1
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Dhakal U, Kim HS, Toomajian C. The landscape and predicted roles of structural variants in Fusarium graminearum genomes. G3 (BETHESDA, MD.) 2024; 14:jkae065. [PMID: 38546739 DOI: 10.1093/g3journal/jkae065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 02/22/2024] [Indexed: 06/06/2024]
Abstract
Structural rearrangements, such as inversions, translocations, duplications, and large insertions and deletions, are large-scale genomic variants that can play an important role in shaping phenotypic variation and in genome adaptation and evolution. We used chromosomal-level assemblies from eight Fusarium graminearum isolates to study structural variants and their role in fungal evolution. We generated the assemblies of four of these genomes after Oxford Nanopore sequencing. A total of 87 inversions, 159 translocations, 245 duplications, 58,489 insertions, and 34,102 deletions were detected. Regions of high recombination rate are associated with structural rearrangements, and a significant proportion of inversions, translocations, and duplications overlap with the repeat content of the genome, suggesting recombination and repeat elements are major factors in the origin of structural rearrangements in F. graminearum. Large insertions and deletions introduce presence-absence polymorphisms for many genes, including secondary metabolite biosynthesis cluster genes and predicted effectors genes. Translocation events were found to be shuffling predicted effector-rich regions of the genomes and are likely contributing to the gain and loss of effectors facilitated by recombination. Breakpoints of some structural rearrangements fall within coding sequences and are likely altering the protein products. Structural rearrangements in F. graminearum thus have an important role to play in shaping pathogen-host interactions and broader evolution through genome reorganization, the introduction of presence-absence polymorphisms, and changing protein products and gene regulation.
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Affiliation(s)
- Upasana Dhakal
- Department of Plant Pathology, Kansas State University, Manhattan, KS 66506, USA
| | - Hye-Seon Kim
- USDA, Agricultural Research Service, National Center for Agricultural Utilization Research, Mycotoxin Prevention and Applied Microbiology Research Unit, 1815 N University St., Peoria, IL 61604, USA
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2
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Chiba K, Niwa S. Autoinhibition and activation of kinesin-1 and their involvement in amyotrophic lateral sclerosis. Curr Opin Cell Biol 2024; 86:102301. [PMID: 38096601 DOI: 10.1016/j.ceb.2023.102301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 11/11/2023] [Accepted: 11/22/2023] [Indexed: 02/15/2024]
Abstract
Kinesin-1, composed of kinesin heavy chain and kinesin light chain, is a founding member of kinesin superfamily and transports various neuronal cargos. Kinesin-1 is one of the most abundant ATPases in the cell and thus need to be tightly regulated to avoid wastage of energy. It has been well established that kinesin-1 is regulated by the autoinhibition mechanism. This review focuses on the recent researches that have contributed to the understanding of mechanisms for the autoinhibition of kinesin-1 and its unlocking. Recent electron microscopic studies have shown an unanticipated structure of autoinhibited kinesin-1. Biochemical reconstitution have revealed detailed molecular mechanisms how the autoinhibition is unlocked. Importantly, misregulation of kinesin-1 is emerging as one of the major causes of amyotrophic lateral sclerosis.
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Affiliation(s)
- Kyoko Chiba
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan
| | - Shinsuke Niwa
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, 6-3 Aramaki-Aoba, Aoba-ku, Sendai, Miyagi 980-0845, Japan; Graduate School of Life Sciences, Tohoku University, 2-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8578, Japan.
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3
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Tan Z, Yue Y, Leprevost F, Haynes S, Basrur V, Nesvizhskii AI, Verhey KJ, Cianfrocco MA. Autoinhibited kinesin-1 adopts a hierarchical folding pattern. eLife 2023; 12:RP86776. [PMID: 37910016 PMCID: PMC10619981 DOI: 10.7554/elife.86776] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Abstract
Conventional kinesin-1 is the primary anterograde motor in cells for transporting cellular cargo. While there is a consensus that the C-terminal tail of kinesin-1 inhibits motility, the molecular architecture of a full-length autoinhibited kinesin-1 remains unknown. Here, we combine crosslinking mass spectrometry (XL-MS), electron microscopy (EM), and AlphaFold structure prediction to determine the architecture of the full-length autoinhibited kinesin-1 homodimer (kinesin-1 heavy chain [KHC]) and kinesin-1 heterotetramer (KHC bound to kinesin light chain 1 [KLC1]). Our integrative analysis shows that kinesin-1 forms a compact, bent conformation through a break in coiled-coil 3. Moreover, our XL-MS analysis demonstrates that kinesin light chains stabilize the folded inhibited state rather than inducing a new structural state. Using our structural model, we show that disruption of multiple interactions between the motor, stalk, and tail domains is required to activate the full-length kinesin-1. Our work offers a conceptual framework for understanding how cargo adaptors and microtubule-associated proteins relieve autoinhibition to promote activation.
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Affiliation(s)
- Zhenyu Tan
- Department of Biophysics, University of MichiganAnn ArborUnited States
- Life Sciences Institute, University of MichiganAnn ArborUnited States
| | - Yang Yue
- Department of Cell & Developmental Biology, University of MichiganAnn ArborUnited States
| | - Felipe Leprevost
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Sarah Haynes
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Venkatesha Basrur
- Department of Pathology, University of MichiganAnn ArborUnited States
| | - Alexey I Nesvizhskii
- Department of Pathology, University of MichiganAnn ArborUnited States
- Department of Computational Medicine and Bioinformatics, University of MichiganAnn ArborUnited States
| | - Kristen J Verhey
- Department of Cell & Developmental Biology, University of MichiganAnn ArborUnited States
| | - Michael A Cianfrocco
- Life Sciences Institute, University of MichiganAnn ArborUnited States
- Department of Biological Chemistry, University of MichiganAnn ArborUnited States
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4
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Tan Z, Yue Y, da Veiga Leprevost F, Haynes SE, Basrur V, Nesvizhskii AI, Verhey KJ, Cianfrocco MA. Autoinhibited kinesin-1 adopts a hierarchical folding pattern. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.26.525761. [PMID: 36747757 PMCID: PMC9901034 DOI: 10.1101/2023.01.26.525761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Conventional kinesin-1 is the primary anterograde motor in cells for transporting cellular cargo. While there is a consensus that the C-terminal tail of kinesin-1 inhibits motility, the molecular architecture of a full-length autoinhibited kinesin-1 remains unknown. Here, we combine cross-linking mass spectrometry (XL-MS), electron microscopy (EM), and AlphaFold structure prediction to determine the architecture of the full-length autoinhibited kinesin-1 homodimer [kinesin-1 heavy chain (KHC)] and kinesin-1 heterotetramer [KHC bound to kinesin light chain 1 (KLC1)]. Our integrative analysis shows that kinesin-1 forms a compact, bent conformation through a break in coiled coil 3. Moreover, our XL-MS analysis demonstrates that kinesin light chains stabilize the folded inhibited state rather than inducing a new structural state. Using our structural model, we show that disruption of multiple interactions between the motor, stalk, and tail domains is required to activate the full-length kinesin-1. Our work offers a conceptual framework for understanding how cargo adaptors and microtubule-associated proteins relieve autoinhibition to promote activation.
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Affiliation(s)
- Zhenyu Tan
- Department of Biophysics, University of Michigan
- Life Sciences Institute, University of Michigan
| | - Yang Yue
- Department of Cell & Developmental Biology, University of Michigan
| | | | | | | | - Alexey I. Nesvizhskii
- Department of Pathology, University of Michigan
- Department of Computational Medicine and Bioinformatics, University of Michigan
| | | | - Michael A. Cianfrocco
- Life Sciences Institute, University of Michigan
- Department of Biological Chemistry, University of Michigan
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5
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Qiu R, Zhang J, Xiang X. Kinesin-1 autoinhibition facilitates the initiation of dynein cargo transport. J Biophys Biochem Cytol 2022; 222:213766. [PMID: 36524956 PMCID: PMC9802684 DOI: 10.1083/jcb.202205136] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 11/04/2022] [Accepted: 12/05/2022] [Indexed: 12/23/2022] Open
Abstract
The functional significance of Kinesin-1 autoinhibition has been unclear. Kinesin-1 transports multiple cargoes including cytoplasmic dynein to microtubule plus ends. From a genetic screen for Aspergillus mutants defective in dynein-mediated early endosome transport, we identified a kinesin-1 mutation kinAK895* at the C-terminal IAK motif involved in autoinhibition. The kinA∆IAK and kinAK895E mutants exhibited a similar defect in dynein-mediated early endosome transport, verifying the importance of kinesin-1 autoinhibition in dynein-mediated transport. Kinesin-1 autoinhibition is not critical for dynein accumulation at microtubule plus ends or for the secretory vesicle cargoes of kinesin-1 to reach the hyphal tip. However, it facilitates dynein to initiate early endosome transport. This is unrelated to a direct competition between dynein and kinesin-1 on early endosomes because kinesin-3 rather than kinesin-1 drives the plus-end-directed early endosome movement. This effect of kinesin-1 autoinhibition on dynein-mediated early endosome transport is related to cargo adapter-mediated dynein activation but at a step beyond the switching of dynein from its autoinhibited conformation.
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Affiliation(s)
- Rongde Qiu
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MA, USA
| | - Jun Zhang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MA, USA
| | - Xin Xiang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences, F. Edward Hébert School of Medicine, Bethesda, MA, USA,Correspondence to Xin Xiang:
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6
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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.
