85748, Garching, Germany.
| | - Liping Sun
- iHuman Institute, ShanghaiTech University, Shanghai, 201210, China.
| |
Collapse
|
4
|
Gong R, Qin L, Chen L, Wang N, Bao Y, Lu W. Myosin Va-dependent Transport of NMDA Receptors in Hippocampal Neurons. Neurosci Bull 2024:10.1007/s12264-023-01174-y. [PMID: 38291290 DOI: 10.1007/s12264-023-01174-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 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.
Collapse
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.
| |
Collapse
|
5
|
Carew JA, Cristofaro V, Goyal RK, Sullivan MP. Differential Myosin 5a splice variants in innervation of pelvic organs. Front Physiol 2023; 14:1304537. [PMID: 38148903 PMCID: PMC10749955 DOI: 10.3389/fphys.2023.1304537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/20/2023] [Indexed: 12/28/2023] Open
Abstract
Introduction: Myosin proteins interact with filamentous actin and translate the chemical energy generated by ATP hydrolysis into a wide variety of mechanical functions in all cell types. The classic function of conventional myosins is mediation of muscle contraction, but myosins also participate in processes as diverse as exocytosis/endocytosis, membrane remodeling, and cytokinesis. Myosin 5a (Myo5a) is an unconventional motor protein well-suited to the processive transport of diverse molecular cargo within cells and interactions with multiprotein membrane complexes that facilitate exocytosis. Myo5a includes a region consisting of six small alternative exons which can undergo differential splicing. Neurons and skin melanocytes express characteristic splice variants of Myo5a, which are specialized for transport processes unique to those cell types. But less is known about the expression of Myo5a splice variants in other tissues, their cargos and interactive partners, and their regulation. Methods: In visceral organs, neurotransmission-induced contraction or relaxation of smooth muscle is mediated by Myo5a. Axons within urogenital organs and distal colon of rodents arise from cell bodies located in the major pelvic ganglion (MPG). However, in contrast to urogenital organs, the distal colon also contains soma of the enteric nervous system. Therefore, the rodent pelvic organs provide an opportunity to compare the expression of Myo5a splice variants, not only in different tissues innervated by the pelvic nerves, but also in different subcellular compartments of those nerves. This study examines the expression and distribution of Myo5a splice variants in the MPG, compared to the bladder, corpus cavernosum of the penis (CCP) and distal colon using immunohistochemistry and mRNA analyses. Results/discussion: We report detection of characteristic Myo5a variants in these tissues, with bladder and CCP displaying a similar variant pattern but one which differed from that of distal colon. In all three organs, Myo5a variants were distinct compared to the MPG, implying segregation of one variant within nerve soma and its exclusion from axons. The expression of distinct Myo5a variant arrays is likely to be adaptive, and to underlie specific functions fulfilled by Myo5a in those particular locations.
Collapse
Affiliation(s)
- Josephine A. Carew
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Medicine, Brigham and Women’s Hospital, Boston, MA, United States
| | - Vivian Cristofaro
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Surgery, Brigham and Women’s Hospital, Boston, MA, United States
| | - Raj K. Goyal
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
| | - Maryrose P. Sullivan
- Urology Research, VA Boston Healthcare System, Boston, MA, United States
- Harvard Medical School, Boston, MA, United States
- Department of Surgery, Brigham and Women’s Hospital, Boston, MA, United States
| |
Collapse
|
6
|
Fineberg A, Takagi Y, Thirumurugan K, Andrecka J, Billington N, Young G, Cole D, Burgess SA, Curd AP, Hammer JA, Sellers JR, Kukura P, Knight PJ. Myosin-5 varies its steps along the irregular F-actin track. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.16.549178. [PMID: 37503193 PMCID: PMC10370000 DOI: 10.1101/2023.07.16.549178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Molecular motors employ chemical energy to generate unidirectional mechanical output against a track. By contrast to the majority of macroscopic machines, they need to navigate a chaotic cellular environment, potential disorder in the track and Brownian motion. Nevertheless, decades of nanometer-precise optical studies suggest that myosin-5a, one of the prototypical molecular motors, takes uniform steps spanning 13 subunits (36 nm) along its F-actin track. Here, we use high-resolution interferometric scattering (iSCAT) microscopy to reveal that myosin takes strides spanning 22 to 34 actin subunits, despite walking straight along the helical actin filament. We show that cumulative angular disorder in F-actin accounts for the observed proportion of each stride length, akin to crossing a river on variably-spaced stepping stones. Electron microscopy revealed the structure of the stepping molecule. Our results indicate that both motor and track are soft materials that can adapt to function in complex cellular conditions.
Collapse
Affiliation(s)
- Adam Fineberg
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Laboratory of Single Molecule Biophysics, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Kavitha Thirumurugan
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
- Present address: Structural Biology Lab, Pearl Research Park, SBST, Vellore Institute of Technology, Vellore-632 014, India
| | - Joanna Andrecka
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Human Technopole, Viale Rita Levi-Montalcini 1, 20157, Milan, Italy
| | - Neil Billington
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
- Present address: Department of Biochemistry and Molecular Medicine, West Virginia University, Morgantown, WV, U.S.A
| | - Gavin Young
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Refeyn Ltd., Unit 9, Trade City, Sandy Ln W, Littlemore, Oxford OX4 6FF, U.K
| | - Daniel Cole
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- Present address: Refeyn Ltd., Unit 9, Trade City, Sandy Ln W, Littlemore, Oxford OX4 6FF, U.K
| | - Stan A. Burgess
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| | - Alistair P. Curd
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| | - John A. Hammer
- Cell and Developmental Biology Center, NHLBI, National Institutes of Health, Bethesda, MD 20892, U.S.A
| | - James R. Sellers
- Laboratory of Molecular Physiology, NHLBI, National Institutes of Health, Bethesda, Maryland 20892, U.S.A
| | - Philipp Kukura
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford OX1 3QZ, U.K
- The Kavli Institute for Nanoscience Discovery, Dorothy Crowfoot Hodgkin Building, University of Oxford, South Parks Rd, Oxford OX1 3QU, U.K
| | - Peter J. Knight
- Astbury Centre for Structural Molecular Biology, and Institute of Molecular and Cellular Biology, University of Leeds, Leeds, LS2 9JT, U.K
| |
Collapse
|
7
|
Niu F, Liu Y, Sun K, Xu S, Dong J, Yu C, Yan K, Wei Z. Autoinhibition and activation mechanisms revealed by the triangular-shaped structure of myosin Va. SCIENCE ADVANCES 2022; 8:eadd4187. [PMID: 36490350 PMCID: PMC9733927 DOI: 10.1126/sciadv.add4187] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 11/03/2022] [Indexed: 06/17/2023]
Abstract
As the prototype of unconventional myosin motor family, myosin Va (MyoVa) transport cellular cargos along actin filaments in diverse cellular processes. The off-duty MyoVa adopts a closed and autoinhibited state, which can be relieved by cargo binding. The molecular mechanisms governing the autoinhibition and activation of MyoVa remain unclear. Here, we report the cryo-electron microscopy structure of the two full-length, closed MyoVa heavy chains in complex with 12 calmodulin light chains at 4.78-Å resolution. The MyoVa adopts a triangular structure with multiple intra- and interpolypeptide chain interactions in establishing the closed state with cargo binding and adenosine triphosphatase activity inhibited. Structural, biochemical, and cellular analyses uncover an asymmetric autoinhibition mechanism, in which the cargo-binding sites in the two MyoVa heavy chains are differently protected. Thus, specific and efficient MyoVa activation requires coincident binding of multiple cargo adaptors, revealing an intricate and elegant activity regulation of the motor in response to cargos.
Collapse
Affiliation(s)
- Fengfeng Niu
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Yong Liu
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- SUSTech-HIT Joint PhD Program, Harbin Institute of Technology, Harbin, Heilongjiang, China
| | - Kang Sun
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Shun Xu
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Jiayuan Dong
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Cong Yu
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China
| | - Kaige Yan
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Zhiyi Wei
- Brain Research Center, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen, Guangdong, China
| |
Collapse
|
8
|
Weijman JF, Yadav SKN, Surridge KJ, Cross JA, Borucu U, Mantell J, Woolfson DN, Schaffitzel C, Dodding MP. Molecular architecture of the autoinhibited kinesin-1 lambda particle. SCIENCE ADVANCES 2022; 8:eabp9660. [PMID: 36112680 PMCID: PMC9481135 DOI: 10.1126/sciadv.abp9660] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Accepted: 07/29/2022] [Indexed: 06/15/2023]
Abstract
Despite continuing progress in kinesin enzyme mechanochemistry and emerging understanding of the cargo recognition machinery, it is not known how these functions are coupled and controlled by the α-helical coiled coils encoded by a large component of kinesin protein sequences. Here, we combine computational structure prediction with single-particle negative-stain electron microscopy to reveal the coiled-coil architecture of heterotetrameric kinesin-1 in its compact state. An unusual flexion in the scaffold enables folding of the complex, bringing the kinesin heavy chain-light chain interface into close apposition with a tetrameric assembly formed from the region of the molecule previously assumed to be the folding hinge. This framework for autoinhibition is required to uncover how engagement of cargo and other regulatory factors drives kinesin-1 activation.
