1
|
Xie P. Modeling study of kinesin-13 MCAK microtubule depolymerase. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2024; 53:339-354. [PMID: 39093405 DOI: 10.1007/s00249-024-01718-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Accepted: 07/18/2024] [Indexed: 08/04/2024]
Abstract
Mitotic centromere-associated kinesin (MCAK) motor protein is a typical member of the kinesin-13 family, which can depolymerize microtubules from both plus and minus ends. A critical issue for the MCAK motor is how it performs the depolymerase activity. To address the issue, the pathway of the MCAK motor moving on microtubules and depolymerizing the microtubules is presented here. On the basis of the pathway, the dynamics of both the wild-type and mutant MCAK motors is studied theoretically, which include the full-length MCAK, the full-length MCAK with mutations in the α4-helix of the motor domain, the mutant full-length MCAK with a neutralized neck, the monomeric MCAK and the mutant monomeric MCAK with a neutralized neck. The studies show that a single dimeric MCAK motor can depolymerize microtubules in a processive manner, with either one tubulin or two tubulins being removed per times. The theoretical results are in agreement with the available experimental data. Moreover, predicted results are provided.
Collapse
Affiliation(s)
- Ping Xie
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
| |
Collapse
|
2
|
Xie P. A model of microtubule depolymerization by kinesin-8 motor proteins. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 141:87-122. [PMID: 38960488 DOI: 10.1016/bs.apcsb.2023.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The dimeric kinesin-8 motors have the biological function of depolymerizing microtubules (MTs) from the plus end. However, the molecular mechanism of the depolymerization promoted by the kinesin-8 motors is still undetermined. Here, a model is proposed for the MT depolymerization by the kinesin-8 motors. Based on the model, the dynamics of depolymerization in the presence of the single motor at the MT plus end under no load and under load on the motor is studied theoretically. The dynamics of depolymerization in the presence of multiple motors at the MT plus end is also analyzed. The theoretical results explain well the available experimental data. The studies can also be applicable to other families of kinesin motors such as kinesin-13 mitotic centromere-associated kinesin motors that have the ability to depolymerize MTs.
Collapse
Affiliation(s)
- Ping Xie
- Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Science, Beijing, P.R. China.
| |
Collapse
|
3
|
Atomic force microscopy reveals distinct protofilament-scale structural dynamics in depolymerizing microtubule arrays. Proc Natl Acad Sci U S A 2022; 119:2115708119. [PMID: 35101922 PMCID: PMC8812519 DOI: 10.1073/pnas.2115708119] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/09/2021] [Indexed: 12/01/2022] Open
Abstract
One cannot help but marvel at the precise organization of microtubule polymers in cellular structures such as the axoneme and the spindle. However, our understanding of the biochemical mechanisms that sculpt these arrays comes largely from in vitro experiments with a small number (one or two) of microtubules. This is somewhat akin to studying the architecture of multilane highways by studying one-lane streets. Here, we directly visualize depolymerizing microtubule arrays at individual microtubule and protofilament resolution using atomic force microscopy. Our results reveal differences in microtubule depolymerase activity and provide insights into how these differences in enzymatic activity on the nanometer scale can result in the differential remodeling of multimicrotubule arrays on the micron-length scale. The dynamic reorganization of microtubule-based cellular structures, such as the spindle and the axoneme, fundamentally depends on the dynamics of individual polymers within multimicrotubule arrays. A major class of enzymes implicated in both the complete demolition and fine size control of microtubule-based arrays are depolymerizing kinesins. How different depolymerases differently remodel microtubule arrays is poorly understood. A major technical challenge in addressing this question is that existing optical or electron-microscopy methods lack the spatial-temporal resolution to observe the dynamics of individual microtubules within larger arrays. Here, we use atomic force microscopy (AFM) to image depolymerizing arrays at single-microtubule and protofilament resolution. We discover previously unseen modes of microtubule array destabilization by conserved depolymerases. We find that the kinesin-13 MCAK mediates asynchronous protofilament depolymerization and lattice-defect propagation, whereas the kinesin-8 Kip3p promotes synchronous protofilament depolymerization. Unexpectedly, MCAK can depolymerize the highly stable axonemal doublets, but Kip3p cannot. We propose that distinct protofilament-level activities underlie the functional dichotomy of depolymerases, resulting in either large-scale destabilization or length regulation of microtubule arrays. Our work establishes AFM as a powerful strategy to visualize microtubule dynamics within arrays and reveals how nanometer-scale substrate specificity leads to differential remodeling of micron-scale cytoskeletal structures.
Collapse
|
4
|
Cason SE, Carman PJ, Van Duyne C, Goldsmith J, Dominguez R, Holzbaur ELF. Sequential dynein effectors regulate axonal autophagosome motility in a maturation-dependent pathway. J Cell Biol 2021; 220:212171. [PMID: 34014261 PMCID: PMC8142281 DOI: 10.1083/jcb.202010179] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 03/31/2021] [Accepted: 04/28/2021] [Indexed: 12/14/2022] Open
Abstract
Autophagy is a degradative pathway required to maintain homeostasis. Neuronal autophagosomes form constitutively at the axon terminal and mature via lysosomal fusion during dynein-mediated transport to the soma. How the dynein–autophagosome interaction is regulated is unknown. Here, we identify multiple dynein effectors on autophagosomes as they transit along the axons of primary neurons. In the distal axon, JIP1 initiates autophagosomal transport. Autophagosomes in the mid-axon require HAP1 and Huntingtin. We find that HAP1 is a dynein activator, binding the dynein–dynactin complex via canonical and noncanonical interactions. JIP3 is on most axonal autophagosomes, but specifically regulates the transport of mature autolysosomes. Inhibiting autophagosomal transport disrupts maturation, and inhibiting autophagosomal maturation perturbs the association and function of dynein effectors; thus, maturation and transport are tightly linked. These results reveal a novel maturation-based dynein effector handoff on neuronal autophagosomes that is key to motility, cargo degradation, and the maintenance of axonal health.