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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
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7
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Pant DC, Parameswaran J, Rao L, Loss I, Chilukuri G, Parlato R, Shi L, Glass JD, Bassell GJ, Koch P, Yilmaz R, Weishaupt JH, Gennerich A, Jiang J. ALS-linked KIF5A ΔExon27 mutant causes neuronal toxicity through gain-of-function. EMBO Rep 2022; 23:e54234. [PMID: 35735139 DOI: 10.15252/embr.202154234] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 06/01/2022] [Accepted: 06/03/2022] [Indexed: 12/23/2022] Open
Abstract
Mutations in the human kinesin family member 5A (KIF5A) gene were recently identified as a genetic cause of amyotrophic lateral sclerosis (ALS). Several KIF5A ALS variants cause exon 27 skipping and are predicted to produce motor proteins with an altered C-terminal tail (referred to as ΔExon27). However, the underlying pathogenic mechanism is still unknown. Here, we confirm the expression of KIF5A mutant proteins in patient iPSC-derived motor neurons. We perform a comprehensive analysis of ΔExon27 at the single-molecule, cellular, and organism levels. Our results show that ΔExon27 is prone to form cytoplasmic aggregates and is neurotoxic. The mutation relieves motor autoinhibition and increases motor self-association, leading to drastically enhanced processivity on microtubules. Finally, ectopic expression of ΔExon27 in Drosophila melanogaster causes wing defects, motor impairment, paralysis, and premature death. Our results suggest gain-of-function as an underlying disease mechanism in KIF5A-associated ALS.
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Affiliation(s)
- Devesh C Pant
- Department of Cell Biology, Emory University, Atlanta, GA, USA
| | | | - Lu Rao
- Department of Biochemistry and Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Isabel Loss
- Division of Neurodegenerative Disorders, Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences, Heidelberg University, Mannheim, Germany
| | | | - Rosanna Parlato
- Division of Neurodegenerative Disorders, Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences, Heidelberg University, Mannheim, Germany
| | - Liang Shi
- Department of Cell Biology, Emory University, Atlanta, GA, USA
| | | | - Gary J Bassell
- Department of Cell Biology, Emory University, Atlanta, GA, USA
| | - Philipp Koch
- Hector Institute of Translational Brain Research, Central Institute of Mental Health, University of Heidelberg/Medical Faculty Mannheim, Mannheim, Germany
| | - Rüstem Yilmaz
- Division of Neurodegenerative Disorders, Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences, Heidelberg University, Mannheim, Germany
| | - Jochen H Weishaupt
- Division of Neurodegenerative Disorders, Department of Neurology, Medical Faculty Mannheim, Mannheim Center for Translational Neurosciences, Heidelberg University, Mannheim, Germany
| | - Arne Gennerich
- Department of Biochemistry and Gruss Lipper Biophotonics Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Jie Jiang
- Department of Cell Biology, Emory University, Atlanta, GA, USA
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8
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Baron DM, Fenton AR, Saez-Atienzar S, Giampetruzzi A, Sreeram A, Shankaracharya, Keagle PJ, Doocy VR, Smith NJ, Danielson EW, Andresano M, McCormack MC, Garcia J, Bercier V, Van Den Bosch L, Brent JR, Fallini C, Traynor BJ, Holzbaur ELF, Landers JE. ALS-associated KIF5A mutations abolish autoinhibition resulting in a toxic gain of function. Cell Rep 2022; 39:110598. [PMID: 35385738 PMCID: PMC9134378 DOI: 10.1016/j.celrep.2022.110598] [Citation(s) in RCA: 40] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/02/2022] [Accepted: 03/09/2022] [Indexed: 12/13/2022] Open
Abstract
Understanding the pathogenic mechanisms of disease mutations is critical to advancing treatments. ALS-associated mutations in the gene encoding the microtubule motor KIF5A result in skipping of exon 27 (KIF5AΔExon27) and the encoding of a protein with a novel 39 amino acid residue C-terminal sequence. Here, we report that expression of ALS-linked mutant KIF5A results in dysregulated motor activity, cellular mislocalization, altered axonal transport, and decreased neuronal survival. Single-molecule analysis revealed that the altered C terminus of mutant KIF5A results in a constitutively active state. Furthermore, mutant KIF5A possesses altered protein and RNA interactions and its expression results in altered gene expression/splicing. Taken together, our data support the hypothesis that causative ALS mutations result in a toxic gain of function in the intracellular motor KIF5A that disrupts intracellular trafficking and neuronal homeostasis.
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Affiliation(s)
- Desiree M Baron
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Adam R Fenton
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Sara Saez-Atienzar
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD 20892, USA
| | - Anthony Giampetruzzi
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Aparna Sreeram
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Shankaracharya
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Pamela J Keagle
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Victoria R Doocy
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Nathan J Smith
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA
| | - Eric W Danielson
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Megan Andresano
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Mary C McCormack
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Jaqueline Garcia
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Valérie Bercier
- KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Ludo Van Den Bosch
- KU Leuven-University of Leuven, Department of Neurosciences, Experimental Neurology and Leuven Brain Institute (LBI), Leuven, Belgium; VIB, Center for Brain & Disease Research, Laboratory of Neurobiology, Leuven, Belgium
| | - Jonathan R Brent
- Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Claudia Fallini
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA; George and Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI 02881, USA; Department of Cell and Molecular Biology, University of Rhode Island, Kingston, RI 02881, USA; Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Bryan J Traynor
- Neuromuscular Diseases Research Section, Laboratory of Neurogenetics, National Institute on Aging, NIH, Bethesda, MD 20892, USA; Department of Neurology, Johns Hopkins University, Baltimore, MD 21287, USA; Therapeutic Development Branch, National Center for Advancing Translational Sciences, NIH, Rockville, MD 20850, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Pennsylvania Muscle Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - John E Landers
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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9
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Raudaskoski M. Kinesin Motors in the Filamentous Basidiomycetes in Light of the Schizophyllum commune Genome. J Fungi (Basel) 2022; 8:jof8030294. [PMID: 35330296 PMCID: PMC8950801 DOI: 10.3390/jof8030294] [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: 02/12/2022] [Revised: 03/03/2022] [Accepted: 03/08/2022] [Indexed: 12/10/2022] Open
Abstract
Kinesins are essential motor molecules of the microtubule cytoskeleton. All eukaryotic organisms have several genes encoding kinesin proteins, which are necessary for various cell biological functions. During the vegetative growth of filamentous basidiomycetes, the apical cells of long leading hyphae have microtubules extending toward the tip. The reciprocal exchange and migration of nuclei between haploid hyphae at mating is also dependent on cytoskeletal structures, including the microtubules and their motor molecules. In dikaryotic hyphae, resulting from a compatible mating, the nuclear location, synchronous nuclear division, and extensive nuclear separation at telophase are microtubule-dependent processes that involve unidentified molecular motors. The genome of Schizophyllum commune is analyzed as an example of a species belonging to the Basidiomycota subclass, Agaricomycetes. In this subclass, the investigation of cell biology is restricted to a few species. Instead, the whole genome sequences of several species are now available. The analyses of the mating type genes and the genes necessary for fruiting body formation or wood degrading enzymes in several genomes of Agaricomycetes have shown that they are controlled by comparable systems. This supports the idea that the genes regulating the cell biological process in a model fungus, such as the genes encoding kinesin motor molecules, are also functional in other filamentous Agaricomycetes.
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Affiliation(s)
- Marjatta Raudaskoski
- Molecular Plant Biology, Department of Life Technologies, University of Turku, 20014 Turku, Finland
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10
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Impact of 719Trp>Arg Polymorphism of KIF 6 Gene on Contrast Induced Nephropathy in Patients Undergoing Coronary Angiography or Percutaneous Coronary Intervention. Glob Heart 2022; 17:16. [PMID: 35342690 PMCID: PMC8896252 DOI: 10.5334/gh.1105] [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: 02/04/2022] [Accepted: 02/04/2022] [Indexed: 11/20/2022] Open
Abstract
Background: The identification of preventive strategies, such as statin therapy, is crucial for the management of contrast-induced nephropathy (CIN). Several studies showed the association between KIF6 polymorphism (replacement of Trp719 with Arg) and an increased cardiovascular risk, while others showed a correlation between ‘pleiotropic’ effects of statins and a reduction in cardiovascular events in the population with the risk allele due to the documented modulation of response to statin by KIF6 polymorphism. Aim of this study is to assess the impact of KIF6 polymorphism on the development of CIN. Methods: We analysed 1253 consecutive patients undergoing coronary angiography/PCI. Serum creatinine was collected at baseline, 24 and 48 hours after contrast exposure. We identified the different allelic patterns and assessed the incidence of CIN (absolute increase of 0.5mg/dL or relative >25% in creatinine at 24 and 48h). Results: KIF6 Arg mutation was found in 669 patients (heterozygotes n = 525, homozygotes n = 144). The total prevalence of CIN was 12.5% and we did not find any association between KIF6 polymorphism and CIN development (11.3%, 13.7%, 13.2% p = 0.30). At subgroups analysis among statin ‘naïve’ patients we found a higher prevalence of CIN in homozygous patients as compared to wild-type (20.7% vs 11.3%, p = 0.05), while opposite results were observed among patients with statin therapy (8.6% vs 13.2%, p = 0.28). Conclusion: KIF6 homozygous Arg was associated with a significant increase in the risk of CIN only among statin naive patients. Future studies are needed to evaluate the beneficial effects of statin especially in this subset of patients.