Collapse
Affiliation(s)
- Johannes F. Weijman
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Sathish K. N. Yadav
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Katherine J. Surridge
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Jessica A. Cross
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, UK
| | - Ufuk Borucu
- GW4 Facility for High-Resolution Electron Cryo-Microscopy, University of Bristol, Bristol, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
| | - Derek N. Woolfson
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Christiane Schaffitzel
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Mark P. Dodding
- School of Biochemistry, University of Bristol, Biomedical Sciences Building, University Walk, Bristol BS8 1TD, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| |
Collapse
|
9
|
McMillan SN, Scarff CA. Cryo-electron microscopy analysis of myosin at work and at rest. Curr Opin Struct Biol 2022; 75:102391. [DOI: 10.1016/j.sbi.2022.102391] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 04/18/2022] [Accepted: 04/22/2022] [Indexed: 01/01/2023]
|
10
|
Haraguchi T, Ito K, Morikawa T, Yoshimura K, Shoji N, Kimura A, Iwaki M, Tominaga M. Autoregulation and dual stepping mode of MYA2, an Arabidopsis myosin XI responsible for cytoplasmic streaming. Sci Rep 2022; 12:3150. [PMID: 35210477 PMCID: PMC8873201 DOI: 10.1038/s41598-022-07047-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 02/08/2022] [Indexed: 11/09/2022] Open
Abstract
Arabidopsis thaliana has 13 genes belonging to the myosin XI family. Myosin XI-2 (MYA2) plays a major role in the generation of cytoplasmic streaming in Arabidopsis cells. In this study, we investigated the molecular properties of MYA2 expressed by the baculovirus transfer system. Actin-activated ATPase activity and in vitro motility assays revealed that activity of MYA2 was regulated by the globular tail domain (GTD). When the GTD is not bound to the cargo, the GTD inhibits ADP dissociation from the motor domain. Optical nanometry of single MYA2 molecules, combining total internal reflection fluorescence microscopy (TIRFM) and the fluorescence imaging with one-nanometer accuracy (FIONA) method, revealed that the MYA2 processively moved on actin with three different step sizes: − 28 nm, 29 nm, and 60 nm, at low ATP concentrations. This result indicates that MYA2 uses two different stepping modes; hand-over-hand and inchworm-like. Force measurement using optical trapping showed the stall force of MYA2 was 0.85 pN, which was less than half that of myosin V (2–3 pN). These results indicated that MYA2 has different transport properties from that of the myosin V responsible for vesicle transport in animal cells. Such properties may enable multiple myosin XIs to transport organelles quickly and smoothly, for the generation of cytoplasmic streaming in plant cells.
Collapse
Affiliation(s)
- Takeshi Haraguchi
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
| | - Kohji Ito
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan.
| | | | - Kohei Yoshimura
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
| | - Nao Shoji
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
| | - Atsushi Kimura
- Department of Biology, Graduate School of Science, Chiba University, Chiba, 263-8522, Japan
| | - Mitsuhiro Iwaki
- RIKEN Center for Biosystems Dynamics Research, RIKEN, Osaka, Japan.
| | - Motoki Tominaga
- Faculty of Education and Integrated Arts and Sciences, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan. .,Major in Integrative Bioscience and Biomedical Engineering, Graduate School of Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan.
| |
Collapse
|
11
|
Arabidopsis thaliana myosin XIK is recruited to the Golgi through interaction with a MyoB receptor. Commun Biol 2021; 4:1182. [PMID: 34645991 PMCID: PMC8514473 DOI: 10.1038/s42003-021-02700-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 08/31/2021] [Indexed: 12/03/2022] Open
Abstract
Plant cell organelles are highly mobile and their positioning play key roles in plant growth, development and responses to changing environmental conditions. Movement is acto-myosin dependent. Despite controlling the dynamics of several organelles, myosin and myosin receptors identified so far in Arabidopsis thaliana generally do not localise to the organelles whose movement they control, raising the issue of how specificity is determined. Here we show that a MyoB myosin receptor, MRF7, specifically localises to the Golgi membrane and affects its movement. Myosin XI-K was identified as a putative MRF7 interactor through mass spectrometry analysis. Co-expression of MRF7 and XI-K tail triggers the relocation of XI-K to the Golgi, linking a MyoB/myosin complex to a specific organelle in Arabidopsis. FRET-FLIM confirmed the in vivo interaction between MRF7 and XI-K tail on the Golgi and in the cytosol, suggesting that myosin/myosin receptor complexes perhaps cycle on and off organelle membranes. This work supports a traditional mechanism for organelle movement where myosins bind to receptors and adaptors on the organelle membranes, allowing them to actively move on the actin cytoskeleton, rather than passively in the recently proposed cytoplasmic streaming model. Perico et al. use co-expression analysis and a FRET-FLIM approach to show that the Arabidopsis MyoB myosin receptor, MRF7, triggers the relocation of Myosin XI-K to the Golgi. As such, this study provides evidence for plant myosin recruitment and control of organelle movement.
Collapse
|
12
|
Zea DJ, Laskina S, Baudin A, Richard H, Laine E. Assessing conservation of alternative splicing with evolutionary splicing graphs. Genome Res 2021; 31:1462-1473. [PMID: 34266979 PMCID: PMC8327911 DOI: 10.1101/gr.274696.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Accepted: 06/11/2021] [Indexed: 12/29/2022]
Abstract
Understanding how protein function has evolved and diversified is of great importance for human genetics and medicine. Here, we tackle the problem of describing the whole transcript variability observed in several species by generalizing the definition of splicing graph. We provide a practical solution to construct parsimonious evolutionary splicing graphs where each node is a minimal transcript building block defined across species. We show a clear link between the functional relevance, tissue regulation, and conservation of alternative transcripts on a set of 50 genes. By scaling up to the whole human protein-coding genome, we identify a few thousand genes where alternative splicing modulates the number and composition of pseudorepeats. We have implemented our approach in ThorAxe, an efficient, versatile, robust, and freely available computational tool.
Collapse
Affiliation(s)
- Diego Javier Zea
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| | - Sofya Laskina
- Bioinformatics Unit (MF1), Department for Methods Development and Research Infrastructure, Robert Koch Institute, 13353 Berlin, Germany
| | - Alexis Baudin
- Sorbonne Université, CNRS, LIP6, F-75005 Paris, France
| | - Hugues Richard
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
- Bioinformatics Unit (MF1), Department for Methods Development and Research Infrastructure, Robert Koch Institute, 13353 Berlin, Germany
| | - Elodie Laine
- Sorbonne Université, CNRS, IBPS, Laboratoire de Biologie Computationnelle et Quantitative (LCQB), 75005 Paris, France
| |
Collapse
|
13
|
Zhang H, Wu Z, Yang L, Zhang Z, Chen H, Ren J. Novel mutations in the Myo5a gene cause a dilute coat color phenotype in mice. FASEB J 2021; 35:e21261. [PMID: 33715225 DOI: 10.1096/fj.201903141rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 11/13/2020] [Accepted: 11/25/2020] [Indexed: 11/11/2022]
Abstract
C57BL/6 laboratory mice usually show black coat color. We observed a dilute (gray) coat color phenotype in progenies of two C57BL/6 mice. This phenotype is inherited in an autosomal recessive mode. To uncover the molecular mechanism underlying this naturally occurring phenotypic variation, we performed whole-genome sequencing (25×) on 10 offspring of the two founder mice. The whole-genome DNA sequencing and additional RNA-Seq data reveal that Myo5a is the gene responsible for the coat color dilution in C57BL/6 mice, and novel mutations in the Myo5a gene are likely causal. We further performed reverse transcription-quantitative PCR, and showed increased expression of truncated Myo5a transcripts encoding dysfunctional proteins and decreased expression of Myo5a full-length transcripts encoding functional proteins in mutant individuals. The decrease in full-length messenger RNA abundance was accompanied by reduced Myo5a protein level and deficient melanosome transport, a potential mechanistic link between the Myo5a mutations and the dilute color phenotype. This study not only advances our understanding of the molecular mechanisms of pigmentation in mice, but also provides a typical case of deciphering the molecular basis of phenotypic variation in mice by genomic analyses and subsequent functional work.
Collapse
Affiliation(s)
- Hui Zhang
- College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhongping Wu
- College of Animal Science and Technology, Zhongkai University of Agriculture and Engineering, Guangzhou, China
| | - Lijuan Yang
- College of Animal Science, South China Agricultural University, Guangzhou, China
| | - Zhen Zhang
- College of Biotechnology, Guilin Medical University, Guilin, China
| | - Hao Chen
- College of Life Science, Jiangxi Science and Technology Normal University, Nanchang, China
| | - Jun Ren
- College of Animal Science, South China Agricultural University, Guangzhou, China
| |
Collapse
|
14
|
Rivas S, Hanif K, Chakouri N, Ben-Johny M. Probing ion channel macromolecular interactions using fluorescence resonance energy transfer. Methods Enzymol 2021; 653:319-347. [PMID: 34099178 DOI: 10.1016/bs.mie.2021.01.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ion channels are macromolecular complexes whose functions are exquisitely tuned by interacting proteins. Fluorescence resonance energy transfer (FRET) is a powerful methodology that is adept at quantifying ion channel protein-protein interactions in living cells. For FRET experiments, the interacting partners are tagged with appropriate donor and acceptor fluorescent proteins. If the fluorescently-labeled molecules are in close proximity, then photoexcitation of the donor results in non-radiative energy transfer to the acceptor, and subsequent fluorescence emission of the acceptor. The stoichiometry of ion channel interactions and their relative binding affinities can be deduced by quantifying both the FRET efficiency and the total number of donors and acceptors in a given cell. In this chapter, we discuss general considerations for FRET analysis of biological interactions, various strategies for estimating FRET efficiencies, and detailed protocols for construction of binding curves and determination of stoichiometry. We focus on implementation of FRET assays using a flow cytometer given its amenability for high-throughput data acquisition, enhanced accessibility, and robust analysis. This versatile methodology permits mechanistic dissection of dynamic changes in ion channel interactions.
