1
|
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.
Collapse
Affiliation(s)
- Marjatta Raudaskoski
- Molecular Plant Biology, Department of Life Technologies, University of Turku, 20014 Turku, Finland
| |
Collapse
|
2
|
Chaudhary AR, Lu H, Krementsova EB, Bookwalter CS, Trybus KM, Hendricks AG. MAP7 regulates organelle transport by recruiting kinesin-1 to microtubules. J Biol Chem 2019; 294:10160-10171. [PMID: 31085585 PMCID: PMC6664170 DOI: 10.1074/jbc.ra119.008052] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 05/07/2019] [Indexed: 12/14/2022] Open
Abstract
Microtubule-associated proteins (MAPs) regulate microtubule polymerization, dynamics, and organization. In addition, MAPs alter the motility of kinesin and dynein to control trafficking along microtubules. MAP7 (ensconsin, E-MAP-115) is a ubiquitous MAP that organizes the microtubule cytoskeleton in mitosis and neuronal branching. MAP7 also recruits kinesin-1 to microtubules. To understand how the activation of kinesin-1 by MAP7 regulates the motility of organelles transported by ensembles of kinesin and dynein, we isolated organelles and reconstituted their motility in vitro In the absence of MAP7, isolated phagosomes exhibit approximately equal fractions of plus- and minus-end-directed motility along microtubules. MAP7 causes a pronounced shift in motility; phagosomes move toward the plus-end ∼80% of the time, and kinesin teams generate more force. To dissect MAP7-mediated regulation of kinesin-driven transport, we examined its effects on the motility and force generation of single and teams of full-length kinesin-1 motors. We find that MAP7 does not alter the force exerted by a single kinesin-1 motor, but instead increases its binding rate to the microtubule. For ensembles of kinesin, a greater number of kinesin motors are simultaneously engaged and generating force to preferentially target organelles toward the microtubule plus-end.
Collapse
Affiliation(s)
- Abdullah R Chaudhary
- From the Department of Bioengineering, McGill University, Montréal, Quebec H3A 0C3, Canada and
| | - Hailong Lu
- the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405-0075
| | - Elena B Krementsova
- the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405-0075
| | - Carol S Bookwalter
- the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405-0075
| | - Kathleen M Trybus
- the Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, Vermont 05405-0075
| | - Adam G Hendricks
- From the Department of Bioengineering, McGill University, Montréal, Quebec H3A 0C3, Canada and
| |
Collapse
|
3
|
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.
Collapse
|
4
|
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.
Collapse
Affiliation(s)
- Kristen J Verhey
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan 48109-2200, USA.
| | | |
Collapse
|
5
|
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.
Collapse
Affiliation(s)
- Yao Liang Wong
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL 60611, USA
| | | | | | | | | |
Collapse
|
6
|
Structure of the complex of a mitotic kinesin with its calcium binding regulator. Proc Natl Acad Sci U S A 2009; 106:8175-9. [PMID: 19416847 DOI: 10.1073/pnas.0811131106] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Much of the transport, tension, and movement in mitosis depends on kinesins, the ATP-powered microtubule-based motors. We report the crystal structure of a kinesin complex, the mitotic kinesin KCBP bound to its principal regulator KIC. Shown to be a Ca(2+) sensor, KIC works as an allosteric trap. Extensive intermolecular interactions with KIC stabilize kinesin in its ADP-bound conformation. A critical component of the kinesin motile mechanism, called the neck mimic, switches its association from kinesin to KIC, stalling the motor. KIC denies access of the motor to its track by steric interference. Two major features of this regulation, allosteric trapping and steric blocking, are likely to be general for all kinesins.
Collapse
|
7
|
Abstract
The protein family of kinesins contains processive motor proteins that move stepwise along microtubules. This mechanism requires the precise coupling of the catalytic steps in the two heads, and their precise mechanical coordination. Here we show that these functionalities can be uncoupled in chimera of processive and non-processive kinesins. A chimera with the motor domain of Kinesin-1 and the dimerization domain of a non-processive Kinesin-3 motor behaves qualitatively as conventional kinesin and moves processively in TIRF and bead motility assays, suggesting that spatial proximity of two Kinein-1 motor domains is sufficient for processive behavior. In the reverse chimera, the non-processive motor domains are unable to step along microtubules, despite the presence of the Kinesin-1 neck coiled coil. Still, ATP-binding to one head of these chimera induces ADP-release from the partner head, a characteristic feature of alternating site catalysis. These results show that processive movement of kinesin dimers requires elements in the motor head that respond to ADP-release and induce stepping, in addition to a proper spacing of the motor heads via the neck coiled coil.