Collapse
Affiliation(s)
- Sydney E Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA.,Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA
| | - Peter J Carman
- Department of Physiology, University of Pennsylvania, Philadelphia, PA.,Biochemistry and Molecular Biophysics Graduate Group, University of Pennsylvania, Philadelphia, PA
| | - Claire Van Duyne
- Department of Physiology, University of Pennsylvania, Philadelphia, PA.,Vagelos Scholars Program, University of Pennsylvania, Philadelphia, PA
| | - Juliet Goldsmith
- Department of Physiology, University of Pennsylvania, Philadelphia, PA
| | - Roberto Dominguez
- Department of Physiology, University of Pennsylvania, Philadelphia, PA.,Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA.,Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
5
|
Lee IG, Cason SE, Alqassim SS, Holzbaur ELF, Dominguez R. A tunable LIC1-adaptor interaction modulates dynein activity in a cargo-specific manner. Nat Commun 2020; 11:5695. [PMID: 33173051 PMCID: PMC7655957 DOI: 10.1038/s41467-020-19538-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/16/2020] [Indexed: 01/07/2023] Open
Abstract
Cytoplasmic dynein-1 (dynein) is the motor responsible for most retrograde transport of cargoes along microtubules in eukaryotic cells, including organelles, mRNA and viruses. Cargo selectivity and activation of processive motility depend on a group of so-called "activating adaptors" that link dynein to its general cofactor, dynactin, and cargoes. The mechanism by which these adaptors regulate dynein transport is poorly understood. Here, based on crystal structures, quantitative binding studies, and in vitro motility assays, we show that BICD2, CRACR2a, and HOOK3, representing three subfamilies of unrelated adaptors, interact with the same amphipathic helix of the dynein light intermediate chain-1 (LIC1). While the hydrophobic character of the interaction is conserved, the three adaptor subfamilies use different folds (coiled-coil, EF-hand, HOOK domain) and different surface contacts to bind the LIC1 helix with affinities ranging from 1.5 to 15.0 μM. We propose that a tunable LIC1-adaptor interaction modulates dynein's motility in a cargo-specific manner.
Collapse
Affiliation(s)
- In-Gyun Lee
- grid.25879.310000 0004 1936 8972Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA ,grid.35541.360000000121053345Present Address: Korea Institute of Science and Technology (KIST), 5 Hwarangro 14-Gil, Seongbuk-Gu, Seoul, 02792 Republic of Korea
| | - Sydney E. Cason
- grid.25879.310000 0004 1936 8972Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA ,grid.25879.310000 0004 1936 8972Neuroscience Graduate Group, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Saif S. Alqassim
- grid.25879.310000 0004 1936 8972Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA ,Present Address: College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
| | - Erika L. F. Holzbaur
- grid.25879.310000 0004 1936 8972Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA ,grid.25879.310000 0004 1936 8972Neuroscience Graduate Group, Biomedical Graduate Studies, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA
| | - Roberto Dominguez
- grid.25879.310000 0004 1936 8972Department of Physiology and Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104 USA
| |
Collapse
|
6
|
Wagenbach M, Vicente JJ, Ovechkina Y, Domnitz S, Wordeman L. Functional characterization of MCAK/Kif2C cancer mutations using high-throughput microscopic analysis. Mol Biol Cell 2020; 31:580-588. [PMID: 31746663 PMCID: PMC7202071 DOI: 10.1091/mbc.e19-09-0503] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The microtubule (MT)-depolymerizing activity of MCAK/Kif2C can be quantified by expressing the motor in cultured cells and measuring tubulin fluorescence levels after enough hours have passed to allow tubulin autoregulation to proceed. This method allows us to score the impact of point mutations within the motor domain. We found that, despite their distinctly different activities, many mutations that impact transport kinesins also impair MCAK/Kif2C's depolymerizing activity. We improved our workflow using CellProfiler to significantly speed up the imaging and analysis of transfected cells. This allowed us to rapidly interrogate a number of MCAK/Kif2C motor domain mutations documented in the cancer database cBioPortal. We found that a large proportion of these mutations adversely impact the motor. Using green fluorescent protein-FKBP-MCAK CRISPR cells we found that one deleterious hot-spot mutation increased chromosome instability in a wild-type (WT) background, suggesting that such mutants have the potential to promote tumor karyotype evolution. We also found that increasing WT MCAK/Kif2C protein levels over that of endogenous MCAK/Kif2C similarly increased chromosome instability. Thus, endogenous MCAK/Kif2C activity in normal cells is tuned to a mean level to achieve maximal suppression of chromosome instability.