Collapse
Affiliation(s)
- Sharen Rivas
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, United States
| | | | - Nourdine Chakouri
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, United States
| | - Manu Ben-Johny
- Department of Physiology and Cellular Biophysics, Columbia University, New York, NY, United States.
| |
Collapse
|
15
|
Abstract
Since the discovery of muscle in the 19th century, myosins as molecular motors have been extensively studied. However, in the last decade, a new functional super-relaxed (SRX) state of myosin has been discovered, which has a 10-fold slower ATP turnover rate than the already-known non-actin-bound, disordered relaxed (DRX) state. These two states are in dynamic equilibrium under resting muscle conditions and are thought to be significant contributors to adaptive thermogenesis in skeletal muscle and can act as a reserve pool that may be recruited when there is a sustained demand for increased cardiac muscle power. This report provides an evolutionary perspective of how striated muscle contraction is regulated by modulating this myosin DRX↔SRX state equilibrium. We further discuss this equilibrium with respect to different physiological and pathophysiological perturbations, including insults causing hypertrophic cardiomyopathy, and small-molecule effectors that modulate muscle contractility in diseased pathology.
Collapse
Affiliation(s)
- Suman Nag
- Department of Biology, MyoKardia IncBrisbaneUnited States
| | - Darshan V Trivedi
- Department of Biochemistry, Stanford University School of MedicineStanfordUnited States
| |
Collapse
|
16
|
Wong S, Weisman LS. Roles and regulation of myosin V interaction with cargo. Adv Biol Regul 2021; 79:100787. [PMID: 33541831 PMCID: PMC7920922 DOI: 10.1016/j.jbior.2021.100787] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Accepted: 01/11/2021] [Indexed: 05/08/2023]
Abstract
A major question in cell biology is, how are organelles and large macromolecular complexes transported within a cell? Myosin V molecular motors play critical roles in the distribution of organelles, vesicles, and mRNA. Mis-localization of organelles that depend on myosin V motors underlie diseases in the skin, gut, and brain. Thus, the delivery of organelles to their proper destination is important for animal physiology and cellular function. Cargoes attach to myosin V motors via cargo specific adaptor proteins, which transiently bridge motors to their cargoes. Regulation of these adaptor proteins play key roles in the regulation of cargo transport. Emerging studies reveal that cargo adaptors play additional essential roles in the activation of myosin V, and the regulation of actin filaments. Here, we review how motor-adaptor interactions are controlled to regulate the proper loading and unloading of cargoes, as well as roles of adaptor proteins in the regulation of myosin V activity and the dynamics of actin filaments.
Collapse
Affiliation(s)
- Sara Wong
- Cell and Molecular Biology, University of Michigan, Ann Arbor, United States; Life Sciences Institute, University of Michigan, Ann Arbor, United States
| | - Lois S Weisman
- Cell and Developmental Biology, University of Michigan, Ann Arbor, United States; Life Sciences Institute, University of Michigan, Ann Arbor, United States.
| |
Collapse
|
17
|
Niu F, Sun K, Wei W, Yu C, Wei Z. F-actin disassembly factor MICAL1 binding to Myosin Va mediates cargo unloading during cytokinesis. SCIENCE ADVANCES 2020; 6:6/45/eabb1307. [PMID: 33158857 PMCID: PMC7673715 DOI: 10.1126/sciadv.abb1307] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2020] [Accepted: 09/25/2020] [Indexed: 05/08/2023]
Abstract
Motor-mediated intracellular trafficking requires motors to position cargoes at proper locations. Myosin Va (MyoVa), an actin-based motor, is a classic model for studying cargo transport. However, the molecular basis underlying cargo unloading in MyoVa-mediated transport has remained enigmatic. We have identified MICAL1, an F-actin disassembly regulator, as a binding partner of MyoVa and shown that MICAL1-MyoVa interaction is critical for localization of MyoVa at the midbody. By binding to MICAL1, MyoVa-mediated transport is terminated, resulting in vesicle unloading at the midbody for efficient cytokinesis. The MyoVa/MICAL1 complex structure reveals that MICAL1 and F-actin assembly factors, Spires, share an overlapped binding surface on MyoVa, suggesting a regulatory role of F-actin dynamics in cargo unloading. Down-regulating F-actin disassembly by a MICAL1 mutant significantly reduces MyoVa and vesicles accumulating at the midbody. Collectively, our findings demonstrate that MyoVa binds to MICAL1 at the midbody destination and triggers F-actin disassembly to unload the vesicle cargo.
Collapse
Affiliation(s)
- Fengfeng Niu
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Kang Sun
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China
| | - Wenjie Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China
- Core Research Facilities, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Cong Yu
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China.
- Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, and Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, Guangdong, China
| | - Zhiyi Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong, China.
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, Guangdong, China
| |
Collapse
|
18
|
Abstract
Myosins constitute a superfamily of actin-based molecular motor proteins that mediates a variety of cellular activities including muscle contraction, cell migration, intracellular transport, the formation of membrane projections, cell adhesion, and cell signaling. The 12 myosin classes that are expressed in humans share sequence similarities especially in the N-terminal motor domain; however, their enzymatic activities, regulation, ability to dimerize, binding partners, and cellular functions differ. It is becoming increasingly apparent that defects in myosins are associated with diseases including cardiomyopathies, colitis, glomerulosclerosis, neurological defects, cancer, blindness, and deafness. Here, we review the current state of knowledge regarding myosins and disease.
Collapse
|
19
|
Szikora S, Gajdos T, Novák T, Farkas D, Földi I, Lenart P, Erdélyi M, Mihály J. Nanoscopy reveals the layered organization of the sarcomeric H-zone and I-band complexes. J Cell Biol 2020; 219:132617. [PMID: 31816054 PMCID: PMC7039190 DOI: 10.1083/jcb.201907026] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2019] [Revised: 10/04/2019] [Accepted: 10/22/2019] [Indexed: 01/18/2023] Open
Abstract
Sarcomeres are extremely highly ordered macromolecular assemblies where structural organization is intimately linked to their functionality as contractile units. Although the structural basis of actin and Myosin interaction is revealed at a quasiatomic resolution, much less is known about the molecular organization of the I-band and H-zone. We report the development of a powerful nanoscopic approach, combined with a structure-averaging algorithm, that allowed us to determine the position of 27 sarcomeric proteins in Drosophila melanogaster flight muscles with a quasimolecular, ∼5- to 10-nm localization precision. With this protein localization atlas and template-based protein structure modeling, we have assembled refined I-band and H-zone models with unparalleled scope and resolution. In addition, we found that actin regulatory proteins of the H-zone are organized into two distinct layers, suggesting that the major place of thin filament assembly is an M-line-centered narrow domain where short actin oligomers can form and subsequently anneal to the pointed end.
Collapse
Affiliation(s)
- Szilárd Szikora
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Tamás Gajdos
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Tibor Novák
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - Dávid Farkas
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Doctoral School in Biology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - István Földi
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary
| | - Peter Lenart
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Miklós Erdélyi
- Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| | - József Mihály
- Institute of Genetics, Biological Research Centre, Hungarian Academy of Sciences, Szeged, Hungary.,Department of Optics and Quantum Electronics, University of Szeged, Szeged, Hungary
| |
Collapse
|
20
|
Kodera N, Ando T. High-Speed Atomic Force Microscopy to Study Myosin Motility. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1239:127-152. [PMID: 32451858 DOI: 10.1007/978-3-030-38062-5_7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
High-speed atomic force microscopy (HS-AFM) is a unique tool that enables imaging of protein molecules during their functional activity at sub-100 ms temporal and submolecular spatial resolution. HS-AFM is suited for the study of highly dynamic proteins, including myosin motors. HS-AFM images of myosin V walking on actin filaments provide irrefutable evidence for the swinging lever arm motion propelling the molecule forward. Moreover, molecular behaviors that have not been noticed before are also displayed on the AFM movies. This chapter describes the principle, underlying techniques and performance of HS-AFM, filmed images of myosin V, and mechanistic insights into myosin motility provided from the filmed images.