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Shin EY, Lee CS, Kim HB, Park JH, Oh K, Lee GW, Cho EY, Kim HK, Kim EG. Kinesin-1-dependent transport of the βPIX/GIT complex in neuronal cells. BMB Rep 2021. [PMID: 34154701 PMCID: PMC8328822 DOI: 10.5483/bmbrep.2021.54.7.061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Eun-Young Shin
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | - Chan-Soo Lee
- Department of Food Standard Division Scientific Office, Ministry of Food and Drug Safety (KFDA), Cheongju 28159, Korea
| | - Han-Byeol Kim
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | - Jin-Hee Park
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | - Kwangseok Oh
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | - Gun-Wu Lee
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | - Eun-Yul Cho
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
| | | | - Eung-Gook Kim
- Department of Biochemistry and 3Microbiology, College of Medicine, and Medical Research Center, Chungbuk National University, Cheongju 28644, Korea
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12
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Antón Z, Weijman JF, Williams C, Moody ERR, Mantell J, Yip YY, Cross JA, Williams TA, Steiner RA, Crump MP, Woolfson DN, Dodding MP. Molecular mechanism for kinesin-1 direct membrane recognition. SCIENCE ADVANCES 2021; 7:7/31/eabg6636. [PMID: 34321209 PMCID: PMC8318374 DOI: 10.1126/sciadv.abg6636] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
The cargo-binding capabilities of cytoskeletal motor proteins have expanded during evolution through both gene duplication and alternative splicing. For the light chains of the kinesin-1 family of microtubule motors, this has resulted in an array of carboxyl-terminal domain sequences of unknown molecular function. Here, combining phylogenetic analyses with biophysical, biochemical, and cell biology approaches, we identify a highly conserved membrane-induced curvature-sensitive amphipathic helix within this region of a subset of long kinesin light-chain paralogs and splice isoforms. This helix mediates the direct binding of kinesin-1 to lipid membranes. Membrane binding requires specific anionic phospholipids, and it contributes to kinesin-1-dependent lysosome positioning, a canonical activity that, until now, has been attributed exclusively the recognition of organelle-associated cargo adaptor proteins. This leads us to propose a protein-lipid coincidence detection framework for kinesin-1-mediated organelle transport.
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Affiliation(s)
- Zuriñe Antón
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Johannes F Weijman
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Christopher Williams
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Edmund R R Moody
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Judith Mantell
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Yan Y Yip
- Randall Centre of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jessica A Cross
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
| | - Tom A Williams
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Roberto A Steiner
- Randall Centre of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Matthew P Crump
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Derek N Woolfson
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Mark P Dodding
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK.
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13
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Dimitrova-Paternoga L, Jagtap PKA, Cyrklaff A, Vaishali, Lapouge K, Sehr P, Perez K, Heber S, Löw C, Hennig J, Ephrussi A. Molecular basis of mRNA transport by a kinesin-1-atypical tropomyosin complex. Genes Dev 2021; 35:976-991. [PMID: 34140355 PMCID: PMC8247599 DOI: 10.1101/gad.348443.121] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 05/14/2021] [Indexed: 11/24/2022]
Abstract
Here, Dimitrova-Paternoga et al. present the high-resolution crystal structure of Khc–aTm1 (Drosophila kinesin-1, also called kinesin heavy chain [Khc], in complex with a putative cargo adaptor, the atypical tropomyosin [aTm1]), which mediates transport of oskar mRNA to the posterior pole of the Drosophila oocyte. They show that aTm1 binds to an evolutionarily conserved cargo binding site on Khc, demonstrate that Khc binds RNA directly, and show that aTm1 plays a stabilizing role in the interaction of Khc with RNA, which distinguishes aTm1 from classical motor adaptors. Kinesin-1 carries cargos including proteins, RNAs, vesicles, and pathogens over long distances within cells. The mechanochemical cycle of kinesins is well described, but how they establish cargo specificity is not fully understood. Transport of oskar mRNA to the posterior pole of the Drosophila oocyte is mediated by Drosophila kinesin-1, also called kinesin heavy chain (Khc), and a putative cargo adaptor, the atypical tropomyosin, aTm1. How the proteins cooperate in mRNA transport is unknown. Here, we present the high-resolution crystal structure of a Khc–aTm1 complex. The proteins form a tripartite coiled coil comprising two in-register Khc chains and one aTm1 chain, in antiparallel orientation. We show that aTm1 binds to an evolutionarily conserved cargo binding site on Khc, and mutational analysis confirms the importance of this interaction for mRNA transport in vivo. Furthermore, we demonstrate that Khc binds RNA directly and that it does so via its alternative cargo binding domain, which forms a positively charged joint surface with aTm1, as well as through its adjacent auxiliary microtubule binding domain. Finally, we show that aTm1 plays a stabilizing role in the interaction of Khc with RNA, which distinguishes aTm1 from classical motor adaptors.
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Affiliation(s)
- Lyudmila Dimitrova-Paternoga
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany.,Structural and Computational Biology Unit, EMBL Heidelberg, 69117 Heidelberg, Germany.,Centre for Structural Systems Biology (CSSB), Deutsches Elektronen-Synchrotron (DESY), EMBL Hamburg, 22607 Hamburg, Germany
| | | | - Anna Cyrklaff
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Vaishali
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany.,Faculty of Biosciences, Heidelberg University, 69120 Heidelberg, Germany
| | - Karine Lapouge
- Protein Expression and Purification Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Peter Sehr
- Chemical Biology Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Kathryn Perez
- Protein Expression and Purification Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Simone Heber
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
| | - Christian Löw
- Centre for Structural Systems Biology (CSSB), Deutsches Elektronen-Synchrotron (DESY), EMBL Hamburg, 22607 Hamburg, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Anne Ephrussi
- Developmental Biology Unit, European Molecular Biology Laboratory (EMBL) Heidelberg, 69117 Heidelberg, Germany
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14
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Yoo KS, Lee K, Oh JY, Lee H, Park H, Park YS, Kim HK. Postsynaptic density protein 95 (PSD-95) is transported by KIF5 to dendritic regions. Mol Brain 2019; 12:97. [PMID: 31753031 PMCID: PMC6873588 DOI: 10.1186/s13041-019-0520-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 11/04/2019] [Indexed: 11/18/2022] Open
Abstract
Postsynaptic density protein 95 (PSD-95) is a pivotal postsynaptic scaffolding protein in excitatory neurons. Although the transport and regulation of PSD-95 in synaptic regions is well understood, dendritic transport of PSD-95 before synaptic localization still remains to be clarified. To evaluate the role of KIF5, conventional kinesin, in the dendritic transport of PSD-95 protein, we expressed a transport defective form of KIF5A (ΔMD) that does not contain the N-terminal motor domain. Expression of ΔMD significantly decreased PSD-95 level in the dendrites. Consistently, KIF5 was associated with PSD-95 in in vitro and in vivo assays. This interaction was mediated by the C-terminal tail regions of KIF5A and the third PDZ domain of PSD-95. Additionally, the ADPDZ3 (the association domain of NMDA receptor and PDZ3 domain) expression significantly reduced the levels of PSD-95, glutamate receptor 1 (GluA1) in dendrites. The association between PSD-95 and KIF5A was dose-dependent on Staufen protein, suggesting that the Staufen plays a role as a regulatory role in the association. Taken together, our data suggest a new mechanism for dendritic transport of the AMPA receptor-PSD-95.
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Affiliation(s)
- Ki-Seo Yoo
- Department of Medicine and Microbiology, Graduate Program in Neuroscience, College of Medicine, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, 28644, South Korea
| | - Kina Lee
- Department of Medicine and Microbiology, Graduate Program in Neuroscience, College of Medicine, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, 28644, South Korea
| | - Jun-Young Oh
- Department of Medicine and Microbiology, Graduate Program in Neuroscience, College of Medicine, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, 28644, South Korea.,Department of Structure and Function of Neural Network, Korea Brain Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, 41068, South Korea
| | - Hyoeun Lee
- Department of Structure and Function of Neural Network, Korea Brain Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, 41068, South Korea
| | - Hyungju Park
- Department of Structure and Function of Neural Network, Korea Brain Research Institute, 61 Cheomdan-ro, Dong-gu, Daegu, 41068, South Korea
| | - Young Seok Park
- Department of Neurosurgery, Graduate Program in Neuroscience, College of Medicine, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, 28644, South Korea
| | - Hyong Kyu Kim
- Department of Medicine and Microbiology, Graduate Program in Neuroscience, College of Medicine, Chungbuk National University, 1 Chungdae-ro, Seowon-gu, Cheongju, 28644, South Korea.
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15
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Cockburn JJB, Hesketh SJ, Mulhair P, Thomsen M, O'Connell MJ, Way M. Insights into Kinesin-1 Activation from the Crystal Structure of KLC2 Bound to JIP3. Structure 2018; 26:1486-1498.e6. [PMID: 30197037 PMCID: PMC6224480 DOI: 10.1016/j.str.2018.07.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 06/03/2018] [Accepted: 07/25/2018] [Indexed: 12/11/2022]
Abstract
Kinesin-1 transports numerous cellular cargoes along microtubules. The kinesin-1 light chain (KLC) mediates cargo binding and regulates kinesin-1 motility. To investigate the molecular basis for kinesin-1 recruitment and activation by cargoes, we solved the crystal structure of the KLC2 tetratricopeptide repeat (TPR) domain bound to the cargo JIP3. This, combined with biophysical and molecular evolutionary analyses, reveals a kinesin-1 cargo binding site, located on KLC TPR1, which is conserved in homologs from sponges to humans. In the complex, JIP3 crosslinks two KLC2 TPR domains via their TPR1s. We show that TPR1 forms a dimer interface that mimics JIP3 binding in all crystal structures of the unbound KLC TPR domain. We propose that cargo-induced dimerization of the KLC TPR domains via TPR1 is a general mechanism for activating kinesin-1. We relate this to activation by tryptophan-acidic cargoes, explaining how different cargoes activate kinesin-1 through related molecular mechanisms.