Collapse
Affiliation(s)
- Mike Wagenbach
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Juan Jesus Vicente
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Yulia Ovechkina
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Sarah Domnitz
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Linda Wordeman
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| |
Collapse
|
7
|
Qu Y, Hahn I, Lees M, Parkin J, Voelzmann A, Dorey K, Rathbone A, Friel CT, Allan VJ, Okenve-Ramos P, Sanchez-Soriano N, Prokop A. Efa6 protects axons and regulates their growth and branching by inhibiting microtubule polymerisation at the cortex. eLife 2019; 8:e50319. [PMID: 31718774 PMCID: PMC6884004 DOI: 10.7554/elife.50319] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 11/06/2019] [Indexed: 12/12/2022] Open
Abstract
Cortical collapse factors affect microtubule (MT) dynamics at the plasma membrane. They play important roles in neurons, as suggested by inhibition of axon growth and regeneration through the ARF activator Efa6 in C. elegans, and by neurodevelopmental disorders linked to the mammalian kinesin Kif21A. How cortical collapse factors influence axon growth is little understood. Here we studied them, focussing on the function of Drosophila Efa6 in experimentally and genetically amenable fly neurons. First, we show that Drosophila Efa6 can inhibit MTs directly without interacting molecules via an N-terminal 18 amino acid motif (MT elimination domain/MTED) that binds tubulin and inhibits microtubule growth in vitro and cells. If N-terminal MTED-containing fragments are in the cytoplasm they abolish entire microtubule networks of mouse fibroblasts and whole axons of fly neurons. Full-length Efa6 is membrane-attached, hence primarily blocks MTs in the periphery of fibroblasts, and explorative MTs that have left axonal bundles in neurons. Accordingly, loss of Efa6 causes an increase of explorative MTs: in growth cones they enhance axon growth, in axon shafts they cause excessive branching, as well as atrophy through perturbations of MT bundles. Efa6 over-expression causes the opposite phenotypes. Taken together, our work conceptually links molecular and sub-cellular functions of cortical collapse factors to axon growth regulation and reveals new roles in axon branching and in the prevention of axonal atrophy. Furthermore, the MTED delivers a promising tool that can be used to inhibit MTs in a compartmentalised fashion when fusing it to specifically localising protein domains.
Collapse
Affiliation(s)
- Yue Qu
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Ines Hahn
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Meredith Lees
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Jill Parkin
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - André Voelzmann
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Karel Dorey
- Faculty of Biology, Medicine and Health, School of Medical SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Alex Rathbone
- School of Life Sciences, Faculty of Medicine and Health SciencesThe University of NottinghamNottinghamUnited Kingdom
| | - Claire T Friel
- School of Life Sciences, Faculty of Medicine and Health SciencesThe University of NottinghamNottinghamUnited Kingdom
| | - Victoria J Allan
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| | - Pilar Okenve-Ramos
- Department of Cellular and Molecular Physiology,Institute of Translational MedicineUniversity of LiverpoolLiverpoolUnited Kingdom
| | - Natalia Sanchez-Soriano
- Department of Cellular and Molecular Physiology,Institute of Translational MedicineUniversity of LiverpoolLiverpoolUnited Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biological SciencesThe University of ManchesterManchesterUnited Kingdom
| |
Collapse
|
8
|
Diaz P, Horne E, Xu C, Hamel E, Wagenbach M, Petrov RR, Uhlenbruck B, Haas B, Hothi P, Wordeman L, Gussio R, Stella N. Modified carbazoles destabilize microtubules and kill glioblastoma multiform cells. Eur J Med Chem 2018; 159:74-89. [PMID: 30268825 DOI: 10.1016/j.ejmech.2018.09.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 09/07/2018] [Accepted: 09/09/2018] [Indexed: 11/26/2022]
Abstract
Small molecules that target microtubules (MTs) represent promising therapeutics to treat certain types of cancer, including glioblastoma multiform (GBM). We synthesized modified carbazoles and evaluated their antitumor activity in GBM cells in culture. Modified carbazoles with an ethyl moiety linked to the nitrogen of the carbazole and a carbonyl moiety linked to distinct biaromatic rings exhibited remarkably different killing activities in human GBM cell lines and patient-derived GBM cells, with IC50 values from 67 to >10,000 nM. Measures of the activity of modified carbazoles with tubulin and microtubules coupled to molecular docking studies show that these compounds bind to the colchicine site of tubulin in a unique low interaction space that inhibits tubulin assembly. The modified carbazoles reported here represent novel chemical tools to better understand how small molecules disrupt MT functions and kill devastating cancers such as GBM.
Collapse
Affiliation(s)
- Philippe Diaz
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA; DermaXon LLC, 32 Campus Drive, Missoula, MT, 59812, USA.
| | - Eric Horne
- Stella Therapeutics, Inc., Pacific Northwest Research Institute, 720 Broadway, Seattle, WA, 98122, USA
| | - Cong Xu
- Department of Pharmacology (CX, BH and NS), Department of Physiology and Biophysics (MW and LW), Department of Psychiatry and Behavioral Sciences (NS), The University of Washington, Seattle, WA, 98195, USA
| | - Ernest Hamel
- Screening Technologies Branch (EH) and Computational Drug Development Group (RG), Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA
| | - Michael Wagenbach
- Department of Pharmacology (CX, BH and NS), Department of Physiology and Biophysics (MW and LW), Department of Psychiatry and Behavioral Sciences (NS), The University of Washington, Seattle, WA, 98195, USA
| | - Ravil R Petrov
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Benjamin Uhlenbruck
- Department of Biomedical and Pharmaceutical Sciences, The University of Montana, 32 Campus Drive, Missoula, MT, 59812, USA
| | - Brian Haas
- Department of Pharmacology (CX, BH and NS), Department of Physiology and Biophysics (MW and LW), Department of Psychiatry and Behavioral Sciences (NS), The University of Washington, Seattle, WA, 98195, USA
| | - Parvinder Hothi
- Ivy Center for Advance Brain Tumor Treatment, Swedish Neuroscience Institute, 550 17th Ave, Seattle, WA, 98122, USA
| | - Linda Wordeman
- Department of Pharmacology (CX, BH and NS), Department of Physiology and Biophysics (MW and LW), Department of Psychiatry and Behavioral Sciences (NS), The University of Washington, Seattle, WA, 98195, USA
| | - Rick Gussio
- Screening Technologies Branch (EH) and Computational Drug Development Group (RG), Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, 21702, USA
| | - Nephi Stella
- Stella Therapeutics, Inc., Pacific Northwest Research Institute, 720 Broadway, Seattle, WA, 98122, USA; Department of Pharmacology (CX, BH and NS), Department of Physiology and Biophysics (MW and LW), Department of Psychiatry and Behavioral Sciences (NS), The University of Washington, Seattle, WA, 98195, USA.