Collapse
|
8
|
The kinesin-1 motor protein is regulated by a direct interaction of its head and tail. Proc Natl Acad Sci U S A 2008; 105:8938-43. [PMID: 18579780 DOI: 10.1073/pnas.0803575105] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kinesin-1 is a molecular motor protein that transports cargo along microtubules. Inside cells, the vast majority of kinesin-1 is regulated to conserve ATP and to ensure its proper intracellular distribution and coordination with other molecular motors. Regulated kinesin-1 folds in half at a hinge in its coiled-coil stalk. Interactions between coiled-coil regions near the enzymatically active heads at the N terminus and the regulatory tails at the C terminus bring these globular elements in proximity and stabilize the folded conformation. However, it has remained a mystery how kinesin-1's microtubule-stimulated ATPase activity is regulated in this folded conformation. Here, we present evidence for a direct interaction between the kinesin-1 head and tail. We photochemically cross-linked heads and tails and produced an 8-A cryoEM reconstruction of the cross-linked head-tail complex on microtubules. These data demonstrate that a conserved essential regulatory element in the kinesin-1 tail interacts directly and specifically with the enzymatically critical Switch I region of the head. This interaction suggests a mechanism for tail-mediated regulation of the ATPase activity of kinesin-1. In our structure, the tail makes simultaneous contacts with the kinesin-1 head and the microtubule, suggesting the tail may both regulate kinesin-1 in solution and hold it in a paused state with high ADP affinity on microtubules. The interaction of the Switch I region of the kinesin-1 head with the tail is strikingly similar to the interactions of small GTPases with their regulators, indicating that other kinesin motors may share similar regulatory mechanisms.
Collapse
|
9
|
Röhlk C, Rohlfs M, Leier S, Schliwa M, Liu X, Parsch J, Woehlke G. Properties of the Kinesin-1 motor DdKif3 from Dictyostelium discoideum. Eur J Cell Biol 2007; 87:237-49. [PMID: 18160177 DOI: 10.1016/j.ejcb.2007.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2007] [Revised: 11/02/2007] [Accepted: 11/05/2007] [Indexed: 10/22/2022] Open
Abstract
The amoeba Dictyostelium discoideum possesses genes for 13 different kinesins. Here we characterize DdKif3, a member of the Kinesin-1 family. Kinesin-1 motors form homodimers that can move micrometer-long distances on microtubules using the energy derived from ATP hydrolysis. We expressed recombinant motors in Escherichia coli and tested them in different in vitro assays. Full-length and truncated Kif3 motors were active in gliding and ATPase assays. They showed a strong dependence on ionic strength. Like the full-length motor, the truncated DdKif3-592 motor (aa 1-592; comprising motor domain, neck, and partial stalk) reached its maximum speed of around 2.0micrcom s(-1) at a potassium acetate concentration of 200mM. The shortened DdKif3-342 motor (aa 1-342; comprising motor domain, partial neck) showed a high ATP turnover, comparable to that of the fungal Kinesin-1, Nkin. Results from the duty cycle calculations and gliding assays indicate that DdKif3 is a processive motor. A GFP-fusion protein revealed a mainly cytoplasmic localization of DdKif3. Immunofluorescence staining makes an association with the endoplasmic reticulum or mitochondria unlikely. Despite a similar phylogenetic distance to both metazoa and fungi, in terms of its biochemical properties DdKif3 revealed a closer similarity to fungal than animal kinesins.