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Affiliation(s)
- Joseph J B Cockburn
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK.
| | - Sophie J Hesketh
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Peter Mulhair
- Computational and Molecular Evolutionary Biology Research Group, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Maren Thomsen
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, UK
| | - Mary J O'Connell
- Computational and Molecular Evolutionary Biology Research Group, Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
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16
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Robert A, Tian P, Adam SA, Kittisopikul M, Jaqaman K, Goldman RD, Gelfand VI. Kinesin-dependent transport of keratin filaments: a unified mechanism for intermediate filament transport. FASEB J 2018; 33:388-399. [PMID: 29944446 PMCID: PMC6355078 DOI: 10.1096/fj.201800604r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Keratin intermediate filaments (IFs) are the major cytoskeletal component in epithelial cells. The dynamics of keratin IFs have been described to depend mostly on the actin cytoskeleton, but the rapid transport of fully polymerized keratin filaments has not been reported. In this work, we used a combination of photoconversion experiments and clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeats-associated protein 9 genome editing to study the role of microtubules and microtubule motors in keratin filament transport. We found that long keratin filaments, like other types of IFs, are transported along microtubules by kinesin-1. Our data revealed that keratin and vimentin are nonconventional kinesin-1 cargoes because their transport did not require kinesin light chains, which are a typical adapter for kinesin-dependent cargo transport. Furthermore, we found that the same domain of the kinesin heavy chain tail is involved in keratin and vimentin IF transport, strongly suggesting that multiple types of IFs move along microtubules using an identical mechanism.-Robert, A., Tian, P., Adam, S. A., Kittisopikul, M., Jaqaman, K., Goldman, R. D., Gelfand, V. I. Kinesin-dependent transport of keratin filaments: a unified mechanism for intermediate filament transport.
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Affiliation(s)
- Amélie Robert
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Peirun Tian
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Stephen A Adam
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Mark Kittisopikul
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA.,Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA; and
| | - Khuloud Jaqaman
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA; and.,Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Vladimir I Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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17
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Misiura M, Wang Q, Cheung MS, Kolomeisky AB. Theoretical Investigations of the Role of Mutations in Dynamics of Kinesin Motor Proteins. J Phys Chem B 2018; 122:4653-4661. [PMID: 29630822 DOI: 10.1021/acs.jpcb.8b00830] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Motor proteins are active enzymatic molecules that are critically important for a variety of biological phenomena. It is known that some neurodegenerative diseases are caused by specific mutations in motor proteins that lead to their malfunctioning. Hereditary spastic paraplegia is one of such diseases, and it is associated with the mutations in the neuronal conventional kinesin gene, producing the decreased speed and processivity of this motor protein. Despite the importance of this problem, there is no clear understanding on the role of mutations in modifying dynamic properties of motor proteins. In this work, we investigate theoretically the molecular basis for negative effects of two specific mutations, N256S and R280S, on the dynamics of kinesin motor proteins. We hypothesize that these mutations might accelerate the adenosine triphosphate (ATP) release by increasing the probability of open conformations for the ATP-binding pocket. Our approach is based on the use of coarse-grained structure-based molecular dynamics simulations to analyze the conformational changes and chemical transitions in the kinesin molecule, which is also supplemented by investigation of a mesoscopic discrete-state stochastic model. Computer simulations suggest that mutations N256S and R280S can decrease the free energy difference between open and closed biochemical states, making the open conformation more stable and the ATP release faster, which is in agreement with our hypothesis. Furthermore, we show that in the case of N256S mutation, this effect is caused by disruption of interactions between α helix and switch I and loop L11 structural elements. Our computational results are qualitatively supported by the explicit analysis of the discrete-state stochastic model.
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Affiliation(s)
| | | | - Margaret S Cheung
- Department of Physics , University of Houston , Houston , Texas 77204 , United States
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18
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Tian S, Wu J, Li F, Zou J, Liu Y, Zhou B, Bai Y, Sun MX. NtKRP, a kinesin-12 protein, regulates embryo/seed size and seed germination via involving in cell cycle progression at the G2/M transition. Sci Rep 2016; 6:35641. [PMID: 27779252 PMCID: PMC5078848 DOI: 10.1038/srep35641] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 10/03/2016] [Indexed: 01/01/2023] Open
Abstract
Kinesins comprise a superfamily of microtubule-based motor proteins involved in essential processes in plant development, but few kinesins have been functionally identified during seed development. Especially, few kinesins that regulate cell division during embryogenesis have been identified. Here we report the functional characterization of NtKRP, a motor protein of the kinesin-12 family. NtKRP is predominantly expressed in embryos and embryonic roots. NtKRP RNAi lines displayed reductions in cell numbers in the meristematic zone, in embryonic root length, and in mature embryo and seed sizes. Furthermore, we also show that CDKA;1 binds to NtKRP at the consensus phosphorylation sites and that the decreased cell numbers in NtKRP-silenced embryos are due to a delay in cell division cycle at the G2/M transition. In addition, binding between the cargo-binding tail domain of NtKRP and CDKA; 1 was also determined. Our results reveal a novel molecular pathway that regulates embryo/seed development and critical role of kinesin in temporal and spatial regulation of a specific issue of embryo developmental.
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Affiliation(s)
- Shujuan Tian
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Jingjing Wu
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Fen Li
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
- College of Life Science, Henan Normal University, Xinxiang 453007, China
| | - Jianwei Zou
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Yuwen Liu
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Bing Zhou
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Yang Bai
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
| | - Meng-Xiang Sun
- College of Life Sciences, State Key Laboratory of Hybrid Rice, Wuhan University, Wuhan, 430072, China
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19
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Veeranan-Karmegam R, Boggupalli DP, Liu G, Gonsalvez GB. A new isoform of Drosophila non-muscle Tropomyosin 1 interacts with Kinesin-1 and functions in oskar mRNA localization. J Cell Sci 2016; 129:4252-4264. [PMID: 27802167 DOI: 10.1242/jcs.194332] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/05/2016] [Indexed: 12/16/2022] Open
Abstract
Recent studies have revealed that diverse cell types use mRNA localization as a means to establish polarity. Despite the prevalence of this phenomenon, much less is known regarding the mechanism by which mRNAs are localized. The Drosophila melanogaster oocyte provides a useful model for examining the process of mRNA localization. oskar (osk) mRNA is localized at the posterior of the oocyte, thus restricting the expression of Oskar protein to this site. The localization of osk mRNA is microtubule dependent and requires the plus-end-directed motor Kinesin-1. Unlike most Kinesin-1 cargoes, localization of osk mRNA requires the Kinesin heavy chain (Khc) motor subunit, but not the Kinesin light chain (Klc) adaptor. In this report, we demonstrate that a newly discovered isoform of Tropomyosin 1, referred to as Tm1C, directly interacts with Khc and functions in concert with this microtubule motor to localize osk mRNA. Apart from osk mRNA localization, several additional Khc-dependent processes in the oocyte are unaffected upon loss of Tm1C. Our results therefore suggest that the Tm1C-Khc interaction is specific for the osk localization pathway.
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Affiliation(s)
- Rajalakshmi Veeranan-Karmegam
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1459 Laney Walker Blvd, Augusta, GA 30912, USA
| | - Devi Prasad Boggupalli
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1459 Laney Walker Blvd, Augusta, GA 30912, USA
| | - Guojun Liu
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1459 Laney Walker Blvd, Augusta, GA 30912, USA
| | - Graydon B Gonsalvez
- Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, 1459 Laney Walker Blvd, Augusta, GA 30912, USA
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20
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Vatte C, Cyrus C, Al Shehri AM, Chathoth S, Almansori M, Al-Nafaie A, Al-Ali R, Al-Muhanna F, Asselbergs FW, Al-Ali A. Investigation of KIF6 Trp719Arg gene polymorphism in a case-control study of coronary artery disease and non-fatal myocardial infarction in the Eastern Province of Saudi Arabia. Ann Saudi Med 2016; 36:105-11. [PMID: 26997531 PMCID: PMC6074390 DOI: 10.5144/0256-4947.2016.21.3.1140] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
BACKGROUND Kinesin-like protein 6 (KIF6), a member of the kinesin superfamily, is involved in intracellular transport. A few prospective studies have shown the KIF6 variant Trp719Arg (rs20455) to be associated with coronary artery disease (CAD) in Caucasian populations. However, recent genome-wide association studies on CAD have not proven these associations. OBJECTIVES Since the role of KIF6 719Arg allele in other ethnic populations is largely unknown, we sought to determine whether the KIF6 719Arg allele is associated with CAD in an ethnic Middle Eastern population. DESIGN Case-control study. SETTING CAD patients and control subjects from King Fahd Hospital of the University, Al-Khobar, Saudi Arabia. PATIENTS AND METHODS The study population included angiographically defined CAD patients (n=1002) and controls (n=984) with a normal electrocardiogram. MAIN OUTCOME MEASURE(S) Association of KIF6 Trp719Arg mutation with CAD. RESULTS The KIF6 Trp719Arg polymorphism was not associated with CAD (OR 0.976, 95% CI 0.861-1.105; P=.704). In addition, KIF6 Trp719Arg polymorphism showed a lack of association even in stratified myocardial infarction patients (n=802) (OR 1.006, 95% CI 0.881-1.148; P=.929) in comparison to controls. CONCLUSIONS The absence of Trp719Arg polymorphism association with CAD and CAD in stratified myocardial infarction cases indicates that the polymorphism is not associated with an increased risk among CAD patients from the Eastern Province of Saudi Arabia. LIMITATIONS Unavailability of data on statin usage among the patient population.
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Affiliation(s)
| | - Cyril Cyrus
- Dr. Cyril Cyrus, University of Dammam, 31441 Saudi Arabia, T: +96613330866,
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21
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Thiede C, Fridman V, Gerson-Gurwitz A, Gheber L, Schmidt CF. Regulation of bi-directional movement of single kinesin-5 Cin8 molecules. BIOARCHITECTURE 2014; 2:70-74. [PMID: 22754632 PMCID: PMC3383724 DOI: 10.4161/bioa.20395] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Kinesin-5 mechanoenzymes drive mitotic spindle dynamics as slow, processive microtubule (MT)-plus-end directed motors. Surprisingly, the Saccharomyces cerevisiae kinesin-5 Cin8 was recently found to be bi-directional: it can move processively in both directions on MTs. Two hypotheses have been suggested for the mechanism of the directionality switch: (1) single molecules of Cin8 are intrinsically minus-end directed, but mechanical coupling between two or more motors triggers the switch; (2) a single motor can switch direction, and "cargo binding" i.e., binding between two MTs triggers the switch to plus-end motility. Single-molecule fluorescence data we published recently, and augment here, favor hypothesis (2). In low-ionic-strength conditions, single molecules of Cin8 move in both minus- and plus-end directions. Fluorescence photo bleaching data rule out aggregation of Cin8 while they move in the plus and in the minus direction. The evidence thus points toward cargo regulation of directionality, which is likely to be related to cargo regulation in other kinesins. The molecular mechanisms of this regulation, however, remain to be elucidated.