| |
Collapse
|
9
|
Ternary complex of Kif2A-bound tandem tubulin heterodimers represents a kinesin-13-mediated microtubule depolymerization reaction intermediate. Nat Commun 2018; 9:2628. [PMID: 29980677 PMCID: PMC6035175 DOI: 10.1038/s41467-018-05025-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 06/11/2018] [Indexed: 12/22/2022] Open
Abstract
Kinesin-13 proteins are major microtubule (MT) regulatory factors that catalyze removal of tubulin subunits from MT ends. The class-specific “neck” and loop 2 regions of these motors are required for MT depolymerization, but their contributing roles are still unresolved because their interactions with MT ends have not been observed directly. Here we report the crystal structure of a catalytically active kinesin-13 monomer (Kif2A) in complex with two bent αβ-tubulin heterodimers in a head-to-tail array, providing a view of these interactions. The neck of Kif2A binds to one tubulin dimer and the motor core to the other, guiding insertion of the KVD motif of loop 2 in between them. AMPPNP-bound Kif2A can form stable complexes with tubulin in solution and trigger MT depolymerization. We also demonstrate the importance of the neck in modulating ATP turnover and catalytic depolymerization of MTs. These results provide mechanistic insights into the catalytic cycles of kinesin-13. The kinesin-13 family of microtubule (MT) depolymerases are major regulators of MT dynamics. Here the authors provide insights into the MT depolymerization mechanism by solving the crystal structure of a kinesin-13 monomer (Kif2A) in complex with two bent αβ-tubulin heterodimers.
Collapse
|
10
|
Mechanism of Catalytic Microtubule Depolymerization via KIF2-Tubulin Transitional Conformation. Cell Rep 2018; 20:2626-2638. [PMID: 28903043 DOI: 10.1016/j.celrep.2017.08.067] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/31/2017] [Accepted: 08/18/2017] [Indexed: 11/23/2022] Open
Abstract
Microtubules (MTs) are dynamic structures that are fundamental for cell morphogenesis and motility. MT-associated motors work efficiently to perform their functions. Unlike other motile kinesins, KIF2 catalytically depolymerizes MTs from the peeled protofilament end during ATP hydrolysis. However, the detailed mechanism by which KIF2 drives processive MT depolymerization remains unknown. To elucidate the catalytic mechanism, the transitional KIF2-tubulin complex during MT depolymerization was analyzed through multiple methods, including atomic force microscopy, size-exclusion chromatography, multi-angle light scattering, small-angle X-ray scattering, analytical ultracentrifugation, and mass spectrometry. The analyses outlined the conformation in which one KIF2core domain binds tightly to two tubulin dimers in the middle pre-hydrolysis state during ATP hydrolysis, a process critical for catalytic MT depolymerization. The X-ray crystallographic structure of the KIF2core domain displays the activated conformation that sustains the large KIF2-tubulin 1:2 complex.
Collapse
|
11
|
Arellano-Santoyo H, Geyer EA, Stokasimov E, Chen GY, Su X, Hancock W, Rice LM, Pellman D. A Tubulin Binding Switch Underlies Kip3/Kinesin-8 Depolymerase Activity. Dev Cell 2017; 42:37-51.e8. [PMID: 28697331 DOI: 10.1016/j.devcel.2017.06.011] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 05/22/2017] [Accepted: 06/09/2017] [Indexed: 02/04/2023]
Abstract
Kinesin-8 motors regulate the size of microtubule structures, using length-dependent accumulation at the plus end to preferentially disassemble long microtubules. Despite extensive study, the kinesin-8 depolymerase mechanism remains under debate. Here, we provide evidence for an alternative, tubulin curvature-sensing model of microtubule depolymerization by the budding yeast kinesin-8, Kip3. Kinesin-8/Kip3 uses ATP hydrolysis, like other kinesins, for stepping on the microtubule lattice, but at the plus end Kip3 undergoes a switch: its ATPase activity is suppressed when it binds tightly to the curved conformation of tubulin. This prolongs plus-end binding, stabilizes protofilament curvature, and ultimately promotes microtubule disassembly. The tubulin curvature-sensing model is supported by our identification of Kip3 structural elements necessary and sufficient for plus-end binding and depolymerase activity, as well as by the identification of an α-tubulin residue specifically required for the Kip3-curved tubulin interaction. Together, these findings elucidate a major regulatory mechanism controlling the size of cellular microtubule structures.
Collapse
Affiliation(s)
- Hugo Arellano-Santoyo
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA
| | | | - Ema Stokasimov
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA
| | - Geng-Yuan Chen
- Department of Biomedical Engineering, Penn State University, University Park, PA 16802, USA
| | - Xiaolei Su
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA 94143, USA
| | - William Hancock
- Department of Biomedical Engineering, Penn State University, University Park, PA 16802, USA
| | - Luke M Rice
- Department of Biophysics, UT Southwestern, Dallas, TX 75390, USA
| | - David Pellman
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Pediatric Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Cell Biology, Harvard Medical School, Boston, MA 02215, USA.