Collapse
Affiliation(s)
- Christian Röhlk
- Department of Physics, Technical University Munich, James-Franck-Strasse, D-85748 Garching, Germany
| | | | | | | | | | | | | |
Collapse
|
10
|
Cappello G, Pierobon P, Symonds C, Busoni L, Christof J, Gebhardt M, Rief M, Prost J. Myosin V stepping mechanism. Proc Natl Acad Sci U S A 2007; 104:15328-33. [PMID: 17878301 PMCID: PMC2000544 DOI: 10.1073/pnas.0706653104] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We observe the myosin V stepping mechanism by traveling wave tracking. This technique, associated with optical tweezers, allows one to follow a scattering particle in a two-dimensional plane, with nanometer accuracy and a temporal resolution in the microsecond range. We have observed that, at the millisecond time scale, the myosin V combines longitudinal and vertical motions during the step. Because at this time scale the steps appear heterogeneous, we deduce their general features by aligning and averaging a large number of them. Our data show that the 36-nm step occurs in three main stages. First, the myosin center of mass moves forward 5 nm; the duration of this short prestep depends on the ATP concentration. Second, the motor performs a fast motion over 23 nm; this motion is associated to a vertical movement of the myosin center of mass, whose distance from the actin filament increases by 6 nm. Third, the myosin head freely diffuses toward the next binding site and the vertical position is recovered. We propose a simple model to describe the step mechanism of the dimeric myosin V.
Collapse
Affiliation(s)
- Giovanni Cappello
- *Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, 75231 Paris, France; and
- To whom correspondence may be addressed. E-mail: or
| | - Paolo Pierobon
- *Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, 75231 Paris, France; and
| | - Clémentine Symonds
- *Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, 75231 Paris, France; and
| | - Lorenzo Busoni
- *Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, 75231 Paris, France; and
| | | | - M. Gebhardt
- Physics Department E22, Technical University of Munich, James-Franck-Strasse, D-85748 Garching, Germany
| | - Matthias Rief
- Physics Department E22, Technical University of Munich, James-Franck-Strasse, D-85748 Garching, Germany
| | - Jacques Prost
- *Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, 75231 Paris, France; and
- To whom correspondence may be addressed. E-mail: or
| |
Collapse
|
11
|
Benniston AC, Harriman A, Howell SL, Sams CA, Zhi YG. Intramolecular Excimer Formation and Delayed Fluorescence in Sterically Constrained Pyrene Dimers. Chemistry 2007; 13:4665-74. [PMID: 17285654 DOI: 10.1002/chem.200601498] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The synthesis is described for a series of five molecular dyads comprising pyrene-based terminals covalently linked through a 1,3-disubstituted phenylene spacer. The extent of through-space communication between the pyrene units is modulated by steric interactions imposed by bulky moieties attached at the 6,8-positions of each pyrene unit. For the control compound, only hydrogen atoms occupy the 6,8 positions (DP1), whereas the remaining compounds incorporate ethynylene groups terminated with either triisopropylsilyl (DP2), 1-tert-butylbenzene (DP3), 2,6-di-tert-butylbenzene (DP4) or 1-tert-butyl-3,5-dimethylbenzene (DP5) units. Each compound shows a mixture of monomer and excimer fluorescence in fluid solution at room temperature, but only monomer emission in a glassy matrix at 77 K. The ratio of monomer to excimer fluorescence depends markedly on the molecular structure; DP1 is heavily biased in favour of the excimer and DP4 is enriched with monomer fluorescence. Photophysical properties, including laser induced and delayed fluorescence data, are reported for each compound. Delayed fluorescence occurs by both intramolecular and bimolecular steps, but these events take place on different timescales. The possibility is raised for using intramolecular triplet-triplet annihilation as a means of molecular imaging.
Collapse
Affiliation(s)
- Andrew C Benniston
- Molecular Photonics Laboratory, School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne, UK
| | | | | | | | | |
Collapse
|
12
|
Blasius TL, Cai D, Jih GT, Toret CP, Verhey KJ. Two binding partners cooperate to activate the molecular motor Kinesin-1. ACTA ACUST UNITED AC 2007; 176:11-7. [PMID: 17200414 PMCID: PMC2063617 DOI: 10.1083/jcb.200605099] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The regulation of molecular motors is an important cellular problem, as motility in the absence of cargo results in futile adenosine triphosphate hydrolysis. When not transporting cargo, the microtubule (MT)-based motor Kinesin-1 is kept inactive as a result of a folded conformation that allows autoinhibition of the N-terminal motor by the C-terminal tail. The simplest model of Kinesin-1 activation posits that cargo binding to nonmotor regions relieves autoinhibition. In this study, we show that binding of the c-Jun N-terminal kinase-interacting protein 1 (JIP1) cargo protein is not sufficient to activate Kinesin-1. Because two regions of the Kinesin-1 tail are required for autoinhibition, we searched for a second molecule that contributes to activation of the motor. We identified fasciculation and elongation protein zeta1 (FEZ1) as a binding partner of kinesin heavy chain. We show that binding of JIP1 and FEZ1 to Kinesin-1 is sufficient to activate the motor for MT binding and motility. These results provide the first demonstration of the activation of a MT-based motor by cellular binding partners.