Collapse
Affiliation(s)
- Noriyuki Kodera
- Nano Life Science Institute (WPI NanoLSI), Kanazawa University, Kanazawa, Japan
| | - Toshio Ando
- Nano Life Science Institute (WPI NanoLSI), Kanazawa University, Kanazawa, Japan.
| |
Collapse
|
21
|
Ren W, Liu N, Hou Y, Li B, Zhou M, Chen C. Characterization of the Resistance Mechanism and Risk of Fusarium verticillioides to the Myosin Inhibitor Phenamacril. PHYTOPATHOLOGY 2020; 110:790-794. [PMID: 31961255 DOI: 10.1094/phyto-11-19-0407-r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Fusarium verticillioides is a major pathogen of maize that causes ear rot and produces mycotoxins. Phenamacril is a novel cyanoacrylate fungicide that exhibits favorable activity against Fusarium species. In this study, the phenamacril-resistant mutants of F. verticillioides were obtained by ultraviolet mutagenesis. Single point mutations of S73L or E276K in the myosin-1 FvMyo1 were proven to be responsible for the high-level resistance of F. verticillioides to phenamacril. Phenamacril had a significant impact on the localization of the wild-type FvMyo1 (FvMyo1WT-green fluorescent protein [GFP]), but not on the mutated FvMyo1 (FvMyo1S73L-GFP and FvMyo1E276K-GFP) at the hyphal tips. Molecular docking analysis suggested that mutation (S73L or E276K) in FvMyo1 altered the binding mode and decreased the binding affinity between phenamacril and myosin-1. There was no significant fitness penalty in mycelial growth, conidiation, and virulence of F. verticillioides associated with resistance to phenamacril. The results will enhance our understanding of the resistance mechanism of F. verticillioides to phenamacril and provide new reference data for the management of maize ear rot.
Collapse
Affiliation(s)
- Weichao Ren
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Na Liu
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Yiping Hou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Baohua Li
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, Shandong, China
| | - Mingguo Zhou
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| | - Changjun Chen
- College of Plant Protection, Nanjing Agricultural University, Nanjing, Jiangsu, China
| |
Collapse
|
22
|
Lu W, Lakonishok M, Liu R, Billington N, Rich A, Glotzer M, Sellers JR, Gelfand VI. Competition between kinesin-1 and myosin-V defines Drosophila posterior determination. eLife 2020; 9:54216. [PMID: 32057294 PMCID: PMC7112953 DOI: 10.7554/elife.54216] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 02/14/2020] [Indexed: 12/05/2022] Open
Abstract
Local accumulation of oskar (osk) mRNA in the Drosophila oocyte determines the posterior pole of the future embryo. Two major cytoskeletal components, microtubules and actin filaments, together with a microtubule motor, kinesin-1, and an actin motor, myosin-V, are essential for osk mRNA posterior localization. In this study, we use Staufen, an RNA-binding protein that colocalizes with osk mRNA, as a proxy for osk mRNA. We demonstrate that posterior localization of osk/Staufen is determined by competition between kinesin-1 and myosin-V. While kinesin-1 removes osk/Staufen from the cortex along microtubules, myosin-V anchors osk/Staufen at the cortex. Myosin-V wins over kinesin-1 at the posterior pole due to low microtubule density at this site, while kinesin-1 wins at anterior and lateral positions because they have high density of cortically-anchored microtubules. As a result, posterior determinants are removed from the anterior and lateral cortex but retained at the posterior pole. Thus, posterior determination of Drosophila oocytes is defined by kinesin-myosin competition, whose outcome is primarily determined by cortical microtubule density. One of the most fundamental steps of embryonic development is deciding which end of the body should be the head, and which should be the tail. Known as 'axis specification', this process depends on the location of genetic material called mRNAs. In fruit flies, for example, the tail-end of the embryo accumulates an mRNA called oskar. If this mRNA is missing, the embryo will not develop an abdomen. The build-up of oskar mRNA happens before the egg is even fertilized and depends on two types of scaffold proteins in the egg cell called microtubules and microfilaments. These scaffolds act like ‘train tracks’ in the cell and have associated protein motors, which work a bit like trains, carrying cargo as they travel up and down along the scaffolds. For microtubules, one of the motors is a protein called kinesin-1, whereas for microfilaments, the motors are called myosins. Most microtubules in the egg cell are pointing away from the membrane, while microfilament tracks form a dense network of randomly oriented filaments just underneath the membrane. It was already known that kinesin-1 and a myosin called myosin-V are important for localizing oskar mRNA to the posterior of the egg. However, it was not clear why the mRNA only builds up in that area. To find out, Lu et al. used a probe to track oskar mRNA, while genetically manipulating each of the motors so that their ability to transport cargo changed. Modulating the balance of activity between the two motors revealed that kinesin-1 and myosin-V engage in a tug-of-war inside the egg: myosin-V tries to keep oskar mRNA underneath the membrane of the cell, while kinesin-1 tries to pull it away from the membrane along microtubules. The winner of this molecular battle depends on the number of microtubule tracks available in the local area of the cell. In most parts of the cell, there are abundant microtubules, so kinesin-1 wins and pulls oskar mRNA away from the membrane. But at the posterior end of the cell there are fewer microtubules, so myosin-V wins, allowing oskar mRNA to localize in this area. Artificially 'shaving' some microtubules in a local area immediately changed the outcome of this tug-of-war creating a build-up of oskar mRNA in the 'shaved' patch. This is the first time a molecular tug-of-war has been shown in an egg cell, but in other types of cell, such as neurons and pigment cells, myosins compete with kinesins to position other molecular cargoes. Understanding these processes more clearly sheds light not only on embryo development, but also on cell biology in general.
Collapse
Affiliation(s)
- Wen Lu
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Margot Lakonishok
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| | - Rong Liu
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Neil Billington
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Ashley Rich
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, United States
| | - Michael Glotzer
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, United States
| | - James R Sellers
- Cell Biology and Physiology Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, United States
| | - Vladimir I Gelfand
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, United States
| |
Collapse
|
23
|
Sellers JR, Takagi Y. How Myosin 5 Walks Deduced from Single-Molecule Biophysical Approaches. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1239:153-181. [PMID: 32451859 DOI: 10.1007/978-3-030-38062-5_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Myosin 5a is a two-headed myosin that functions as a cargo transporter in cells. To accomplish this task it has evolved several unique structural and kinetic features that allow it to move processively as a single molecule along actin filaments. A plethora of biophysical techniques have been used to elucidate the detailed mechanism of its movement along actin filaments in vitro. This chapter describes how this mechanism was deduced.
Collapse
Affiliation(s)
- James R Sellers
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
| | - Yasuharu Takagi
- Laboratory of Molecular Physiology, Cell and Developmental Biology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
24
|
Unconventional Myosins: How Regulation Meets Function. Int J Mol Sci 2019; 21:ijms21010067. [PMID: 31861842 PMCID: PMC6981383 DOI: 10.3390/ijms21010067] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 12/16/2019] [Accepted: 12/18/2019] [Indexed: 01/24/2023] Open
Abstract
Unconventional myosins are multi-potent molecular motors that are assigned important roles in fundamental cellular processes. Depending on their mechano-enzymatic properties and structural features, myosins fulfil their roles by acting as cargo transporters along the actin cytoskeleton, molecular anchors or tension sensors. In order to perform such a wide range of roles and modes of action, myosins need to be under tight regulation in time and space. This is achieved at multiple levels through diverse regulatory mechanisms: the alternative splicing of various isoforms, the interaction with their binding partners, their phosphorylation, their applied load and the composition of their local environment, such as ions and lipids. This review summarizes our current knowledge of how unconventional myosins are regulated, how these regulatory mechanisms can adapt to the specific features of a myosin and how they can converge with each other in order to ensure the required tight control of their function.
Collapse
|
25
|
Myosin Va and spermine synthase: partners in exosome transport. Biosci Rep 2019; 39:BSR20190326. [PMID: 30967493 PMCID: PMC6488853 DOI: 10.1042/bsr20190326] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 11/21/2022] Open
Abstract
A recent paper in Bioscience Reports (BSR20182189) describes the discovery of an
interaction between the motor protein myosin Va and the metabolic enzyme
spermine synthase. Myosin Va is a molecular motor which plays a key role in
vesicle transport. Mutations in the gene which encodes this protein are
associated with Griscelli syndrome type 1 and the ‘dilute’
phenotype in animals. Spermine synthase catalyzes the conversion of spermidine
to spermine. This largely cytoplasmic enzyme can also be localized to the
soluble fraction in exosomes. Mutations in the spermine synthase gene are
associated with Snyder Robinson mental retardation syndrome. The interaction
between the two proteins was detected using the yeast two hybrid method and
verified by microscale thermophoresis of recombinant proteins. Knockdown of the
MYO5A gene reduced the expression of mRNA coding for
spermine synthase. The amount of this transcript was also reduced in cells
derived from a patient with Griscelli syndrome type 1. This suggests that, in
addition to a direct physical interaction between the two proteins, myosin Va
also modulates the transcription of the spermine synthase gene. The mechanism
for this modulation is currently unknown. These findings have implications for
Griscelli syndrome type 1 and Snyder Robinson mental retardation syndrome. They
also suggest that interactions between myosin Va and soluble exosome proteins
such as spermine synthase may be important in the mechanism of exosome
transport.