| |
Collapse
|
12
|
Wordeman L, Decarreau J, Vicente JJ, Wagenbach M. Divergent microtubule assembly rates after short- versus long-term loss of end-modulating kinesins. Mol Biol Cell 2016; 27:1300-9. [PMID: 26912793 PMCID: PMC4831883 DOI: 10.1091/mbc.e15-11-0803] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 02/16/2016] [Indexed: 11/11/2022] Open
Abstract
Depletion of microtubule (MT) regulators can initiate stable alterations in MT assembly rates that affect chromosome instability and mitotic spindle function, but the manner by which cellular MT assembly rates can stably increase or decrease is not understood. To investigate this phenomenon, we measured the response of microtubule assembly to both rapid and long-term loss of MT regulators MCAK/Kif2C and Kif18A. Depletion of MCAK/Kif2C by siRNA stably decreases MT assembly rates in mitotic spindles, whereas depletion of Kif18A stably increases rates of assembly. Surprisingly, this is not phenocopied by rapid rapamycin-dependent relocalization of MCAK/Kif2C and Kif18A to the plasma membrane. Instead, this treatment yields opposite affects on MT assembly. Rapidly increased MT assembly rates are balanced by a decrease in nucleated microtubules, whereas nucleation appears to be maximal and limiting for decreased MT assembly rates and also for long-term treatments. We measured amplified tubulin synthesis during long-term depletion of MT regulators and hypothesize that this is the basis for different phenotypes arising from long-term versus rapid depletion of MT regulators.
Collapse
Affiliation(s)
- Linda Wordeman
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Justin Decarreau
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Juan Jesus Vicente
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| | - Michael Wagenbach
- Department of Physiology and Biophysics, University of Washington School of Medicine, Seattle, WA 98195
| |
Collapse
|
13
|
Wang W, Shen T, Guerois R, Zhang F, Kuerban H, Lv Y, Gigant B, Knossow M, Wang C. New Insights into the Coupling between Microtubule Depolymerization and ATP Hydrolysis by Kinesin-13 Protein Kif2C. J Biol Chem 2015; 290:18721-31. [PMID: 26055718 DOI: 10.1074/jbc.m115.646919] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Indexed: 11/06/2022] Open
Abstract
Kinesin-13 proteins depolymerize microtubules in an ATP hydrolysis-dependent manner. The coupling between these two activities remains unclear. Here, we first studied the role of the kinesin-13 subfamily-specific loop 2 and of the KVD motif at the tip of this loop. Shortening the loop, the lysine/glutamate interchange and the additional Val to Ser substitution all led to Kif2C mutants with decreased microtubule-stimulated ATPase and impaired depolymerization capability. We rationalized these results based on a structural model of the Kif2C-ATP-tubulin complex derived from the recently determined structures of kinesin-1 bound to tubulin. In this model, upon microtubule binding Kif2C undergoes a conformational change governed in part by the interaction of the KVD motif with the tubulin interdimer interface. Second, we mutated to an alanine the conserved glutamate residue of the switch 2 nucleotide binding motif. This mutation blocks motile kinesins in a post-conformational change state and inhibits ATP hydrolysis. This Kif2C mutant still depolymerized microtubules and yielded complexes of one Kif2C with two tubulin heterodimers. These results demonstrate that the structural change of Kif2C-ATP upon binding to microtubule ends is sufficient for tubulin release, whereas ATP hydrolysis is not required. Overall, our data suggest that the conformation reached by kinesin-13s upon tubulin binding is similar to that of tubulin-bound, ATP-bound, motile kinesins but that this conformation is adapted to microtubule depolymerization.
Collapse
Affiliation(s)
- Weiyi Wang
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China, the Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette 91198, France, and
| | - Ting Shen
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China
| | - Raphael Guerois
- the Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette 91198, France, and the From CEA, Institut de Biologie et de la Technologies de Saclay (iBiTecS), Gif-sur-Yvette 91191, France
| | - Fuming Zhang
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China
| | - Hureshitanmu Kuerban
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China
| | - Yuncong Lv
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China
| | - Benoît Gigant
- the Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette 91198, France, and
| | - Marcel Knossow
- the Institute for Integrative Biology of the Cell, CEA, CNRS, Université Paris-Sud, Gif-sur-Yvette 91198, France, and
| | - Chunguang Wang
- From the Institute of Protein Research, Tongji University, Shanghai 200092, China,
| |
Collapse
|
14
|
Cochran JC. Kinesin Motor Enzymology: Chemistry, Structure, and Physics of Nanoscale Molecular Machines. Biophys Rev 2015; 7:269-299. [PMID: 28510227 DOI: 10.1007/s12551-014-0150-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Accepted: 11/16/2014] [Indexed: 11/25/2022] Open
Abstract
Molecular motors are enzymes that convert chemical potential energy into controlled kinetic energy for mechanical work inside cells. Understanding the biophysics of these motors is essential for appreciating life as well as apprehending diseases that arise from motor malfunction. This review focuses on kinesin motor enzymology with special emphasis on the literature that reports the chemistry, structure and physics of several different kinesin superfamily members.
Collapse
Affiliation(s)
- J C Cochran
- Department of Molecular & Cellular Biochemistry, Indiana University, Simon Hall Room 405C, 212 S. Hawthorne Dr., Bloomington, IN, 47405, USA.
| |
Collapse
|
15
|
Cross RA, McAinsh A. Prime movers: the mechanochemistry of mitotic kinesins. Nat Rev Mol Cell Biol 2014; 15:257-71. [PMID: 24651543 DOI: 10.1038/nrm3768] [Citation(s) in RCA: 138] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mitotic spindles are self-organizing protein machines that harness teams of multiple force generators to drive chromosome segregation. Kinesins are key members of these force-generating teams. Different kinesins walk directionally along dynamic microtubules, anchor, crosslink, align and sort microtubules into polarized bundles, and influence microtubule dynamics by interacting with microtubule tips. The mechanochemical mechanisms of these kinesins are specialized to enable each type to make a specific contribution to spindle self-organization and chromosome segregation.