Collapse
Affiliation(s)
- T Lynne Blasius
- Department of Cell Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | | | |
Collapse
|
13
|
Cai D, Hoppe AD, Swanson JA, Verhey KJ. Kinesin-1 structural organization and conformational changes revealed by FRET stoichiometry in live cells. J Cell Biol 2007; 176:51-63. [PMID: 17200416 PMCID: PMC2063625 DOI: 10.1083/jcb.200605097] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Accepted: 12/01/2006] [Indexed: 11/22/2022] Open
Abstract
Kinesin motor proteins drive the transport of cellular cargoes along microtubule tracks. How motor protein activity is controlled in cells is unresolved, but it is likely coupled to changes in protein conformation and cargo association. By applying the quantitative method fluorescence resonance energy transfer (FRET) stoichiometry to fluorescent protein (FP)-labeled kinesin heavy chain (KHC) and kinesin light chain (KLC) subunits in live cells, we studied the overall structural organization and conformation of Kinesin-1 in the active and inactive states. Inactive Kinesin-1 molecules are folded and autoinhibited such that the KHC tail blocks the initial interaction of the KHC motor with the microtubule. In addition, in the inactive state, the KHC motor domains are pushed apart by the KLC subunit. Thus, FRET stoichiometry reveals conformational changes of a protein complex in live cells. For Kinesin-1, activation requires a global conformational change that separates the KHC motor and tail domains and a local conformational change that moves the KHC motor domains closer together.
Collapse
Affiliation(s)
- Dawen Cai
- Biophysics Research Division, University of Michigan, Ann Arbor, MI 48109, USA
| | | | | | | |
Collapse
|
14
|
Ems-McClung SC, Hertzer KM, Zhang X, Miller MW, Walczak CE. The interplay of the N- and C-terminal domains of MCAK control microtubule depolymerization activity and spindle assembly. Mol Biol Cell 2007; 18:282-94. [PMID: 17093055 PMCID: PMC1751331 DOI: 10.1091/mbc.e06-08-0724] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2006] [Revised: 09/27/2006] [Accepted: 10/30/2006] [Indexed: 11/11/2022] Open
Abstract
Spindle assembly and accurate chromosome segregation require the proper regulation of microtubule dynamics. MCAK, a Kinesin-13, catalytically depolymerizes microtubules, regulates physiological microtubule dynamics, and is the major catastrophe factor in egg extracts. Purified GFP-tagged MCAK domain mutants were assayed to address how the different MCAK domains contribute to in vitro microtubule depolymerization activity and physiological spindle assembly activity in egg extracts. Our biochemical results demonstrate that both the neck and the C-terminal domain are necessary for robust in vitro microtubule depolymerization activity. In particular, the neck is essential for microtubule end binding, and the C-terminal domain is essential for tight microtubule binding in the presence of excess tubulin heterodimer. Our physiological results illustrate that the N-terminal domain is essential for regulating microtubule dynamics, stimulating spindle bipolarity, and kinetochore targeting; whereas the C-terminal domain is necessary for robust microtubule depolymerization activity, limiting spindle bipolarity, and enhancing kinetochore targeting. Unexpectedly, robust MCAK microtubule (MT) depolymerization activity is not needed for sperm-induced spindle assembly. However, high activity is necessary for proper physiological MT dynamics as assayed by Ran-induced aster assembly. We propose that MCAK activity is spatially controlled by an interplay between the N- and C-terminal domains during spindle assembly.