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22
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Fu C, Ao J, Dettmann A, Seiler S, Free SJ. Characterization of the Neurospora crassa cell fusion proteins, HAM-6, HAM-7, HAM-8, HAM-9, HAM-10, AMPH-1 and WHI-2. PLoS One 2014; 9:e107773. [PMID: 25279949 PMCID: PMC4184795 DOI: 10.1371/journal.pone.0107773] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/14/2014] [Indexed: 11/19/2022] Open
Abstract
Intercellular communication of vegetative cells and their subsequent cell fusion is vital for different aspects of growth, fitness, and differentiation of filamentous fungi. Cell fusion between germinating spores is important for early colony establishment, while hyphal fusion in the mature colony facilitates the movement of resources and organelles throughout an established colony. Approximately 50 proteins have been shown to be important for somatic cell-cell communication and fusion in the model filamentous fungus Neurospora crassa. Genetic, biochemical, and microscopic techniques were used to characterize the functions of seven previously poorly characterized cell fusion proteins. HAM-6, HAM-7 and HAM-8 share functional characteristics and are proposed to function in the same signaling network. Our data suggest that these proteins may form a sensor complex at the cell wall/plasma membrane for the MAK-1 cell wall integrity mitogen-activated protein kinase (MAPK) pathway. We also demonstrate that HAM-9, HAM-10, AMPH-1 and WHI-2 have more general functions and are required for normal growth and development. The activation status of the MAK-1 and MAK-2 MAPK pathways are altered in mutants lacking these proteins. We propose that these proteins may function to coordinate the activities of the two MAPK modules with other signaling pathways during cell fusion.
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Affiliation(s)
- Ci Fu
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Jie Ao
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
| | - Anne Dettmann
- Institute for Biology II, Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Stephan Seiler
- Institute for Biology II, Albert-Ludwigs University Freiburg, Freiburg, Germany
- Freiburg Institute for Advanced Studies (FRIAS), Albert-Ludwigs University Freiburg, Freiburg, Germany
| | - Stephen J. Free
- Department of Biological Sciences, SUNY University at Buffalo, Buffalo, New York, United States of America
- * E-mail:
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Kumar KRS, Kamei T, Fukaminato T, Tamaoki N. Complete ON/OFF photoswitching of the motility of a nanobiomolecular machine. ACS NANO 2014; 8:4157-65. [PMID: 24680285 DOI: 10.1021/nn5010342] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
To apply motor proteins as natural nanomolecular machines to transporting systems in nanotechnology, complete temporal control over ON/OFF switching of the motility is necessary. We have studied the photoresponsive inhibition properties of azobenzene-tethered peptides for regulation of kinesin-microtubule motility. Although a compound containing a peptide having an amino acid sequence derived from the kinesin's C-terminus (a known inhibitor of kinesin's motor domain) and also featuring a terminal azobenzene unit exhibited an inhibition effect, the phototunability of this behavior upon irradiation with UV or visible light was only moderate. Unexpectedly, newly synthesized peptides featuring the reverse sequence of amino acids of the C-terminus of kinesin exhibited excellent photoresponsive inhibition. In particular, azobenzene-CONH-IPKAIQASHGR completely stopped and started the motility of kinesin-microtubules in its trans- and cis-rich states, respectively, obtained after irradiation with visible and UV light, respectively. A gliding motility system containing this photoresponsive inhibitor allowed in situ control of the motion of microtubules on a kinesin-coated glass substrate. It is expected that the present results on the photoresponsive nanomotor system open up new opportunities to design nanotransportation systems.
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Affiliation(s)
- K R Sunil Kumar
- Research Institute for Electronic Science, Hokkaido University , N20, W10, Kita-Ku, Sapporo, Hokkaido 001-0020, Japan
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24
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Human CFEOM1 mutations attenuate KIF21A autoinhibition and cause oculomotor axon stalling. Neuron 2014; 82:334-49. [PMID: 24656932 DOI: 10.1016/j.neuron.2014.02.038] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/10/2014] [Indexed: 12/16/2022]
Abstract
The ocular motility disorder "Congenital fibrosis of the extraocular muscles type 1" (CFEOM1) results from heterozygous mutations altering the motor and third coiled-coil stalk of the anterograde kinesin, KIF21A. We demonstrate that Kif21a knockin mice harboring the most common human mutation develop CFEOM. The developing axons of the oculomotor nerve's superior division stall in the proximal nerve; the growth cones enlarge, extend excessive filopodia, and assume random trajectories. Inferior division axons reach the orbit but branch ectopically. We establish a gain-of-function mechanism and find that human motor or stalk mutations attenuate Kif21a autoinhibition, providing in vivo evidence for mammalian kinesin autoregulation. We identify Map1b as a Kif21a-interacting protein and report that Map1b⁻/⁻ mice develop CFEOM. The interaction between Kif21a and Map1b is likely to play a critical role in the pathogenesis of CFEOM1 and highlights a selective vulnerability of the developing oculomotor nerve to perturbations of the axon cytoskeleton.
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25
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The Association between KIF6 Single Nucleotide Polymorphism rs20455 and Serum Lipids in Filipino-American Women. Nurs Res Pract 2014; 2014:328954. [PMID: 24587901 PMCID: PMC3920675 DOI: 10.1155/2014/328954] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2013] [Revised: 09/21/2013] [Accepted: 10/21/2013] [Indexed: 11/25/2022] Open
Abstract
The Trp719Arg allele of KIF6 rs20455, a putative risk factor for CHD especially in those with elevated low-density lipoprotein cholesterol (LDL-C), was investigated in Filipino-American women (FAW, n = 235) participating in health screenings in four cities. The rs20455 genotype of each subject was determined by a multiplex assay using a Luminex-OLA procedure. The risk allele Trp719Arg was present in 77% of the subjects. The genotype distribution was 23% Trp/Trp, 51% Arg/Trp, and 26% Arg/Arg. Genotype did not predict the presence of CHD risk factors. Moreover, LDL-C, HDL-C, and triglycerides mean values did not vary as a function of genotype. However, those with the Arg/Arg genotype on statin medication exhibited a significantly higher mean triglycerides level (P < 0.01). Approximately 60% of participants regardless of genotype exhibited LDL-C levels ≥100 mg/dL but were not taking medication. Approximately 43% of those with the Trp719Arg risk allele on statins exhibited elevated LDL-C levels. Our study suggests that the Trp719Arg allele of KIF 6 rs20455 is common among Filipino-American women; thus, even with borderline LDL-C levels would benefit from statin treatment. Secondly, many participants did not exhibit guideline recommended LDL-C levels including many who were on statin drugs.
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26
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Ganguly A, Dixit R. Mechanisms for regulation of plant kinesins. CURRENT OPINION IN PLANT BIOLOGY 2013; 16:704-9. [PMID: 24120300 DOI: 10.1016/j.pbi.2013.09.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 09/13/2013] [Accepted: 09/19/2013] [Indexed: 05/05/2023]
Abstract
Throughout the eukaryotic world, kinesins serve as molecular motors for the directional transport of cellular cargo along microtubule tracks. Plants contain a large number of kinesins that have conserved as well as specialized functions. These functions depend on mechanisms that regulate when, where and what kinesins transport. In this review, we highlight recent studies that have revealed conserved modes of regulation between plant kinesins and their non-photosynthetic counterparts. These findings lay the groundwork for understanding how plant kinesins are differentially engaged in various cellular processes that underlie plant growth and development.
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Affiliation(s)
- Anindya Ganguly
- Biology Department, Washington University, St. Louis, MO 63130, United States
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27
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Williams LS, Ganguly S, Loiseau P, Ng BF, Palacios IM. The auto-inhibitory domain and ATP-independent microtubule-binding region of Kinesin heavy chain are major functional domains for transport in the Drosophila germline. Development 2013; 141:176-86. [PMID: 24257625 PMCID: PMC3865757 DOI: 10.1242/dev.097592] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The major motor Kinesin-1 provides a key pathway for cell polarization through intracellular transport. Little is known about how Kinesin works in complex cellular surroundings. Several cargos associate with Kinesin via Kinesin light chain (KLC). However, KLC is not required for all Kinesin transport. A putative cargo-binding domain was identified in the C-terminal tail of fungal Kinesin heavy chain (KHC). The tail is conserved in animal KHCs and might therefore represent an alternative KLC-independent cargo-interacting region. By comprehensive functional analysis of the tail during Drosophila oogenesis we have gained an understanding of how KHC achieves specificity in its transport and how it is regulated. This is, to our knowledge, the first in vivo structural/functional analysis of the tail in animal Kinesins. We show that the tail is essential for all functions of KHC except Dynein transport, which is KLC dependent. These tail-dependent KHC activities can be functionally separated from one another by further characterizing domains within the tail. In particular, our data show the following. First, KHC is temporally regulated during oogenesis. Second, the IAK domain has an essential role distinct from its auto-inhibitory function. Third, lack of auto-inhibition in itself is not necessarily detrimental to KHC function. Finally, the ATP-independent microtubule-binding motif is required for cargo localization. These results stress that two unexpected highly conserved domains, namely the auto-inhibitory IAK and the auxiliary microtubule-binding motifs, are crucial for transport by Kinesin-1 and that, although not all cargos are conserved, their transport involves the most conserved domains of animal KHCs.