Collapse
Affiliation(s)
- Robert A Cross
- Warwick Medical School, Gibbet Hill, Coventry CV4 7AL, UK
| | - Andrew McAinsh
- Warwick Medical School, Gibbet Hill, Coventry CV4 7AL, UK
| |
Collapse
|
16
|
Ems-McClung SC, Hainline SG, Devare J, Zong H, Cai S, Carnes SK, Shaw SL, Walczak CE. Aurora B inhibits MCAK activity through a phosphoconformational switch that reduces microtubule association. Curr Biol 2013; 23:2491-9. [PMID: 24291095 DOI: 10.1016/j.cub.2013.10.054] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/12/2013] [Accepted: 10/21/2013] [Indexed: 01/26/2023]
Abstract
BACKGROUND Proper spindle assembly and chromosome segregation rely on precise microtubule dynamics, which are governed in part by the kinesin-13 MCAK. MCAK microtubule depolymerization activity is inhibited by Aurora B-dependent phosphorylation, but the mechanism of this inhibition is not understood. RESULTS Here, we develop the first Förster resonance energy transfer (FRET)-based biosensor for MCAK and show that MCAK in solution exists in a closed conformation mediated by an interaction between the C-terminal domain (CT) and the neck. Using fluorescence lifetime imaging (FLIM) we show that MCAK bound to microtubule ends is closed relative to MCAK associated with the microtubule lattice. Aurora B phosphorylation at S196 in the neck opens MCAK conformation and diminishes the interaction between the CT and the neck. Using FLIM and TIRF imaging, we find that changes in MCAK conformation are associated with a decrease in MCAK affinity for the microtubule. CONCLUSIONS Unlike motile kinesins, which are open when doing work, the high-affinity binding state for microtubule-depolymerizing kinesins is in a closed conformation. Phosphorylation switches MCAK conformation, which inhibits its ability to interact with microtubules and reduces its microtubule depolymerization activity. This work shows that the conformational model proposed for regulating kinesin activity is not universal and that microtubule-depolymerizing kinesins utilize a distinct conformational mode to regulate affinity for the microtubule, thus controlling their catalytic efficiency. Furthermore, our work provides a mechanism by which the robust microtubule depolymerization activity of kinesin-13s can be rapidly modulated to control cellular microtubule dynamics.
Collapse
Affiliation(s)
| | - Sarah G Hainline
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Jenna Devare
- Department of Cellular and Molecular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | - Hailing Zong
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Shang Cai
- Department of Cellular and Molecular Biochemistry, Indiana University, Bloomington, IN 47405, USA
| | | | - Sidney L Shaw
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Claire E Walczak
- Medical Sciences, Indiana University, Bloomington, IN 47405, USA.
| |
Collapse
|
17
|
Abstract
The microtubule (MT) cytoskeleton supports a broad range of cellular functions, from providing tracks for intracellular transport, to supporting movement of cilia and flagella, to segregating chromosomes in mitosis. These functions are facilitated by the organizational and dynamic plasticity of MT networks. An important class of enzymes that alters MT dynamics is the depolymerizing kinesin-like proteins, which use their catalytic activities to regulate MT end dynamics. In this review, we discuss four topics surrounding these MT-depolymerizing kinesins. We provide a historical overview of studies focused on these motors and discuss their phylogeny. In the second half, we discuss their enzymology and biophysics and give an overview of their known cellular functions. This discussion highlights the fact that MT-depolymerizing kinesins exhibit a diverse range of design principles, which in turn increases their functional versatility in cells.
Collapse
Affiliation(s)
- Claire E Walczak
- Medical Sciences, Indiana University, Bloomington, Indiana 47405;
| | | | | |
Collapse
|
18
|
Altered nucleotide-microtubule coupling and increased mechanical output by a kinesin mutant. PLoS One 2012; 7:e47148. [PMID: 23077560 PMCID: PMC3473065 DOI: 10.1371/journal.pone.0047148] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Accepted: 09/12/2012] [Indexed: 11/19/2022] Open
Abstract
Kinesin motors hydrolyze ATP to produce force and do work in the cell – how the motors do this is not fully understood, but is thought to depend on the coupling of ATP hydrolysis to microtubule binding by the motor. Transmittal of conformational changes from the microtubule- to the nucleotide-binding site has been proposed to involve the central β-sheet, which could undergo large structural changes important for force production. We show here that mutation of an invariant residue in loop L7 of the central β-sheet of the Drosophila kinesin-14 Ncd motor alters both nucleotide and microtubule binding, although the mutated residue is not present in either site. Mutants show weak-ADP/tight-microtubule binding, instead of tight-ADP/weak-microtubule binding like wild type – they hydrolyze ATP faster than wild type, move faster in motility assays, and assemble long spindles with greatly elongated poles, which are also produced by simulations of assembly with tighter microtubule binding and faster sliding. The mutated residue acts like a mechanochemical coupling element – it transmits changes between the microtubule-binding and active sites, and can switch the state of the motor, increasing mechanical output by the motor. One possibility, based on our findings, is that movements by the residue and the loop that contains it could bend or distort the central β-sheet, mediating free energy changes that lead to force production.