Collapse
Affiliation(s)
| | | | - Xin Zhang
- Department of Biology, Indiana University, Bloomington, IN 47405; and
| | - Mill W. Miller
- Department of Biological Sciences, Wright State University, Dayton, OH 45435
| | | |
Collapse
|
15
|
Imanishi M, Endres NF, Gennerich A, Vale RD. Autoinhibition regulates the motility of the C. elegans intraflagellar transport motor OSM-3. ACTA ACUST UNITED AC 2006; 174:931-7. [PMID: 17000874 PMCID: PMC2064385 DOI: 10.1083/jcb.200605179] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OSM-3 is a Kinesin-2 family member from Caenorhabditis elegans that is involved in intraflagellar transport (IFT), a process essential for the construction and maintenance of sensory cilia. In this study, using a single-molecule fluorescence assay, we show that bacterially expressed OSM-3 in solution does not move processively (multiple steps along a microtubule without dissociation) and displays low microtubule-stimulated adenosine triphosphatase (ATPase) activity. However, a point mutation (G444E) in a predicted hinge region of OSM-3's coiled-coil stalk as well as a deletion of that hinge activate ATPase activity and induce robust processive movement. These hinge mutations also cause a conformational change in OSM-3, causing it to adopt a more extended conformation. The motility of wild-type OSM-3 also can be activated by attaching the motor to beads in an optical trap, a situation that may mimic attachment to IFT cargo. Our results suggest that OSM-3 motility is repressed by an intramolecular interaction that involves folding about a central hinge and that IFT cargo binding relieves this autoinhibition in vivo. Interestingly, the G444E allele in C. elegans produces similar ciliary defects to an osm-3–null mutation, suggesting that autoinhibition is important for OSM-3's biological function.
Collapse
Affiliation(s)
- Miki Imanishi
- Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94107, USA
| | | | | | | |
Collapse
|
16
|
Kerssemakers J, Howard J, Hess H, Diez S. The distance that kinesin-1 holds its cargo from the microtubule surface measured by fluorescence interference contrast microscopy. Proc Natl Acad Sci U S A 2006; 103:15812-7. [PMID: 17035506 PMCID: PMC1595308 DOI: 10.1073/pnas.0510400103] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kinesin-1 is a motor protein that carries cellular cargo such as membrane-bounded organelles along microtubules (MTs). The homodimeric motor molecule contains two N-terminal motor domains (the motor "heads"), a long coiled-coil domain (the "rod" or "stalk"), and two small globular "tail" domains. Much has been learned about how kinesin's heads step along a MT and how the tail is involved in cargo binding and autoinhibition. However, little is known about the role of the rod. Here, we investigate the extension of the rod during active transport by measuring the height at which MTs glide over a kinesin-coated surface in the presence of ATP. To perform height measurements with nanometer precision, we used fluorescence interference contrast microscopy, which is based on the self-interference of fluorescent light from objects near a reflecting surface. Using an in situ calibrating method, we determined that kinesin-1 molecules elevate gliding MTs 17 +/- 2 nm (mean +/- SEM) above the surface. When varying the composition of the surrounding nucleotides or removing the negatively charged -COOH termini of the MTs by subtilisin digestion, we found no significant changes in the measured distance. Even though this distance is significantly shorter than the contour length of the motor molecule ( approximately 60 nm), it may be sufficient to prevent proteins bound to the MTs or prevent the organelles from interfering with transport.
Collapse
Affiliation(s)
- Jacob Kerssemakers
- *Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; and
| | - Jonathon Howard
- *Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; and
| | - Henry Hess
- Department of Materials Science and Engineering, University of Florida, 160 Rhines Hall, Gainesville, FL 32611
| | - Stefan Diez
- *Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany; and
- To whom correspondence should be addressed. E-mail:
| |
Collapse
|
17
|
Adio S, Bloemink M, Hartel M, Leier S, Geeves MA, Woehlke G. Kinetic and mechanistic basis of the nonprocessive Kinesin-3 motor NcKin3. J Biol Chem 2006; 281:37782-93. [PMID: 17012747 DOI: 10.1074/jbc.m605061200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kinesin-3 motors have been shown to transport cellular cargo along microtubules and to function according to mechanisms that differ from the conventional hand-over-hand mechanism. To find out whether the mechanisms described for Kif1A and CeUnc104 cover the full spectrum of Kinesin-3 motors, we characterize here NcKin3, a novel member of the Kinesin-3 family that localizes to mitochondria of ascomycetes. We show that NcKin3 does not move in a K-loop-dependent way as Kif1A or in a cluster-dependent way as CeUnc104. Its in vitro gliding velocity ranges between 0.30 and 0.64 mum/s and correlates positively with motor density. The processivity index (k(bi,ratio)) of approximately 3 reveals that not more than three ATP molecules are hydrolyzed per productive microtubule encounter. The NcKin3 duty ratio of 0.03 indicates that the motor spends only a minute fraction of the ATPase cycle attached to the filament. Unlike other Kinesin-3 family members, NcKin3 forms stable dimers, but only one subunit releases ADP in a microtubule-dependent fashion. Together, these data exclude a processive hand-over-hand mechanism of movement and suggest a power-stroke mechanism where nucleotide-dependent structural changes in a single motor domain lead to displacement of the motor along the filament. Thus, NcKin3 is the first plus end-directed kinesin motor that is dimeric but moves in a nonprocessive fashion to its destination.