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Affiliation(s)
- Lucy S Williams
- University of Cambridge, Zoology Department, Downing Street, Cambridge CB2 3EJ, UK
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28
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Aoki T, Tomishige M, Ariga T. Single molecule FRET observation of kinesin-1's head-tail interaction on microtubule. Biophysics (Nagoya-shi) 2013; 9:149-59. [PMID: 27493553 PMCID: PMC4629677 DOI: 10.2142/biophysics.9.149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Accepted: 10/17/2013] [Indexed: 01/03/2023] Open
Abstract
Kinesin-1 (conventional kinesin) is a molecular motor that transports various cargo such as endoplasmic reticulum and mitochondria in cells. Its two head domains walk along microtubule by hydrolyzing ATP, while the tail domains at the end of the long stalk bind to the cargo. When a kinesin is not carrying cargo, its motility and ATPase activity is inhibited by direct interactions between the tail and head. However, the mechanism of this tail regulation is not well understood. Here, we apply single molecule fluorescence resonance energy transfer (smFRET) to observe this interaction in stalk-truncated kinesin. We found that kinesin with two tails forms a folding conformation and dissociates from microtubules, whereas kinesin with one tail remains bound to the micro-tubule and is immobile even in the presence of ATP. We further investigated the head-tail interaction as well as head-head coordination on the microtubule at various nucleotide conditions. From these results, we propose a two-step inhibition model for kinesin motility.
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Affiliation(s)
- Takahiro Aoki
- Department of Applied Physics, School of Engineering, the University of Tokyo, Tokyo, 113-8656, Japan
| | - Michio Tomishige
- Department of Applied Physics, School of Engineering, the University of Tokyo, Tokyo, 113-8656, Japan
| | - Takayuki Ariga
- Department of Applied Physics, School of Engineering, the University of Tokyo, Tokyo, 113-8656, Japan
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29
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A chimeric kinesin-1 head/kinesin-5 tail motor switches between diffusive and processive motility. Biophys J 2013; 104:432-41. [PMID: 23442865 DOI: 10.1016/j.bpj.2012.11.3810] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2012] [Revised: 09/27/2012] [Accepted: 11/16/2012] [Indexed: 01/12/2023] Open
Abstract
Homotetrameric kinesin-5 motors are essential for chromosome separation and assembly of the mitotic spindle. These kinesins bind between two microtubules (MTs) and slide them apart, toward the spindle poles. This process must be tightly regulated in mitosis. In in vitro assays, Eg5 moves diffusively on single MTs and switches to a directed mode between MTs. How allosteric communication between opposing motor domains works remains unclear, but kinesin-5 tail domains may be involved. Here we present a single-molecule fluorescence study of a tetrameric kinesin-1 head/kinesin-5 tail chimera, DK4mer. This motor exhibited fast processive motility on single MTs interrupted by pauses. Like Eg5, DK4mer diffused along MTs with ADP, and slid antiparallel MTs apart with ATP. In contrast to Eg5, diffusive and processive periods were clearly distinguishable. This allowed us to measure transition rates among states and for unbinding as a function of buffer ionic strength. These data, together with results from controls using tail-less dimers, indicate that there are two modes of interaction with MTs, separated by an energy barrier. This result suggests a scheme of motor regulation that involves switching between two bound states, possibly allosterically controlled by the opposing tetramer end. Such a scheme is likely to be relevant for the regulation of native kinesin-5 motors.
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30
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Khataee HR, Ibrahim MY. Modelling of internal architecture of kinesin nanomotor as a machine language. IET Nanobiotechnol 2013; 6:87-92. [PMID: 22894532 DOI: 10.1049/iet-nbt.2011.0062] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Kinesin is a protein-based natural nanomotor that transports molecular cargoes within cells by walking along microtubules. Kinesin nanomotor is considered as a bio-nanoagent which is able to sense the cell through its sensors (i.e. its heads and tail), make the decision internally and perform actions on the cell through its actuator (i.e. its motor domain). The study maps the agent-based architectural model of internal decision-making process of kinesin nanomotor to a machine language using an automata algorithm. The applied automata algorithm receives the internal agent-based architectural model of kinesin nanomotor as a deterministic finite automaton (DFA) model and generates a regular machine language. The generated regular machine language was acceptable by the architectural DFA model of the nanomotor and also in good agreement with its natural behaviour. The internal agent-based architectural model of kinesin nanomotor indicates the degree of autonomy and intelligence of the nanomotor interactions with its cell. Thus, our developed regular machine language can model the degree of autonomy and intelligence of kinesin nanomotor interactions with its cell as a language. Modelling of internal architectures of autonomous and intelligent bio-nanosystems as machine languages can lay the foundation towards the concept of bio-nanoswarms and next phases of the bio-nanorobotic systems development.
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Affiliation(s)
- H R Khataee
- Department of Computer Science, Universiti Putra Malaysia, Selangor, Malaysia.
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31
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Neurospora crassa NKIN2, a kinesin-3 motor, transports early endosomes and is required for polarized growth. EUKARYOTIC CELL 2013; 12:1020-32. [PMID: 23687116 DOI: 10.1128/ec.00081-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Biological motors are molecular nanomachines, which convert chemical energy into mechanical forces. The combination of mechanoenzymes with structural components, such as the cytoskeleton, enables eukaryotic cells to overcome entropy, generate molecular gradients, and establish polarity. Hyphae of filamentous fungi are among the most polarized cells, and polarity defects are most obvious. Here, we studied the role of the kinesin-3 motor, NKIN2, in Neurospora crassa. We found that NKIN2 localizes as fast-moving spots in the cytoplasm of mature hyphae. To test whether the spots represented early endosomes, the Rab5 GTPase YPT52 was used as an endosomal marker. NKIN2 colocalized with YPT52. Deletion of nkin2 caused strongly reduced endosomal movement. Combined, these results confirm the involvement of NKIN2 in early endosome transport. Introduction of a rigor mutation into NKIN2 labeled with green fluorescent protein (GFP) resulted in decoration of microtubules. Interestingly, NKIN2(rigor) was associated with a subpopulation of microtubules, as had been shown earlier for the Aspergillus nidulans orthologue UncA. Other kinesins did not show this specificity.
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32
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Wu G, Li GB, Dai B. Association of KIF6 variant with lipid level and angiographic coronary artery disease events risk in the Han Chinese population. Molecules 2012; 17:11269-80. [PMID: 23001387 PMCID: PMC6268110 DOI: 10.3390/molecules170911269] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 09/13/2012] [Accepted: 09/14/2012] [Indexed: 01/08/2023] Open
Abstract
KIF6 is a class of molecular motor from the kinesin superfamily. Recently, multiple large studies consisting mainly of Europeans have shown that KIF6 Trp719Arg SNP may be a new predictive factor for coronary artery disease (CAD) event risk. The allelic frequency distribution of rs20455 is different in various populations, yet studies among the Han population, one of the largest ethnic groups in the World, have not been conducted. This study is aimed to evaluate the association of KIF6 Trp719Arg variant with angiographic CAD and serum lipid levels in the Han population from northern China. In this case-controlled study, peripheral blood samples were collected from 356 patients and 568 controls of Han Chinese origin. Genotyping was performed by a high-resolution melting curve. The impact of rs20455 on CAD and non-fatal MI was evaluated in a dominant genetic model with stepwise multiple regression analysis. There were no significant differences of genotypes and allele frequency between angiographic CAD and control groups (p > 0.05); however, that of MI and non-MI subgroups were significant differences (p < 0.05). After adjusting for significant risk factors, angiographic CAD risk was not significantly increased in 719Arg allele carriers compared with non-carriers. Further analysis revealed that the non-fatal MI risk and triglyceride levels were significantly higher in 719Arg allele carriers than non-carriers. In conclusion, KIF6 719Arg allele was not an independent risk factor for angiographic CAD susceptibility in Han populations from northern China. However, it was associated with a significantly higher TG level, which may indicate an increased myocardial infarction risk in angiographic CAD patients.
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Affiliation(s)
| | - Gui-Bin Li
- The Forth Hospital of Jilin University, Changchun 130011, Jilin, China; (G.W.); (B.D.)
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33
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Three routes to suppression of the neurodegenerative phenotypes caused by kinesin heavy chain mutations. Genetics 2012; 192:173-83. [PMID: 22714410 DOI: 10.1534/genetics.112.140798] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Kinesin-1 is a motor protein that moves stepwise along microtubules by employing dimerized kinesin heavy chain (Khc) subunits that alternate cycles of microtubule binding, conformational change, and ATP hydrolysis. Mutations in the Drosophila Khc gene are known to cause distal paralysis and lethality preceded by the occurrence of dystrophic axon terminals, reduced axonal transport, organelle-filled axonal swellings, and impaired action potential propagation. Mutations in the equivalent human gene, Kif5A, result in similar problems that cause hereditary spastic paraplegia (HSP) and Charcot-Marie-Tooth type 2 (CMT2) distal neuropathies. By comparing the phenotypes and the complementation behaviors of a large set of Khc missense alleles, including one that is identical to a human Kif5A HSP allele, we identified three routes to suppression of Khc phenotypes: nutrient restriction, genetic background manipulation, and a remarkable intramolecular complementation between mutations known or likely to cause reciprocal changes in the rate of microtubule-stimulated ADP release by kinesin-1. Our results reveal the value of large-scale complementation analysis for gaining insight into protein structure-function relationships in vivo and point to possible paths for suppressing symptoms of HSP and related distal neuropathies.