Collapse
|
26
|
Tang K, Li Y, Yu C, Wei Z. Structural mechanism for versatile cargo recognition by the yeast class V myosin Myo2. J Biol Chem 2019; 294:5896-5906. [PMID: 30804213 PMCID: PMC6463705 DOI: 10.1074/jbc.ra119.007550] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 02/14/2019] [Indexed: 01/07/2023] Open
Abstract
Class V myosins are actin-dependent motors, which recognize numerous cellular cargos mainly via the C-terminal globular tail domain (GTD). Myo2, a yeast class V myosin, can transport a broad range of organelles. However, little is known about the capacity of Myo2-GTD to recognize such a diverse array of cargos specifically at the molecular level. Here, we solved crystal structures of Myo2-GTD (at 1.9-3.1 Å resolutions) in complex with three cargo adaptor proteins: Smy1 (for polarization of secretory vesicles), Inp2 (for peroxisome transport), and Mmr1 (for mitochondria transport). The structures of Smy1- and Inp2-bound Myo2-GTD, along with site-directed mutagenesis experiments, revealed a binding site in subdomain-I having a hydrophobic groove with high flexibility enabling Myo2-GTD to accommodate different protein sequences. The Myo2-GTD-Mmr1 complex structure confirmed and complemented a previously identified mitochondrion/vacuole-specific binding region. Moreover, differences between the conformations and locations of cargo-binding sites identified here for Myo2 and those reported for mammalian MyoVA (MyoVA) suggest that class V myosins potentially have co-evolved with their specific cargos. Our structural and biochemical analysis not only uncovers a molecular mechanism that explains the diverse cargo recognition by Myo2-GTD, but also provides structural information useful for future functional studies of class V myosins in cargo transport.
Collapse
Affiliation(s)
- Kun Tang
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055 and , To whom correspondence may be addressed. E-mail:
| | - Yujie Li
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055 and
| | - Cong Yu
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055 and ,the Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research, Shenzhen Key Laboratory of Cell Microenvironment, Shenzhen, China 518055
| | - Zhiyi Wei
- From the Department of Biology, Southern University of Science and Technology, Shenzhen 518055 and , Member of the Neural and Cognitive Sciences Research Center, SUSTech. To whom correspondence may be addressed. Tel.:
86-88018411; E-mail:
| |
Collapse
|
27
|
Kodera N, Ando T. Direct Imaging of Walking Myosin V by High-Speed Atomic Force Microscopy. Methods Mol Biol 2019; 1805:103-122. [PMID: 29971715 DOI: 10.1007/978-1-4939-8556-2_6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
High-speed atomic force microscopy allows for directly observing biological molecules in dynamic action at submolecular and sub-100 ms spatiotemporal resolution, without disturbing their function. This microscopy has recently been applied to various proteins with great success. Here, we describe methods to image myosin V molecules walking on actin filaments with high-speed atomic force microscopy.
Collapse
Affiliation(s)
- Noriyuki Kodera
- Nano Life Science Institute (WPI NanoLSI), Kanazawa University, Kanazawa, Japan
| | - Toshio Ando
- Nano Life Science Institute (WPI NanoLSI), Kanazawa University, Kanazawa, Japan.
| |
Collapse
|
28
|
Regulation of Myosin-5b by Rab11a and the Rab11 family interacting protein 2. Biosci Rep 2019; 39:BSR20181252. [PMID: 30545898 PMCID: PMC6328864 DOI: 10.1042/bsr20181252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 12/06/2018] [Accepted: 12/12/2018] [Indexed: 12/21/2022] Open
Abstract
Mammalian myosin-5b (Myo5b) plays a critical role in the recycling of endosomes to the plasma membrane via the interactions with Rab11a and the Rab11 family interacting protein 2 (FIP2). However, it remains unclear on how Rab11a and FIP2 are coordinated in tethering Myo5b with the vesicles and activating the motor function of Myo5b. In the present study, we show that Rab11a binds to the globular tail domain (GTD) of Myo5b and this binding abolishes the head–GTD interaction of Myo5b, thus activating the motor function of Myo5b. On the other hand, FIP2 directly interacts with both Rab11a and the tail of Myo5b, and the binding of FIP2 to Myo5b does not affect Myo5b motor function. Moreover, Rab11a displays higher affinity to FIP2 than to Myo5b, suggesting that Rab11a binds preferentially to FIP2 than to Myo5b. Based on the current findings, we propose that the association of Myo5b with vesicles is mediated by FIP2, which bridges Myo5b and the membrane-bound Rab11a, whereas the motor function of Myo5b is regulated by Rab11a.
Collapse
|
29
|
Abstract
Myosin motors power movements on actin filaments, whereas dynein and kinesin motors power movements on microtubules. The mechanisms of these motor proteins differ, but, in all cases, ATP hydrolysis and subsequent release of the hydrolysis products drives a cycle of interactions with the track (either an actin filament or a microtubule), resulting in force generation and directed movement.
Collapse
Affiliation(s)
- H Lee Sweeney
- Department of Pharmacology and Therapeutics and the Myology Institute, University of Florida, College of Medicine, Gainesville, Florida 32610-0267
| | - Erika L F Holzbaur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104
| |
Collapse
|
30
|
Abstract
The delivery of intracellular material within cells is crucial for maintaining normal function. Myosins transport a wide variety of cargo, ranging from vesicles to ribonuclear protein particles (RNPs), in plants, fungi, and metazoa. The properties of a given myosin transporter are adapted to move on different actin filament tracks, either on the disordered actin networks at the cell cortex or along highly organized actin bundles to distribute their cargo in a localized manner or move it across long distances in the cell. Transport is controlled by selective recruitment of the myosin to its cargo that also plays a role in activation of the motor.
Collapse
Affiliation(s)
- Margaret A Titus
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota 55455
| |
Collapse
|
31
|
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.
Collapse
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.
| |
Collapse
|
32
|
Loss of Myosin Vb in colorectal cancer is a strong prognostic factor for disease recurrence. Br J Cancer 2017; 117:1689-1701. [PMID: 29024942 PMCID: PMC5729446 DOI: 10.1038/bjc.2017.352] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 07/24/2017] [Accepted: 09/08/2017] [Indexed: 02/06/2023] Open
Abstract
Background: Selecting the most beneficial treatment regimens for colorectal cancer (CRC) patients remains challenging due to a lack of prognostic markers. Members of the Myosin family, proteins recognised to have a major role in trafficking and polarisation of cells, have recently been reported to be closely associated with several types of cancer and might thus serve as potential prognostic markers in the context of CRC. Methods: We used a previously established meta-analysis of publicly available gene expression data to analyse the expression of different members of the Myosin V family, namely MYO5A, 5B, and 5C, in CRC. Using laser-microdissected material as well as tissue microarrays from paired human CRC samples, we validated both RNA and protein expression of Myosin Vb (MYO5B) and its known adapter proteins (RAB8A and RAB25) in an independent patient cohort. Finally, we assessed the prognostic value of both MYO5B and its adapter-coupled combinatorial gene expression signatures. Results: The meta-analysis as well as an independent patient cohort study revealed a methylation-independent loss of MYO5B expression in CRC that matched disease progression. Although MYO5B mutations were identified in a small number of patients, these cannot be solely responsible for the common downregulation observed in CRC patients. Significantly, CRC patients with low MYO5B expression displayed shorter overall, disease-, and metastasis-free survival, a trend that was further reinforced when RAB8A expression was also taken into account. Conclusions: Our data identify MYO5B as a powerful prognostic biomarker in CRC, especially in early stages (stages I and II), which might help stratifying patients with stage II for adjuvant chemotherapy.
Collapse
|
33
|
Myosin Va's adaptor protein melanophilin enforces track selection on the microtubule and actin networks in vitro. Proc Natl Acad Sci U S A 2017; 114:E4714-E4723. [PMID: 28559319 DOI: 10.1073/pnas.1619473114] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pigment organelles, or melanosomes, are transported by kinesin, dynein, and myosin motors. As such, melanosome transport is an excellent model system to study the functional relationship between the microtubule- and actin-based transport systems. In mammalian melanocytes, it is well known that the Rab27a/melanophilin/myosin Va complex mediates actin-based transport in vivo. However, pathways that regulate the overall directionality of melanosomes on the actin/microtubule networks have not yet been delineated. Here, we investigated the role of PKA-dependent phosphorylation on the activity of the actin-based Rab27a/melanophilin/myosin Va transport complex in vitro. We found that melanophilin, specifically its C-terminal actin-binding domain (ABD), is a target of PKA. Notably, in vitro phosphorylation of the ABD closely recapitulated the previously described in vivo phosphorylation pattern. Unexpectedly, we found that phosphorylation of the ABD affected neither the interaction of the complex with actin nor its movement along actin tracks. Surprisingly, the phosphorylation state of melanophilin was instead important for reversible association with microtubules in vitro. Dephosphorylated melanophilin preferred binding to microtubules even in the presence of actin, whereas phosphorylated melanophilin associated with actin. Indeed, when actin and microtubules were present simultaneously, melanophilin's phosphorylation state enforced track selection of the Rab27a/melanophilin/myosin Va transport complex. Collectively, our results unmasked the regulatory dominance of the melanophilin adaptor protein over its associated motor and offer an unexpected mechanism by which filaments of the cytoskeletal network compete for the moving organelles to accomplish directional transport on the cytoskeleton in vivo.