Collapse
|
19
|
Wang W, Jiang Q, Argentini M, Cornu D, Gigant B, Knossow M, Wang C. Kif2C minimal functional domain has unusual nucleotide binding properties that are adapted to microtubule depolymerization. J Biol Chem 2012; 287:15143-53. [PMID: 22403406 DOI: 10.1074/jbc.m111.317859] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The kinesin-13 Kif2C hydrolyzes ATP and uses the energy released to disassemble microtubules. The mechanism by which this is achieved remains elusive. Here we show that Kif2C-(sN+M), a monomeric construct consisting of the motor domain with the proximal part of the N-terminal Neck extension but devoid of its more distal, unstructured, and highly basic part, has a robust depolymerase activity. When detached from microtubules, the Kif2C-(sN+M) nucleotide-binding site is occupied by ATP at physiological concentrations of adenine nucleotides. As a consequence, Kif2C-(sN+M) starts its interaction with microtubules in that state, which differentiates kinesin-13s from motile kinesins. Moreover, in this ATP-bound conformational state, Kif2C-(sN+M) has a higher affinity for soluble tubulin compared with microtubules. We propose a mechanism in which, in the first step, the specificity of ATP-bound Kif2C for soluble tubulin causes it to stabilize a curved conformation of tubulin heterodimers at the ends of microtubules. Data from an ATPase-deficient Kif2C mutant suggest that, then, ATP hydrolysis precedes and is required for tubulin release to take place. Finally, comparison with Kif2C-Motor indicates that the binding specificity for curved tubulin and, accordingly, the microtubule depolymerase activity are conferred to the motor domain by its N-terminal Neck extension.
Collapse
Affiliation(s)
- Weiyi Wang
- Institute of Protein Research, Tongji University, Shanghai 200092, China
| | | | | | | | | | | | | |
Collapse
|
20
|
Drummond DR. Regulation of microtubule dynamics by kinesins. Semin Cell Dev Biol 2011; 22:927-34. [PMID: 22001250 DOI: 10.1016/j.semcdb.2011.09.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 09/30/2011] [Indexed: 01/14/2023]
Abstract
The simple mechanistic and functional division of the kinesin family into either active translocators or non-motile microtubule depolymerases was initially appropriate but is now proving increasingly unhelpful, given evidence that several translocase kinesins can affect microtubule dynamics, whilst non-translocase kinesins can promote microtubule assembly and depolymerisation. Such multi-role kinesins act either directly on microtubule dynamics, by interaction with microtubules and tubulin, or indirectly, through the transport of other factors along the lattice to the microtubule tip. Here I review recent progress on the mechanisms and roles of these translocase kinesins.
Collapse
Affiliation(s)
- Douglas R Drummond
- Centre for Mechanochemical Cell Biology, Warwick Medical School, University of Warwick, Coventry, CV4 7AL, United Kingdom.
| |
Collapse
|
21
|
The kinesin-13 MCAK has an unconventional ATPase cycle adapted for microtubule depolymerization. EMBO J 2011; 30:3928-39. [PMID: 21873978 PMCID: PMC3209780 DOI: 10.1038/emboj.2011.290] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2011] [Accepted: 07/18/2011] [Indexed: 01/11/2023] Open
Abstract
Most kinesins move directionally along microtubules, but MCAK instead depolymerizes them. This study analyses the ATPase cycle of MCAK, identifying unusual kinetic features that fit with its unconventional activity. Unlike other kinesins, members of the kinesin-13 subfamily do not move directionally along microtubules but, instead, depolymerize them. To understand how kinesins with structurally similar motor domains can have such dissimilar functions, we elucidated the ATP turnover cycle of the kinesin-13, MCAK. In contrast to translocating kinesins, ATP cleavage, rather than product release, is the rate-limiting step for ATP turnover by MCAK; unpolymerized tubulin and microtubules accelerate this step. Further, microtubule ends fully activate the ATPase by accelerating the exchange of ADP for ATP. This tuning of the cycle adapts MCAK for its depolymerization activity: lattice-stimulated ATP cleavage drives MCAK into a weakly bound nucleotide state that reaches microtubule ends by diffusion, and end-specific acceleration of nucleotide exchange drives MCAK into a strongly bound state that promotes depolymerization. This altered cycle accounts well for the different mechanical behaviour of this kinesin, which depolymerizes microtubules from their ends, compared to translocating kinesins that walk along microtubules. Thus, the kinesin motor domain is a nucleotide-dependent engine that can be differentially tuned for transport or depolymerization functions.
Collapse
|
22
|
Affiliation(s)
- Sharyn A Endow
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
| | | | | |
Collapse
|
23
|
Wordeman L. How kinesin motor proteins drive mitotic spindle function: Lessons from molecular assays. Semin Cell Dev Biol 2010; 21:260-8. [PMID: 20109570 PMCID: PMC2844474 DOI: 10.1016/j.semcdb.2010.01.018] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Accepted: 01/19/2010] [Indexed: 12/31/2022]
Abstract
Kinesins are enzymes that use the energy of ATP to perform mechanical work. There are approximately 14 families of kinesins within the kinesin superfamily. Family classification is derived primarily from alignments of the sequences of the core motor domain. For this reason, the enzymatic behavior and motility of each motor generally reflects its family. At the cellular level, kinesin motors perform a variety of functions during cell division and within the mitotic spindle to ensure that chromosomes are segregated with the highest fidelity possible. The cellular functions of these motors are intimately related to their mechanical and enzymatic properties at the single molecule level. For this reason, motility studies designed to evaluate the activity of purified molecular motors are a requirement in order to understand, mechanistically, how these motors make the mitotic spindle work and what can cause the spindle to fail. This review will focus on a selection of illustrative kinesins, which have been studied at the molecular level in order to inform our understanding of their function in cells. In addition, the review will endeavor to point out some kinesins that have been studied extensively but which still lack sufficient molecular underpinnings to fully predict their contribution to spindle function.