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34
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Gerson-Gurwitz A, Thiede C, Movshovich N, Fridman V, Podolskaya M, Danieli T, Lakämper S, Klopfenstein DR, Schmidt CF, Gheber L. Directionality of individual kinesin-5 Cin8 motors is modulated by loop 8, ionic strength and microtubule geometry. EMBO J 2011; 30:4942-54. [PMID: 22101328 DOI: 10.1038/emboj.2011.403] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Accepted: 10/18/2011] [Indexed: 01/17/2023] Open
Abstract
Kinesin-5 motors fulfil essential roles in mitotic spindle morphogenesis and dynamics as slow, processive microtubule (MT) plus-end directed motors. The Saccharomyces cerevisiae kinesin-5 Cin8 was found, surprisingly, to switch directionality. Here, we have examined directionality using single-molecule fluorescence motility assays and live-cell microscopy. On spindles, Cin8 motors mostly moved slowly (∼25 nm/s) towards the midzone, but occasionally also faster (∼55 nm/s) towards the spindle poles. In vitro, individual Cin8 motors could be switched by ionic conditions from rapid (380 nm/s) and processive minus-end to slow plus-end motion on single MTs. At high ionic strength, Cin8 motors rapidly alternated directionalities between antiparallel MTs, while driving steady plus-end relative sliding. Between parallel MTs, plus-end motion was only occasionally observed. Deletion of the uniquely large insert in loop 8 of Cin8 induced bias towards minus-end motility and affected the ionic strength-dependent directional switching of Cin8 in vitro. The deletion mutant cells exhibited reduced midzone-directed motility and efficiency to support spindle elongation, indicating the importance of directionality control for the anaphase function of Cin8.
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35
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The spinal muscular atrophy mouse model, SMAΔ7, displays altered axonal transport without global neurofilament alterations. Acta Neuropathol 2011; 122:331-41. [PMID: 21681521 DOI: 10.1007/s00401-011-0848-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Revised: 05/31/2011] [Accepted: 06/05/2011] [Indexed: 12/11/2022]
Abstract
Spinal muscular atrophy (SMA) is a neurodegenerative disease resulting from decreased levels of survival motor neuron 1 (SMN1) protein. Reduced SMN1 levels are linked to pathology at neuromuscular junctions (NMJs), which includes decreased vesicle density and organization, decreased quantal release, increased endplate potential duration, and neurofilament (NF) accumulations. This work presents a first study towards defining molecular alterations that may lead to the development of NMJ pathology in SMA. Fast, anterograde transport of synaptic vesicle 2 (SV2-c) and synaptotagmin (Syt1) proteins was reduced 2 days prior to the observed decrease in synaptic vesicle density. Moreover, reduced accumulation of SV2-c or Syt1 was not due to reduced protein expression or reduced kinesin activity. Dynein levels were reduced at times that are consistent with NF accumulations at NMJs. Furthermore, NF distribution, from cell body to sciatic nerve, appeared normal in SMA∆7 mice. Taken together, these results suggest that reduced axonal transport may provide a mechanistic explanation for reduced synaptic vesicle density and concomitant synaptic transmission defects, while providing evidence that suggests NF accumulations result from local NMJ alterations to NFs.
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36
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Kaan HYK, Hackney DD, Kozielski F. The structure of the kinesin-1 motor-tail complex reveals the mechanism of autoinhibition. Science 2011; 333:883-5. [PMID: 21836017 PMCID: PMC3339660 DOI: 10.1126/science.1204824] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
When not transporting cargo, kinesin-1 is autoinhibited by binding of a tail region to the motor domains, but the mechanism of inhibition is unclear. We report the crystal structure of a motor domain dimer in complex with its tail domain at 2.2 angstroms and compare it with a structure of the motor domain alone at 2.7 angstroms. These structures indicate that neither an induced conformational change nor steric blocking is the cause of inhibition. Instead, the tail cross-links the motor domains at a second position, in addition to the coiled coil. This "double lockdown," by cross-linking at two positions, prevents the movement of the motor domains that is needed to undock the neck linker and release adenosine diphosphate. This autoinhibition mechanism could extend to some other kinesins.
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Affiliation(s)
- Hung Yi Kristal Kaan
- The Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, Scotland, UK
| | - David D. Hackney
- Department of Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, PA 15213, USA
| | - Frank Kozielski
- The Beatson Institute for Cancer Research, Switchback Road, Bearsden, Glasgow G61 1BD, Scotland, UK
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37
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Markus SM, Lee WL. Regulated offloading of cytoplasmic dynein from microtubule plus ends to the cortex. Dev Cell 2011; 20:639-51. [PMID: 21571221 DOI: 10.1016/j.devcel.2011.04.011] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 12/22/2010] [Accepted: 04/25/2011] [Indexed: 10/18/2022]
Abstract
Cytoplasmic dynein mediates spindle orientation from the cell cortex through interactions with astral microtubules, but neither the mechanism governing its cortical targeting nor the regulation thereof is well understood. Here we show that yeast dynein offloads from microtubule plus ends to the daughter cell cortex. Mutants with an engineered peptide inserted between the tail domain and the motor head retain wild-type motor activity but exhibit enhanced offloading and cortical targeting. Conversely, shortening the "neck" sequence between the tail and motor domains precludes offloading from the microtubule plus ends. Furthermore, chimeric mutants with mammalian dynein "neck" sequences rescue targeting and function. These findings provide direct support for an active microtubule-mediated delivery process that appears to be regulated by a conserved masking/unmasking mechanism.
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Affiliation(s)
- Steven M Markus
- Biology Department, University of Massachusetts Amherst, 221 Morrill South, 611 North Pleasant Street, Amherst, MA 01003, USA
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38
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Architecture and development of the Neurospora crassa hypha – a model cell for polarized growth. Fungal Biol 2011; 115:446-74. [PMID: 21640311 DOI: 10.1016/j.funbio.2011.02.008] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2010] [Revised: 02/08/2011] [Accepted: 02/09/2011] [Indexed: 11/20/2022]
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39
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Peña A, Ripoll-Rozada J, Zunzunegui S, Cabezón E, de la Cruz F, Arechaga I. Autoinhibitory regulation of TrwK, an essential VirB4 ATPase in type IV secretion systems. J Biol Chem 2011; 286:17376-82. [PMID: 21454654 DOI: 10.1074/jbc.m110.208942] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Type IV secretion systems (T4SS) mediate the transfer of DNA and protein substrates to target cells. TrwK, encoded by the conjugative plasmid R388, is a member of the VirB4 family, comprising the largest and most conserved proteins of T4SS. In a previous work we demonstrated that TrwK is able to hydrolyze ATP. Here, based on the structural homology of VirB4 proteins with the DNA-pumping ATPase TrwB coupling protein, we generated a series of variants of TrwK where fragments of the C-terminal domain were sequentially truncated. Surprisingly, the in vitro ATPase activity of these TrwK variants was much higher than that of the wild-type enzyme. Moreover, addition of a synthetic peptide containing the amino acid residues comprising this C-terminal region resulted in the specific inhibition of the TrwK variants lacking such domain. These results indicate that the C-terminal end of TrwK plays an important regulatory role in the functioning of the T4SS.
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Affiliation(s)
- Alejandro Peña
- Departamento de Biología Molecular, Universidad de Cantabria and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), UC-IDICAN-CSIC, Santander 39011, Spain
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40
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Moua P, Fullerton D, Serbus LR, Warrior R, Saxton WM. Kinesin-1 tail autoregulation and microtubule-binding regions function in saltatory transport but not ooplasmic streaming. Development 2011; 138:1087-92. [PMID: 21307100 DOI: 10.1242/dev.048645] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The N-terminal head domain of kinesin heavy chain (Khc) is well known for generating force for transport along microtubules in cytoplasmic organization processes during metazoan development, but the functions of the C-terminal tail are not clear. To address this, we studied the effects of tail mutations on mitochondria transport, determinant mRNA localization and cytoplasmic streaming in Drosophila. Our results show that two biochemically defined elements of the tail - the ATP-independent microtubule-binding sequence and the IAK autoinhibitory motif - are essential for development and viability. Both elements have positive functions in the axonal transport of mitochondria and determinant mRNA localization in oocytes, processes that are accomplished by biased saltatory movement of individual cargoes. Surprisingly, there were no indications that the IAK autoinhibitory motif acts as a general downregulator of Kinesin-1 in those processes. Time-lapse imaging indicated that neither tail region is needed for fast cytoplasmic streaming in oocytes, which is a non-saltatory bulk transport process driven solely by Kinesin-1. Thus, the Khc tail is not constitutively required for Kinesin-1 activation, force transduction or linkage to cargo. It might instead be crucial for more subtle elements of motor control and coordination in the stop-and-go movements of biased saltatory transport.
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Affiliation(s)
- Pangkong Moua
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
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41
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Kinesin's light chains inhibit the head- and microtubule-binding activity of its tail. Proc Natl Acad Sci U S A 2010; 107:11781-6. [PMID: 20547877 DOI: 10.1073/pnas.1005854107] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kinesin-1 is a microtubule-based motor comprising two heavy chains (KHCs) and two light chains (KLCs). Motor activity is precisely regulated to avoid futile ATP consumption and to ensure proper intracellular localization of kinesin-1 and its cargoes. The KHC tail inhibits ATPase activity by interacting with the enzymatic KHC heads, and the tail also binds microtubules. Here, we present a role for the KLCs in regulating both the head- and microtubule-binding activities of the kinesin-1 tail. We show that KLCs reduce the affinity of the head-tail interaction over tenfold and concomitantly repress the tail's regulatory activity. We also show that KLCs inhibit tail-microtubule binding by a separate mechanism. Inhibition of head-tail binding requires steric and electrostatic factors. Inhibition of tail-microtubule binding is largely electrostatic, pH dependent, and mediated partly by a highly negatively charged linker region between the KHC-interacting and cargo-binding domains of the KLCs. Our data support a model wherein KLCs promote activation of kinesin-1 for cargo transport by simultaneously suppressing tail-head and tail-microtubule interactions. KLC-mediated inhibition of tail-microtubule binding may also influence diffusional movement of kinesin-1 on microtubules, and kinesin-1's role in microtubule transport/sliding.