Collapse
|
34
|
Ben-Johny M, Yue DN, Yue DT. Detecting stoichiometry of macromolecular complexes in live cells using FRET. Nat Commun 2016; 7:13709. [PMID: 27922011 PMCID: PMC5150656 DOI: 10.1038/ncomms13709] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/25/2016] [Indexed: 11/10/2022] Open
Abstract
The stoichiometry of macromolecular interactions is fundamental to cellular signalling yet challenging to detect from living cells. Fluorescence resonance energy transfer (FRET) is a powerful phenomenon for characterizing close-range interactions whereby a donor fluorophore transfers energy to a closely juxtaposed acceptor. Recognizing that FRET measured from the acceptor's perspective reports a related but distinct quantity versus the donor, we utilize the ratiometric comparison of the two to obtain the stoichiometry of a complex. Applying this principle to the long-standing controversy of calmodulin binding to ion channels, we find a surprising Ca2+-induced switch in calmodulin stoichiometry with Ca2+ channels—one calmodulin binds at basal cytosolic Ca2+ levels while two calmodulins interact following Ca2+ elevation. This feature is curiously absent for the related Na channels, also potently regulated by calmodulin. Overall, our assay adds to a burgeoning toolkit to pursue quantitative biochemistry of dynamic signalling complexes in living cells. Measuring the in vivo stoichiometry of protein-protein interactions is challenging. Here the authors take a FRET-based approach, quantifying stoichiometry based on ratiometric comparison of donor and acceptor fluorescence, and apply their method to report on a Ca2+-induced switch in calmodulin binding to Ca2+ ion channels.
Collapse
Affiliation(s)
- Manu Ben-Johny
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
| | - Daniel N Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
| | - David T Yue
- Calcium Signals Laboratory, Department of Biomedical Engineering, The Johns Hopkins University School of Medicine, Ross Building, Room 713, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
| |
Collapse
|
35
|
Pylypenko O, Welz T, Tittel J, Kollmar M, Chardon F, Malherbe G, Weiss S, Michel CIL, Samol-Wolf A, Grasskamp AT, Hume A, Goud B, Baron B, England P, Titus MA, Schwille P, Weidemann T, Houdusse A, Kerkhoff E. Coordinated recruitment of Spir actin nucleators and myosin V motors to Rab11 vesicle membranes. eLife 2016; 5. [PMID: 27623148 PMCID: PMC5021521 DOI: 10.7554/elife.17523] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Accepted: 08/18/2016] [Indexed: 12/22/2022] Open
Abstract
There is growing evidence for a coupling of actin assembly and myosin motor activity in cells. However, mechanisms for recruitment of actin nucleators and motors on specific membrane compartments remain unclear. Here we report how Spir actin nucleators and myosin V motors coordinate their specific membrane recruitment. The myosin V globular tail domain (MyoV-GTD) interacts directly with an evolutionarily conserved Spir sequence motif. We determined crystal structures of MyoVa-GTD bound either to the Spir-2 motif or to Rab11 and show that a Spir-2:MyoVa:Rab11 complex can form. The ternary complex architecture explains how Rab11 vesicles support coordinated F-actin nucleation and myosin force generation for vesicle transport and tethering. New insights are also provided into how myosin activation can be coupled with the generation of actin tracks. Since MyoV binds several Rab GTPases, synchronized nucleator and motor targeting could provide a common mechanism to control force generation and motility in different cellular processes.
Collapse
Affiliation(s)
- Olena Pylypenko
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Tobias Welz
- University Hospital Regensburg, Regensburg, Germany
| | - Janine Tittel
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Martin Kollmar
- Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Florian Chardon
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Gilles Malherbe
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Sabine Weiss
- University Hospital Regensburg, Regensburg, Germany
| | | | | | | | - Alistair Hume
- University of Nottingham, Nottingham, United Kingdom
| | - Bruno Goud
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | - Bruno Baron
- Institut Pasteur, Biophysics of Macromolecules and their Interactions, Paris, France.,CNRS, UMR 3528, Paris, France
| | - Patrick England
- Institut Pasteur, Biophysics of Macromolecules and their Interactions, Paris, France.,CNRS, UMR 3528, Paris, France
| | - Margaret A Titus
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, United States
| | - Petra Schwille
- Max Planck Institute of Biochemistry, Martinsried, Germany
| | | | - Anne Houdusse
- Institut Curie, PSL Research University, CNRS, UMR 144, F-75005, Paris, France
| | | |
Collapse
|
36
|
Autoinhibition of a Neuronal Kinesin UNC-104/KIF1A Regulates the Size and Density of Synapses. Cell Rep 2016; 16:2129-2141. [PMID: 27524618 DOI: 10.1016/j.celrep.2016.07.043] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/20/2016] [Accepted: 07/16/2016] [Indexed: 11/22/2022] Open
Abstract
Kinesin motor proteins transport intracellular cargoes throughout cells by hydrolyzing ATP and moving along microtubule tracks. Intramolecular autoinhibitory interactions have been shown for several kinesins in vitro; however, the physiological significance of autoinhibition remains poorly understood. Here, we identified four mutations in the stalk region and motor domain of the synaptic vesicle (SV) kinesin UNC-104/KIF1A that specifically disrupt autoinhibition. These mutations augment both microtubule and cargo vesicle binding in vitro. In vivo, these mutations cause excessive activation of UNC-104, leading to decreased synaptic density, smaller synapses, and ectopic localization of SVs in the dendrite. We also show that the SV-bound small GTPase ARL-8 activates UNC-104 by unlocking the autoinhibition. These results demonstrate that the autoinhibitory mechanism is used to regulate the distribution of transport cargoes and is important for synaptogenesis in vivo.
Collapse
|
37
|
Jana B, Onuchic JN. Strain Mediated Adaptation Is Key for Myosin Mechanochemistry: Discovering General Rules for Motor Activity. PLoS Comput Biol 2016; 12:e1005035. [PMID: 27494025 PMCID: PMC4975490 DOI: 10.1371/journal.pcbi.1005035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 06/25/2016] [Indexed: 11/18/2022] Open
Abstract
A structure-based model of myosin motor is built in the same spirit of our early work for kinesin-1 and Ncd towards physical understanding of its mechanochemical cycle. We find a structural adaptation of the motor head domain in post-powerstroke state that signals faster ADP release from it compared to the same from the motor head in the pre-powerstroke state. For dimeric myosin, an additional forward strain on the trailing head, originating from the postponed powerstroke state of the leading head in the waiting state of myosin, further increases the rate of ADP release. This coordination between the two heads is the essence of the processivity of the cycle. Our model provides a structural description of the powerstroke step of the cycle as an allosteric transition of the converter domain in response to the Pi release. Additionally, the variation in structural elements peripheral to catalytic motor domain is the deciding factor behind diverse directionalities of myosin motors (myosin V & VI). Finally, we observe that there are general rules for functional molecular motors across the different families. Allosteric structural adaptation of the catalytic motor head in different nucleotide states is crucial for mechanochemistry. Strain-mediated coordination between motor heads is essential for processivity and the variation of peripheral structural elements is essential for their diverse functionalities. Molecular motors are perhaps the most important proteins present in the cell. The importance specifically lies with the fact that these proteins use the chemical energy source (such as ATP) of the cell to generate mechanical work and perform a wide range of functionalities. In this article, we generalize the idea of using structure-based models to explore the mechanochemistry of myosin molecular motors in structural terms. We find that a structural adaptation of the motor head domain in post-powerstroke state signals faster ADP release from the trailing head to maintain its processivity while directionality arises from a careful design of peripheral structural elements. These results along with our earlier results on other motors provide a general rule for motor activity.
Collapse
Affiliation(s)
- Biman Jana
- Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India
- * E-mail: (BJ); (JNO)
| | - José N. Onuchic
- Center for Theoretical Biological Physics, Rice University, Houston, Texas, United States of America
- * E-mail: (BJ); (JNO)
| |
Collapse
|
38
|
Loss of cargo binding in the human myosin VI deafness mutant (R1166X) leads to increased actin filament binding. Biochem J 2016; 473:3307-19. [PMID: 27474411 PMCID: PMC5074368 DOI: 10.1042/bcj20160571] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 07/28/2016] [Indexed: 12/31/2022]
Abstract
Mutations in myosin VI have been associated with autosomal-recessive (DFNB37) and autosomal-dominant (DFNA22) deafness in humans. Here, we characterise an myosin VI nonsense mutation (R1166X) that was identified in a family with hereditary hearing loss in Pakistan. This mutation leads to the deletion of the C-terminal 120 amino acids of the myosin VI cargo-binding domain, which includes the WWY-binding motif for the adaptor proteins LMTK2, Tom1 as well as Dab2. Interestingly, compromising myosin VI vesicle-binding ability by expressing myosin VI with the R1166X mutation or with single point mutations in the adaptor-binding sites leads to increased F-actin binding of this myosin in vitro and in vivo As our results highlight the importance of cargo attachment for regulating actin binding to the motor domain, we perform a detailed characterisation of adaptor protein binding and identify single amino acids within myosin VI required for binding to cargo adaptors. We not only show that the adaptor proteins can directly interact with the cargo-binding tail of myosin VI, but our in vitro studies also suggest that multiple adaptor proteins can bind simultaneously to non-overlapping sites in the myosin VI tail. In conclusion, our characterisation of the human myosin VI deafness mutant (R1166X) suggests that defects in cargo binding may leave myosin VI in a primed/activated state with an increased actin-binding ability.