Collapse
Affiliation(s)
- Sarah Adio
- Institute for Cell Biology, Ludwig-Maximilians-University Munich, Schillerstrasse 42, D-80336 Munich, Germany and Department of Biosciences, University of Kent, Canterbury CT2 7NJ, United Kingdom
| | | | | | | | | | | |
Collapse
|
18
|
Jaud J, Bathe F, Schliwa M, Rief M, Woehlke G. Flexibility of the neck domain enhances Kinesin-1 motility under load. Biophys J 2006; 91:1407-12. [PMID: 16714343 PMCID: PMC1518645 DOI: 10.1529/biophysj.105.076265] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Kinesin-1 is a dimeric motor protein that moves stepwise along microtubules. A two-stranded alpha-helical coiled-coil formed by the neck domain links the two heads of the molecule, and forces the motor heads to alternate. By exchanging the particularly soft neck region of the conventional kinesin from the fungus Neurospora crassa with an artificial, highly stable coiled-coil we investigated how this domain affects motor kinetics and motility. Under unloaded standard conditions, both motor constructs developed the same gliding velocity. However, in a force-feedback laser trap the mutant showed increasing motility defects with increasing loads, and did not reach wild-type velocities and run lengths. The stall force dropped significantly from 4.1 to 3.0 pN. These results indicate the compliance of kinesin's neck is important to sustain motility under load, and reveal a so far unknown constrain on the imperfect coiled-coil heptad pattern of Kinesin-1. We conclude that coiled-coil structures, a motif encountered in various types of molecular motors, are not merely a clamp for linking two heavy chains to a functional unit but may have specifically evolved to allow motor progression in a viscous, inhomogeneous environment or when several motors attached to a transported vesicle are required to cooperate efficiently.
Collapse
Affiliation(s)
- Johann Jaud
- Physics Department E22, Technical University Munich, Garching, Germany
| | | | | | | | | |
Collapse
|
19
|
Hahlen K, Ebbing B, Reinders J, Mergler J, Sickmann A, Woehlke G. Feedback of the kinesin-1 neck-linker position on the catalytic site. J Biol Chem 2006; 281:18868-77. [PMID: 16682419 DOI: 10.1074/jbc.m508019200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Kinesin-1 motor proteins step along microtubules by a mechanism in which the heads cycle through microtubule-bound and unbound states in an interlaced fashion. An important contribution to head-head coordination arises from the action of the neck-linker that docks onto the core motor domain upon ATP binding. We show here that the docked neck-linker not only guides the microtubule-unbound head to the next microtubule binding site but also signals its position to the head to which it is attached. Cross-linking studies on mutated kinesin constructs reveal that residues at the interface motor core/docked neck-linker, among them most importantly a conserved tyrosine, are involved in this feedback. The primary effect of the docked neck-linker is a reduced microtubule binding affinity in the ADP state.