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Regulation of a heterodimeric kinesin-2 through an unprocessive motor domain that is turned processive by its partner. Proc Natl Acad Sci U S A 2010; 107:10460-5. [PMID: 20498083 DOI: 10.1073/pnas.1005177107] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Cilia are microtubule-based protrusions of the plasma membrane found on most eukaryotic cells. Their assembly is mediated through the conserved intraflagellar transport mechanism. One class of motor proteins involved in intraflagellar transport, kinesin-2, is unique among kinesin motors in that some of its members are composed of two distinct polypeptides. However, the biological reason for heterodimerization has remained elusive. Here we provide several interdependent reasons for the heterodimerization of the kinesin-2 motor KLP11/KLP20 of Caenorhabditis elegans cilia. One motor domain is unprocessive as a homodimer, but heterodimerization with a processive partner generates processivity. The "unprocessive" subunit is kept in this partnership as it mediates an asymmetric autoregulation of the motor activity. Finally, heterodimerization is necessary to bind KAP1, the in vivo link between motor and cargo.
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Cell-wide analysis of secretory granule dynamics in three dimensions in living pancreatic beta-cells: evidence against a role for AMPK-dependent phosphorylation of KLC1 at Ser517/Ser520 in glucose-stimulated insulin granule movement. Biochem Soc Trans 2010; 38:205-8. [PMID: 20074060 DOI: 10.1042/bst0380205] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Glucose-stimulated insulin secretion from pancreatic beta-cells requires the kinesin-1/Kif5B-mediated transport of insulin granules along microtubules. 5'-AMPK (5'-AMP-activated protein kinase) is a heterotrimeric serine/threonine kinase which is activated in beta-cells at low glucose concentrations, but inhibited as glucose levels increase. Active AMPK blocks glucose-stimulated insulin secretion and the recruitment of insulin granules to the cell surface, suggesting motor proteins may be targets for this kinase. While both kinesin-1/Kif5B and KLC1 (kinesin light chain-1) contain consensus AMPK phosphorylation sites (Thr(693) and Ser(520), respectively) only recombinant GST (glutathione transferase)-KLC1 was phosphorylated by purified AMPK in vitro. To test the hypothesis that phosphorylation at this site may modulate kinesin-1-mediated granule movement, we developed an approach to study the dynamics of all the resolvable granules within a cell in three dimensions. This cell-wide approach revealed that the number of longer excursions (>10 mum) increased significantly in response to elevated glucose concentration (30 versus 3 mM) in control MIN6 beta-cells. However, similar changes were seen in cells overexpressing wild-type KLC1, phosphomimetic (S517D/S520D) or non-phosphorylatable (S517A/S520A) mutants of KLC1. Thus, changes in the phosphorylation state of KLC1 at Ser(517)/Ser(520) seem unlikely to affect motor function.
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Morton AM, Cunningham AL, Diefenbach RJ. Kinesin-1 plays a role in transport of SNAP-25 to the plasma membrane. Biochem Biophys Res Commun 2009; 391:388-93. [PMID: 19913510 DOI: 10.1016/j.bbrc.2009.11.068] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Accepted: 11/09/2009] [Indexed: 01/12/2023]
Abstract
The cellular molecular motor kinesin-1 mediates the microtubule-dependent transport of a range of cargo. We have previously identified an interaction between the cargo-binding domain of kinesin-1 heavy chain KIF5B and the membrane-associated SNARE proteins SNAP-25 and SNAP-23. In this study we further defined the minimal SNAP-25 binding domain in KIF5B to residues 874-894. Overexpression of a fragment of KIF5B (residues 594-910) resulted in significant colocalization with SNAP-25 with resulting blockage of the trafficking of SNAP-25 to the periphery of cells. This indicates that kinesin-1 facilitates the transport of SNAP-25 containing vesicles as a prerequisite to SNAP-25 driven membrane fusion events.
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Affiliation(s)
- April M Morton
- Centre for Virus Research, Westmead Millennium Institute, The University of Sydney and Westmead Hospital, Westmead, NSW 2145, Australia
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Verhey KJ, Hammond JW. Traffic control: regulation of kinesin motors. Nat Rev Mol Cell Biol 2009; 10:765-77. [PMID: 19851335 DOI: 10.1038/nrm2782] [Citation(s) in RCA: 384] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Kinesins are a family of molecular motors that use the energy of ATP hydrolysis to move along the surface of, or destabilize, microtubule filaments. Much progress has been made in understanding the mechanics and functions of the kinesin motors that play important parts in cell division, cell motility, intracellular trafficking and ciliary function. How kinesins are regulated in cells to ensure the temporal and spatial fidelity of their microtubule-based activities is less well understood. Recent work has revealed molecular mechanisms that control kinesin autoinhibition and subsequent activation, binding to cargos and microtubule tracks, and localization at specific sites of action.
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Affiliation(s)
- Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109-2200, USA.
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Abstract
Intracellular transport is fundamental for cellular function, survival and morphogenesis. Kinesin superfamily proteins (also known as KIFs) are important molecular motors that directionally transport various cargos, including membranous organelles, protein complexes and mRNAs. The mechanisms by which different kinesins recognize and bind to specific cargos, as well as how kinesins unload cargo and determine the direction of transport, have now been identified. Furthermore, recent molecular genetic experiments have uncovered important and unexpected roles for kinesins in the regulation of such physiological processes as higher brain function, tumour suppression and developmental patterning. These findings open exciting new areas of kinesin research.
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Obstacles on the microtubule reduce the processivity of Kinesin-1 in a minimal in vitro system and in cell extract. Biophys J 2009; 96:3341-53. [PMID: 19383477 DOI: 10.1016/j.bpj.2009.01.015] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2008] [Revised: 12/19/2008] [Accepted: 01/08/2009] [Indexed: 11/23/2022] Open
Abstract
Inside cells, a multitude of molecular motors and other microtubule-associated proteins are expected to compete for binding to a limited number of binding sites available on microtubules. Little is known about how competition for binding sites affects the processivity of molecular motors and, therefore, cargo transport, organelle positioning, and microtubule organization, processes that all depend on the activity of more or less processive motors. Very few studies have been performed in the past to address this question directly. Most studies reported only minor effects of crowding on the velocity of motors. However, a controversy appears to exist regarding the effect of crowding on motor processivity. Here, we use single-molecule imaging of mGFP-labeled minimal dimeric kinesin-1 constructs in vitro to study the effects of competition on kinesin's processivity. For competitors, we use kinesin rigor mutants as static roadblocks, minimal wild-type kinesins as motile obstacles, and a cell extract as a complex mixture of microtubule-associated proteins. We find that mGFP-labeled kinesin-1 detaches prematurely from microtubules when it encounters obstacles, leading to a strong reduction of its processivity, a behavior that is largely independent of the type of obstacle used here. Kinesin has a low probability to wait briefly when encountering roadblocks. Our data suggest, furthermore, that kinesin can occasionally pass obstacles on the protofilament track.
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Wong YL, Dietrich KA, Naber N, Cooke R, Rice SE. The Kinesin-1 tail conformationally restricts the nucleotide pocket. Biophys J 2009; 96:2799-807. [PMID: 19348763 DOI: 10.1016/j.bpj.2008.11.069] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 11/07/2008] [Accepted: 11/25/2008] [Indexed: 11/19/2022] Open
Abstract
We have used electron paramagnetic resonance and fluorescence spectroscopy to study the interaction between the kinesin-1 head and its regulatory tail domain. The interaction between the tails and the enzymatically active heads has been shown to inhibit intrinsic and microtubule-stimulated ADP release. Here, we demonstrate that the probe mobility of two different spin-labeled nucleotide analogs in the kinesin-1 nucleotide pocket is restricted upon binding of the tail domain to kinesin-1 heads. This conformational restriction is distinct from the microtubule-induced changes in the nucleotide pocket. Unlike myosin V, this tail-induced restriction occurs independent of nucleotide state. We find that the head-tail interaction that causes the restriction only weakly stabilizes Mg(2+) in the nucleotide pocket. The conformational restriction also occurs when a tail construct containing a K922A point mutation is used. This mutation eliminates the tail's ability to inhibit ADP release, indicating that the tail does not inhibit nucleotide ejection from the pocket by simple steric hindrance. Together, our data suggest that the observed head-tail interaction serves as a scaffold to position K922 to exert its inhibitory effect, possibly by interacting with the nucleotide alpha/beta-phosphates in a manner analogous to the arginine finger regulators of some G proteins.
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Affiliation(s)
- Yao Liang Wong
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611, USA
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Dissecting colony development of Neurospora crassa using mRNA profiling and comparative genomics approaches. EUKARYOTIC CELL 2008; 7:1549-64. [PMID: 18676954 DOI: 10.1128/ec.00195-08] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Colony development, which includes hyphal extension, branching, anastomosis, and asexual sporulation, is a fundamental aspect of the life cycle of filamentous fungi; genetic mechanisms underlying these phenomena are poorly understood. We conducted transcriptional profiling during colony development of the model filamentous fungus Neurospora crassa, using 70-mer oligonucleotide microarrays. Relative mRNA expression levels were determined for six sections of defined age excised from a 27-h-old N. crassa colony. Functional category analysis showed that the expression of genes involved in cell membrane biosynthesis, polar growth, and cellular signaling was enriched at the periphery of the colony. The relative expression of genes involved in protein synthesis and energy production was enriched in the middle section of the colony, while sections of the colony undergoing asexual development (conidiogenesis) were enriched in expression of genes involved in protein/peptide degradation and unclassified proteins. A cross-examination of the N. crassa data set with a published data set of Aspergillus niger revealed shared patterns in the spatiotemporal regulation of gene orthologs during colony development. At present, less than 50% of genes in N. crassa have functional annotation, which imposes the chief limitation on data analysis. Using an evolutionary approach, we observed that the expression of phylogenetically conserved groups of genes was enriched in the middle section of an N. crassa colony whereas expression of genes unique to euascomycete species and of N. crassa orphan genes was enriched at the colony periphery and in the older, conidiating sections of a fungal colony.
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