Collapse
|
39
|
Abstract
The myosin holoenzyme is a multimeric protein complex consisting of heavy chains and light chains. Myosin light chains are calmodulin family members which are crucially involved in the mechanoenzymatic function of the myosin holoenzyme. This review examines the diversity of light chains within the myosin superfamily, discusses interactions between the light chain and the myosin heavy chain as well as regulatory and structural functions of the light chain as a subunit of the myosin holoenzyme. It covers aspects of the myosin light chain in the localization of the myosin holoenzyme, protein-protein interactions and light chain binding to non-myosin binding partners. Finally, this review challenges the dogma that myosin regulatory and essential light chain exclusively associate with conventional myosin heavy chains while unconventional myosin heavy chains usually associate with calmodulin.
Collapse
Affiliation(s)
- Sarah M Heissler
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
| | - James R Sellers
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
| |
Collapse
|
40
|
Batters C, Veigel C. Mechanics and Activation of Unconventional Myosins. Traffic 2016; 17:860-71. [PMID: 27061900 DOI: 10.1111/tra.12400] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Revised: 03/07/2016] [Accepted: 03/07/2016] [Indexed: 12/01/2022]
Abstract
Many types of cellular motility are based on the myosin family of motor proteins ranging from muscle contraction to exo- and endocytosis, cytokinesis, cell locomotion or signal transduction in hearing. At the center of this wide range of motile processes lies the adaptation of the myosins for each specific mechanical task and the ability to coordinate the timing of motor protein mobilization and targeting. In recent years, great progress has been made in developing single molecule technology to characterize the diverse mechanical properties of the unconventional myosins. Here, we discuss the basic mechanisms and mechanical adaptations of unconventional myosins, and emerging principles regulating motor mobilization and targeting.
Collapse
Affiliation(s)
- Christopher Batters
- Department of Cellular Physiology, Ludwig-Maximilians-Universität München, Schillerstrasse 44, 80336, Munich, Germany.,Center for Nanosciences (CeNS) München, 80799, Munich, Germany
| | - Claudia Veigel
- Department of Cellular Physiology, Ludwig-Maximilians-Universität München, Schillerstrasse 44, 80336, Munich, Germany.,Center for Nanosciences (CeNS) München, 80799, Munich, Germany
| |
Collapse
|
41
|
Zhang WB, Yao LL, Li XD. The Globular Tail Domain of Myosin-5a Functions as a Dimer in Regulating the Motor Activity. J Biol Chem 2016; 291:13571-9. [PMID: 27129208 DOI: 10.1074/jbc.m116.724328] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Indexed: 11/06/2022] Open
Abstract
Myosin-5a contains two heavy chains, which are dimerized via the coiled-coil regions. Thus, myosin-5a comprises two heads and two globular tail domains (GTDs). The GTD is the inhibitory domain that binds to the head and inhibits its motor function. Although the two-headed structure is essential for the processive movement of myosin-5a along actin filaments, little is known about the role of GTD dimerization. Here, we investigated the effect of GTD dimerization on its inhibitory activity. We found that the potent inhibitory activity of the GTD is dependent on its dimerization by the preceding coiled-coil regions, indicating synergistic interactions between the two GTDs and the two heads of myosin-5a. Moreover, we found that alanine mutations of the two conserved basic residues at N-terminal extension of the GTD not only weaken the inhibitory activity of the GTD but also enhance the activation of myosin-5a by its cargo-binding protein melanophilin (Mlph). These results are consistent with the GTD forming a head to head dimer, in which the N-terminal extension of the GTD interacts with the Mlph-binding site in the counterpart GTD. The Mlph-binding site at the GTD-GTD interface must be exposed prior to the binding of Mlph. We therefore propose that the inhibited Myo5a is equilibrated between the folded state, in which the Mlph-binding site is buried, and the preactivated state, in which the Mlph-binding site is exposed, and that Mlph is able to bind to the Myo5a in preactivated state and activates its motor function.
Collapse
Affiliation(s)
- Wen-Bo Zhang
- From the 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 and the University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lin-Lin Yao
- From the 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 and
| | - Xiang-Dong Li
- From the 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 and
| |
Collapse
|
42
|
Heissler SM, Sellers JR. Kinetic Adaptations of Myosins for Their Diverse Cellular Functions. Traffic 2016; 17:839-59. [PMID: 26929436 DOI: 10.1111/tra.12388] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 02/25/2016] [Accepted: 02/25/2016] [Indexed: 12/18/2022]
Abstract
Members of the myosin superfamily are involved in all aspects of eukaryotic life. Their function ranges from the transport of organelles and cargos to the generation of membrane tension, and the contraction of muscle. The diversity of physiological functions is remarkable, given that all enzymatically active myosins follow a conserved mechanoenzymatic cycle in which the hydrolysis of ATP to ADP and inorganic phosphate is coupled to either actin-based transport or tethering of actin to defined cellular compartments. Kinetic capacities and limitations of a myosin are determined by the extent to which actin can accelerate the hydrolysis of ATP and the release of the hydrolysis products and are indispensably linked to its physiological tasks. This review focuses on kinetic competencies that - together with structural adaptations - result in myosins with unique mechanoenzymatic properties targeted to their diverse cellular functions.
Collapse
Affiliation(s)
- Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, B50/3523, Bethesda, MD 20892-8015, USA
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, B50/3523, Bethesda, MD 20892-8015, USA
| |
Collapse
|
43
|
Li J, Lu Q, Zhang M. Structural Basis of Cargo Recognition by Unconventional Myosins in Cellular Trafficking. Traffic 2016; 17:822-38. [PMID: 26842936 DOI: 10.1111/tra.12383] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2015] [Revised: 01/29/2016] [Accepted: 01/29/2016] [Indexed: 01/17/2023]
Abstract
Unconventional myosins are a superfamily of actin-based molecular motors playing diverse roles including cellular trafficking, mechanical supports, force sensing and transmission, etc. The variable neck and tail domains of unconventional myosins function to bind to specific cargoes including proteins and lipid vesicles and thus are largely responsible for the diverse cellular functions of myosins in vivo. In addition, the tail regions, together with their cognate cargoes, can regulate activities of the motor heads. This review outlines the advances made in recent years on cargo recognition and cargo binding-induced regulation of the activity of several unconventional myosins including myosin-I, V, VI and X in cellular trafficking. We approach this topic by describing a series of high-resolution structures of the neck and tail domains of these unconventional myosins either alone or in complex with their specific cargoes, and by discussing potential implications of these structural studies on cellular trafficking of these myosin motors.
Collapse
Affiliation(s)
- Jianchao Li
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Qing Lu
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Division of Life Science, State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.,Center of Systems Biology and Human Health, School of Science and Institute for Advanced Study, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| |
Collapse
|
44
|
Abstract
Molecular motors produce force when they interact with their cellular tracks. For myosin motors, the primary force-generating state has MgADP tightly bound, whereas myosin is strongly bound to actin. We have generated an 8-Å cryoEM reconstruction of this state for myosin V and used molecular dynamics flexed fitting for model building. We compare this state to the subsequent state on actin (Rigor). The ADP-bound structure reveals that the actin-binding cleft is closed, even though MgADP is tightly bound. This state is accomplished by a previously unseen conformation of the β-sheet underlying the nucleotide pocket. The transition from the force-generating ADP state to Rigor requires a 9.5° rotation of the myosin lever arm, coupled to a β-sheet rearrangement. Thus, the structure reveals the detailed rearrangements underlying myosin force generation as well as the basis of strain-dependent ADP release that is essential for processive myosins, such as myosin V.
Collapse
|
45
|
Alamo L, Qi D, Wriggers W, Pinto A, Zhu J, Bilbao A, Gillilan RE, Hu S, Padrón R. Conserved Intramolecular Interactions Maintain Myosin Interacting-Heads Motifs Explaining Tarantula Muscle Super-Relaxed State Structural Basis. J Mol Biol 2016; 428:1142-1164. [PMID: 26851071 DOI: 10.1016/j.jmb.2016.01.027] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 01/15/2016] [Accepted: 01/25/2016] [Indexed: 01/08/2023]
Abstract
Tarantula striated muscle is an outstanding system for understanding the molecular organization of myosin filaments. Three-dimensional reconstruction based on cryo-electron microscopy images and single-particle image processing revealed that, in a relaxed state, myosin molecules undergo intramolecular head-head interactions, explaining why head activity switches off. The filament model obtained by rigidly docking a chicken smooth muscle myosin structure to the reconstruction was improved by flexibly fitting an atomic model built by mixing structures from different species to a tilt-corrected 2-nm three-dimensional map of frozen-hydrated tarantula thick filament. We used heavy and light chain sequences from tarantula myosin to build a single-species homology model of two heavy meromyosin interacting-heads motifs (IHMs). The flexibly fitted model includes previously missing loops and shows five intramolecular and five intermolecular interactions that keep the IHM in a compact off structure, forming four helical tracks of IHMs around the backbone. The residues involved in these interactions are oppositely charged, and their sequence conservation suggests that IHM is present across animal species. The new model, PDB 3JBH, explains the structural origin of the ATP turnover rates detected in relaxed tarantula muscle by ascribing the very slow rate to docked unphosphorylated heads, the slow rate to phosphorylated docked heads, and the fast rate to phosphorylated undocked heads. The conservation of intramolecular interactions across animal species and the presence of IHM in bilaterians suggest that a super-relaxed state should be maintained, as it plays a role in saving ATP in skeletal, cardiac, and smooth muscles.