Collapse
Affiliation(s)
- Linda Wordeman
- Department of Physiology & Biophysics, University of Washington School of Medicine, Seattle, WA 98195-7290, United States.
| |
Collapse
|
24
|
Kocik E, Skowronek KJ, Kasprzak AA. Interactions between subunits in heterodimeric Ncd molecules. J Biol Chem 2010; 284:35735-45. [PMID: 19858211 DOI: 10.1074/jbc.m109.024240] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The nonprocessive minus-end-directed kinesin-14 Ncd is involved in the organization of the microtubule (MT) network during mitosis. Only one of the two motor domains is involved in the interaction with the MT. The other head is tethered to the bound one. Here we prepared, purified, and characterized mutated Ncd molecules carrying point mutations in one of the heads, thus producing heterodimeric motors. The mutations tested included substitutions in Switch I and II: R552A, E585A, and E585D; the decoupling mutant N600K; and a deletion in the motor domain in one of the subunits resulting in a single-headed molecule (NcN). These proteins were isolated by two sequential affinity chromatography steps, followed by measurements of their affinities to MT, enzymatic properties, and the velocity of the microtubule gliding test in vitro. A striking observation is a low affinity of the single-headed NcN for MT both without nucleotides and in the presence of 5'-adenylyl-beta,gamma-imidodiphosphate, implying that the tethered head has a profound effect on the structure of the Ncd-MT complex. Mutated homodimers had no MT-activated ATPase and no motility, whereas NcN had motility comparable with that of the wild type Ncd. Although the heterodimers had one fully active and one inactive head, the ATPase and motility of Ncd heterodimers varied dramatically, clearly demonstrating that interactions between motor domains exist in Ncd. We also show that the bulk property of dimeric proteins that interact with the filament with only one of its heads depends also on the distribution of the filament-interacting subunits.
Collapse
Affiliation(s)
- Elzbieta Kocik
- Motor Proteins Laboratory, Department of Biochemistry, Nencki Institute of Experimental Biology, 3 Pasteur Street, 02-093 Warsaw
| | | | | |
Collapse
|
25
|
Abstract
Kinesin-8 family members function in microtubule length control and exhibit highly processive plus-end directed motility in conjunction with microtubule dissassembly activity. In a recent issue of Cell, Varga and colleagues describe how these two activities may be used to simultaneously measure and adjust the length of cellular microtubules.
Collapse
Affiliation(s)
- Linda Wordeman
- Department of Physiology and Biophysics. University of Washington School of Medicine. Seattle, WA 98195, USA.
| | | |
Collapse
|
26
|
Peris L, Wagenbach M, Lafanechère L, Brocard J, Moore AT, Kozielski F, Job D, Wordeman L, Andrieux A. Motor-dependent microtubule disassembly driven by tubulin tyrosination. ACTA ACUST UNITED AC 2009; 185:1159-66. [PMID: 19564401 PMCID: PMC2712961 DOI: 10.1083/jcb.200902142] [Citation(s) in RCA: 242] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
In cells, stable microtubules (MTs) are covalently modified by a carboxypeptidase, which removes the C-terminal Tyr residue of α-tubulin. The significance of this selective detyrosination of MTs is not understood. In this study, we report that tubulin detyrosination in fibroblasts inhibits MT disassembly. This inhibition is relieved by overexpression of the depolymerizing motor mitotic centromere-associated kinesin (MCAK). Conversely, suppression of MCAK expression prevents disassembly of normal tyrosinated MTs in fibroblasts. Detyrosination of MTs suppresses the activity of MCAK in vitro, apparently as the result of a decreased affinity of the adenosine diphosphate (ADP)–inorganic phosphate- and ADP-bound forms of MCAK for the MT lattice. Detyrosination also impairs MT disassembly in neurons and inhibits the activity of the neuronal depolymerizing motor KIF2A in vitro. These results indicate that MT depolymerizing motors are directly inhibited by the detyrosination of tubulin, resulting in the stabilization of cellular MTs. Detyrosination of transiently stabilized MTs may give rise to persistent subpopulations of disassembly-resistant polymers to sustain subcellular cytoskeletal differentiation.
Collapse
Affiliation(s)
- Leticia Peris
- Institut National de la Santé et de la Recherche Medicale Unité 836, Institut des Neurosciences de Grenoble, 38042 Grenoble, Cedex 9, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Mulder AM, Glavis-Bloom A, Moores CA, Wagenbach M, Carragher B, Wordeman L, Milligan RA. A new model for binding of kinesin 13 to curved microtubule protofilaments. ACTA ACUST UNITED AC 2009; 185:51-7. [PMID: 19332892 PMCID: PMC2700504 DOI: 10.1083/jcb.200812052] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Kinesin motor proteins use adenosine triphosphate hydrolysis to do work on microtubules (MTs). Most kinesins walk along the MT, but class 13 kinesins instead uniquely recognize MT ends and depolymerize MT protofilaments. We have used electron microscopy (EM) to understand the molecular interactions by which kinesin 13 performs these tasks. Although a construct of only the motor domain of kinesin 13 binds to every heterodimer of a tubulin ring, a construct containing the neck and the motor domain occupies alternate binding sites. Likewise, EM maps of the dimeric full-length (FL) protein exhibit alternate site binding but reveal density for only one of two motor heads. These results indicate that the second head of dimeric kinesin 13 does not have access to adjacent binding sites on the curved protofilament and suggest that the neck alone is sufficient to obstruct access. Additionally, the FL construct promotes increased stacking of rings compared with other constructs. Together, these data suggest a model for kinesin 13 depolymerization in which increased efficiency is achieved by binding of one kinesin 13 molecule to adjacent protofilaments.
Collapse
Affiliation(s)
- Anke M Mulder
- Department of Cell Biology, The Scripps Research Institute, La Jolla, CA 92037, USA
| | | | | | | | | | | | | |
Collapse
|