Collapse
Affiliation(s)
- Katrin Hahlen
- Institute for Cell Biology, Ludwig-Maximilians University, Schillerstrasse 42, 80336 München, Germany
| | | | | | | | | | | |
Collapse
|
20
|
Lakämper S, Meyhöfer E. Back on track – On the role of the microtubule for kinesin motility and cellular function. J Muscle Res Cell Motil 2006; 27:161-71. [PMID: 16453157 DOI: 10.1007/s10974-005-9052-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2005] [Accepted: 12/08/2005] [Indexed: 10/25/2022]
Abstract
The evolution of cytoskeletal filaments (actin- and intermediate-filaments, and the microtubules) and their associated motor- and non-motor-proteins has enabled the eukaryotic cell to achieve complex organizational and structural tasks. This ability to control cellular transport processes and structures allowed for the development of such complex cellular organelles like cilia or flagella in single-cell organisms and made possible the development and differentiation of multi-cellular organisms with highly specialized, polarized cells. Also, the faithful segregation of large amounts of genetic information during cell division relies crucially on the reorganization and control of the cytoskeleton, making the cytoskeleton a key prerequisite for the development of highly complex genomes. Therefore, it is not surprising that the eukaryotic cell continuously invests considerable resources in the establishment, maintenance, modification and rearrangement of the cytoskeletal filaments and the regulation of its interaction with accessory proteins. Here we review the literature on the interaction between microtubules and motor-proteins of the kinesin-family. Our particular interest is the role of the microtubule in the regulation of kinesin motility and cellular function. After an introduction of the kinesin-microtubule interaction we focus on two interrelated aspects: (1) the active allosteric participation of the microtubule during the interaction with kinesins in general and (2) the possible regulatory role of post-translational modifications of the microtubule in the kinesin-microtubule interaction.
Collapse
Affiliation(s)
- Stefan Lakämper
- Physics of Complex Systems, Vrije Universiteit Amsterdam, De Boelelaan 1081, 1081 HV, Amsterdam, The Netherlands
| | | |
Collapse
|
21
|
Adio S, Reth J, Bathe F, Woehlke G. Review: regulation mechanisms of Kinesin-1. J Muscle Res Cell Motil 2006; 27:153-60. [PMID: 16450053 DOI: 10.1007/s10974-005-9054-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2005] [Accepted: 12/08/2005] [Indexed: 01/16/2023]
Abstract
Kinesin-1 microtubule motors are common kinesin motors from protozoa, fungi and animals. They transport vesicular or particle cargo in a strictly regulated manner. The relatively well-studied tail inhibition mechanism is based on a conformational change that leads to an interaction of Kinesin-1's tail with the junction of neck and hinge regions. This folding causes a decrease in microtubule binding and motor activity. In fungal Kinesin-1 motors several lines of evidence suggest that a conserved tyrosine in the neck coiled-coil mediates this inhibition. In the active state, a region surrounding a conserved tryptophan in the hinge stabilises the neck coiled-coil, and prevents the tyrosine from inhibiting. Although animal and fungal Kinesin-1 motors are clearly homologous and function according to the same chemo-mechanical mechanism, they differ in their regulation. Unlike fungal Kinesin-1s, animal kinesins associate with light chains that are important for regulation and cargo interaction. Several proteins interacting with animal Kinesin-1 heavy or light chains are known, among them typical scaffolding proteins that seem to link Kinesin-1 to signalling pathways.
Collapse
Affiliation(s)
- Sarah Adio
- Institute for Cell Biology, University of Munich, Schillerstr. 42, D-80336, Munich, Germany
| | | | | | | |
Collapse
|
22
|
Marx A, Müller J, Mandelkow EM, Hoenger A, Mandelkow E. Interaction of kinesin motors, microtubules, and MAPs. J Muscle Res Cell Motil 2005; 27:125-37. [PMID: 16362723 DOI: 10.1007/s10974-005-9051-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2005] [Accepted: 11/18/2005] [Indexed: 11/30/2022]
Abstract
Kinesins are a family of microtubule-dependent motor proteins that carry cargoes such as vesicles, organelles, or protein complexes along microtubules. Here we summarize structural studies of the "conventional" motor protein kinesin-1 and its interactions with microtubules, as determined by X-ray crystallography and cryo-electron microscopy. In particular, we consider the docking between the kinesin motor domain and tubulin subunits and summarize the evidence that kinesin binds mainly to beta tubulin with the switch-2 helix close to the intradimer interface between alpha and beta tubulin.
Collapse
Affiliation(s)
- A Marx
- Max-Planck-Unit for Structural Molecular Biology, Notkestrasse 85, 22607, Hamburg, Germany
| | | | | | | | | |
Collapse
|