Collapse
Affiliation(s)
- Lorenzo Alamo
- Centro de Biología Estructural, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020A, Venezuela.
| | - Dan Qi
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Willy Wriggers
- Department of Mechanical and Aerospace Engineering, Old Dominion University, 5115 Hampton Boulevard, Norfolk, VA 23529, USA.
| | - Antonio Pinto
- Centro de Biología Estructural, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020A, Venezuela.
| | - Jingui Zhu
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Aivett Bilbao
- Centro de Biología Estructural, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020A, Venezuela.
| | - Richard E Gillilan
- Macromolecular Diffraction Facility, Cornell High Energy Synchrotron Source, 161 Wilson Laboratory, Synchrotron Drive, Ithaca, NY 14853, USA.
| | - Songnian Hu
- Key Laboratory of Genome Sciences and Information, Beijing Institute of Genomics, 1 Beichen West Road, Chaoyang District, Beijing 100101, China.
| | - Raúl Padrón
- Centro de Biología Estructural, Instituto Venezolano de Investigaciones Científicas, Apartado 20632, Caracas 1020A, Venezuela.
| |
Collapse
|
46
|
Heissler SM, Sellers JR. Various Themes of Myosin Regulation. J Mol Biol 2016; 428:1927-46. [PMID: 26827725 DOI: 10.1016/j.jmb.2016.01.022] [Citation(s) in RCA: 84] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/12/2016] [Accepted: 01/19/2016] [Indexed: 10/24/2022]
Abstract
Members of the myosin superfamily are actin-based molecular motors that are indispensable for cellular homeostasis. The vast functional and structural diversity of myosins accounts for the variety and complexity of the underlying allosteric regulatory mechanisms that determine the activation or inhibition of myosin motor activity and enable precise timing and spatial aspects of myosin function at the cellular level. This review focuses on the molecular basis of posttranslational regulation of eukaryotic myosins from different classes across species by allosteric intrinsic and extrinsic effectors. First, we highlight the impact of heavy and light chain phosphorylation. Second, we outline intramolecular regulatory mechanisms such as autoinhibition and subsequent activation. Third, we discuss diverse extramolecular allosteric mechanisms ranging from actin-linked regulatory mechanisms to myosin:cargo interactions. At last, we briefly outline the allosteric regulation of myosins with synthetic compounds.
Collapse
Affiliation(s)
- Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, 50 South Drive, B50/3529, Bethesda, MD 20892-8015, USA.
| | - James R Sellers
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, 50 South Drive, B50/3529, Bethesda, MD 20892-8015, USA
| |
Collapse
|
47
|
Abstract
The ability to coordinate the timing of motor protein activation lies at the center of a wide range of cellular motile processes including endocytosis, cell division, and cancer cell migration. We show that calcium dramatically alters the conformation and activity of the myosin-VI motor implicated in pivotal steps of these processes. We resolved the change in motor conformation and in structural flexibility using single particle analysis of electron microscopic data and identified interacting domains using fluorescence spectroscopy. We discovered that calcium binding to calmodulin increases the binding affinity by a factor of 2,500 for a bipartite binding site on myosin-VI. The ability of calcium-calmodulin to seek out and bridge between binding site components directs a major rearrangement of the motor from a compact dormant state into a cargo binding primed state that is nonmotile. The lack of motility at high calcium is due to calmodulin switching to a higher affinity binding site, which leaves the original IQ-motif exposed, thereby destabilizing the lever arm. The return to low calcium can either restabilize the lever arm, required for translocating the cargo-bound motors toward the center of the cell, or refold the cargo-free motors into an inactive state ready for the next cellular calcium flux.
Collapse
|
48
|
Flexural Stiffness of Myosin Va Subdomains as Measured from Tethered Particle Motion. JOURNAL OF BIOPHYSICS 2015; 2015:465693. [PMID: 26770194 PMCID: PMC4685436 DOI: 10.1155/2015/465693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Revised: 10/29/2015] [Accepted: 11/08/2015] [Indexed: 11/18/2022]
Abstract
Myosin Va (MyoVa) is a processive molecular motor involved in intracellular cargo transport on the actin cytoskeleton. The motor's processivity and ability to navigate actin intersections are believed to be governed by the stiffness of various parts of the motor's structure. Specifically, changes in calcium may regulate motor processivity by altering the motor's lever arm stiffness and thus its interhead communication. In order to measure the flexural stiffness of MyoVa subdomains, we use tethered particle microscopy, which relates the Brownian motion of fluorescent quantum dots, which are attached to various single- and double-headed MyoVa constructs bound to actin in rigor, to the motor's flexural stiffness. Based on these measurements, the MyoVa lever arm and coiled-coil rod domain have comparable flexural stiffness (0.034 pN/nm). Upon addition of calcium, the lever arm stiffness is reduced 40% as a result of calmodulins potentially dissociating from the lever arm. In addition, the flexural stiffness of the full-length MyoVa construct is an order of magnitude less stiff than both a single lever arm and the coiled-coil rod. This suggests that the MyoVa lever arm-rod junction provides a flexible hinge that would allow the motor to maneuver cargo through the complex intracellular actin network.
Collapse
|
49
|
Knoblach B, Rachubinski RA. Motors, anchors, and connectors: orchestrators of organelle inheritance. Annu Rev Cell Dev Biol 2015; 31:55-81. [PMID: 26443192 DOI: 10.1146/annurev-cellbio-100814-125553] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Organelle inheritance is a process whereby organelles are actively distributed between dividing cells at cytokinesis. Much valuable insight into the molecular mechanisms of organelle inheritance has come from the analysis of asymmetrically dividing cells, which transport a portion of their organelles to the bud while retaining another portion in the mother cell. Common principles apply to the inheritance of all organelles, although individual organelles use specific factors for their partitioning. Inheritance factors can be classified as motors, which are required for organelle transport; anchors, which immobilize organelles at distinct cell structures; or connectors, which mediate the attachment of organelles to motors and anchors. Here, we provide an overview of recent advances in the field of organelle inheritance and highlight how motor, anchor, and connector molecules choreograph the segregation of a multicopy organelle, the peroxisome. We also discuss the role of organelle population control in the generation of cellular diversity.
Collapse
Affiliation(s)
- Barbara Knoblach
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada;
| | - Richard A Rachubinski
- Department of Cell Biology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada;
| |
Collapse
|
50
|
Sakai T, Jung HS, Sato O, Yamada MD, You DJ, Ikebe R, Ikebe M. Structure and Regulation of the Movement of Human Myosin VIIA. J Biol Chem 2015; 290:17587-98. [PMID: 26001786 DOI: 10.1074/jbc.m114.599365] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Indexed: 11/06/2022] Open
Abstract
Human myosin VIIA (HM7A) is responsible for human Usher syndrome type 1B, which causes hearing and visual loss in humans. Here we studied the regulation of HM7A. The actin-activated ATPase activity of full-length HM7A (HM7AFull) was lower than that of tail-truncated HM7A (HM7AΔTail). Deletion of the C-terminal 40 amino acids and mutation of the basic residues in this region (R2176A or K2179A) abolished the inhibition. Electron microscopy revealed that HM7AFull is a monomer in which the tail domain bends back toward the head-neck domain to form a compact structure. This compact structure is extended at high ionic strength or in the presence of Ca(2+). Although myosin VIIA has five isoleucine-glutamine (IQ) motifs, the neck length seems to be shorter than the expected length of five bound calmodulins. Supporting this observation, the IQ domain bound only three calmodulins in Ca(2+), and the first IQ motif failed to bind calmodulin in EGTA. These results suggest that the unique IQ domain of HM7A is important for the tail-neck interaction and, therefore, regulation. Cellular studies revealed that dimer formation of HM7A is critical for its translocation to filopodial tips and that the tail domain (HM7ATail) markedly reduced the filopodial tip localization of the HM7AΔTail dimer, suggesting that the tail-inhibition mechanism is operating in vivo. The translocation of the HM7AFull dimer was significantly less than that of the HM7AΔTail dimer, and R2176A/R2179A mutation rescued the filopodial tip translocation. These results suggest that HM7A can transport its cargo molecules, such as USH1 proteins, upon release of the tail-dependent inhibition.
Collapse
Affiliation(s)
- Tsuyoshi Sakai
- From the Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01605, the Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708
| | - Hyun Suk Jung
- the Division of Electron Microscopic Research, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon 305-333, Korea, and the Department of Biochemistry, College of Natural Sciences, Kangwon National University, 1, Kangwondaehak-gil, Chuncheon-si, Gangwon-do 200-701, Korea
| | - Osamu Sato
- From the Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01605, the Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708
| | - Masafumi D Yamada
- From the Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Dong-Ju You
- the Division of Electron Microscopic Research, Korea Basic Science Institute, 169-148 Gwahak-ro, Daejeon 305-333, Korea, and
| | - Reiko Ikebe
- From the Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01605, the Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708
| | - Mitsuo Ikebe
- From the Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01605, the Department of Cellular and Molecular Biology, University of Texas Health Science Center at Tyler, Tyler, Texas 75708,
| |
Collapse
|