1
|
Muir KW, Batters C, Dendooven T, Yang J, Zhang Z, Burt A, Barford D. Structural mechanism of outer kinetochore Dam1-Ndc80 complex assembly on microtubules. Science 2023; 382:1184-1190. [PMID: 38060647 PMCID: PMC7615550 DOI: 10.1126/science.adj8736] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 10/25/2023] [Indexed: 12/18/2023]
Abstract
Kinetochores couple chromosomes to the mitotic spindle to segregate the genome during cell division. An error correction mechanism drives the turnover of kinetochore-microtubule attachments until biorientation is achieved. The structural basis for how kinetochore-mediated chromosome segregation is accomplished and regulated remains an outstanding question. In this work, we describe the cryo-electron microscopy structure of the budding yeast outer kinetochore Ndc80 and Dam1 ring complexes assembled onto microtubules. Complex assembly occurs through multiple interfaces, and a staple within Dam1 aids ring assembly. Perturbation of key interfaces suppresses yeast viability. Force-rupture assays indicated that this is a consequence of impaired kinetochore-microtubule attachment. The presence of error correction phosphorylation sites at Ndc80-Dam1 ring complex interfaces and the Dam1 staple explains how kinetochore-microtubule attachments are destabilized and reset.
Collapse
Affiliation(s)
- Kyle W. Muir
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Christopher Batters
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Tom Dendooven
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Jing Yang
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Ziguo Zhang
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - Alister Burt
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| | - David Barford
- MRC Laboratory of Molecular Biology; Francis Crick Avenue, Cambridge, CB2 0QH, UK
| |
Collapse
|
2
|
Sankaranarayanan SR, Polisetty SD, Das K, Dumbrepatil A, Medina-Pritchard B, Singleton M, Jeyaprakash AA, Sanyal K. Functional plasticity in chromosome-microtubule coupling on the evolutionary time scale. Life Sci Alliance 2023; 6:e202201720. [PMID: 37793775 PMCID: PMC10551642 DOI: 10.26508/lsa.202201720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 09/15/2023] [Accepted: 09/19/2023] [Indexed: 10/06/2023] Open
Abstract
The Dam1 complex is essential for mitotic progression across evolutionarily divergent fungi. Upon analyzing amino acid (aa) sequences of Dad2, a Dam1 complex subunit, we identified a conserved 10-aa-long Dad2 signature sequence (DSS). An arginine residue (R126) in the DSS is essential for viability in Saccharomyces cerevisiae that possesses point centromeres. The corresponding arginine residues are functionally important but not essential for viability in Candida albicans and Cryptococcus neoformans; both carry several kilobases long regional centromeres. The purified recombinant Dam1 complex containing either Dad2ΔDSS or Dad2R126A failed to bind microtubules (MTs) or form any visible rings like the WT complex. Intriguingly, functional analysis revealed that the requirement of the conserved arginine residue for chromosome biorientation and mitotic progression reduced with increasing centromere length. We propose that plasticity of the invariant arginine of Dad2 in organisms with regional centromeres is achieved by conditional elevation of the kinetochore protein(s) to enable multiple kinetochore MTs to bind to each chromosome. The capacity of a chromosome to bind multiple kinetochore MTs may mask the deleterious effects of such lethal mutations.
Collapse
Affiliation(s)
- Sundar Ram Sankaranarayanan
- https://ror.org/0538gdx71 Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Satya Dev Polisetty
- https://ror.org/0538gdx71 Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Kuladeep Das
- https://ror.org/0538gdx71 Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Arti Dumbrepatil
- https://ror.org/0538gdx71 Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| | - Bethan Medina-Pritchard
- https://ror.org/01nrxwf90 Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Martin Singleton
- https://ror.org/01nrxwf90 Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - A Arockia Jeyaprakash
- https://ror.org/01nrxwf90 Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
- Gene Center and Department of Biochemistry, Ludwig-Maximilian-Universität, Munich, Germany
| | - Kaustuv Sanyal
- https://ror.org/0538gdx71 Molecular Mycology Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru, India
| |
Collapse
|
3
|
Haase MAB, Ólafsson G, Flores RL, Boakye‐Ansah E, Zelter A, Dickinson MS, Lazar‐Stefanita L, Truong DM, Asbury CL, Davis TN, Boeke JD. DASH/Dam1 complex mutants stabilize ploidy in histone-humanized yeast by weakening kinetochore-microtubule attachments. EMBO J 2023; 42:e112600. [PMID: 36651597 PMCID: PMC10106983 DOI: 10.15252/embj.2022112600] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/16/2022] [Accepted: 12/20/2022] [Indexed: 01/19/2023] Open
Abstract
Forcing budding yeast to chromatinize their DNA with human histones manifests an abrupt fitness cost. We previously proposed chromosomal aneuploidy and missense mutations as two potential modes of adaptation to histone humanization. Here, we show that aneuploidy in histone-humanized yeasts is specific to a subset of chromosomes that are defined by their centromeric evolutionary origins but that these aneuploidies are not adaptive. Instead, we find that a set of missense mutations in outer kinetochore proteins drives adaptation to human histones. Furthermore, we characterize the molecular mechanism underlying adaptation in two mutants of the outer kinetochore DASH/Dam1 complex, which reduce aneuploidy by suppression of chromosome instability. Molecular modeling and biochemical experiments show that these two mutants likely disrupt a conserved oligomerization interface thereby weakening microtubule attachments. We propose a model through which weakened microtubule attachments promote increased kinetochore-microtubule turnover and thus suppress chromosome instability. In sum, our data show how a set of point mutations evolved in histone-humanized yeasts to counterbalance human histone-induced chromosomal instability through weakening microtubule interactions, eventually promoting a return to euploidy.
Collapse
Affiliation(s)
- Max A B Haase
- Institute for Systems Genetics and Department of Biochemistry and Molecular PharmacologyNYU Langone HealthNew YorkNYUSA
- Vilcek Institute of Graduate Biomedical SciencesNYU School of MedicineNew YorkNYUSA
| | - Guðjón Ólafsson
- Institute for Systems Genetics and Department of Biochemistry and Molecular PharmacologyNYU Langone HealthNew YorkNYUSA
| | - Rachel L Flores
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | | | - Alex Zelter
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | | | - Luciana Lazar‐Stefanita
- Institute for Systems Genetics and Department of Biochemistry and Molecular PharmacologyNYU Langone HealthNew YorkNYUSA
| | - David M Truong
- Department of Biomedical EngineeringNYU Tandon School of EngineeringBrooklynNYUSA
- Department of PathologyNYU Langone HealthNew YorkNYUSA
| | - Charles L Asbury
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
- Department of Physiology and BiophysicsUniversity of WashingtonSeattleWAUSA
| | - Trisha N Davis
- Department of BiochemistryUniversity of WashingtonSeattleWAUSA
| | - Jef D Boeke
- Institute for Systems Genetics and Department of Biochemistry and Molecular PharmacologyNYU Langone HealthNew YorkNYUSA
- Department of Biomedical EngineeringNYU Tandon School of EngineeringBrooklynNYUSA
- Department of Biochemistry and Molecular PharmacologyNYU Langone HealthNew YorkNYUSA
| |
Collapse
|
4
|
Zahm JA, Jenni S, Harrison SC. Structure of the Ndc80 complex and its interactions at the yeast kinetochore-microtubule interface. Open Biol 2023; 13:220378. [PMID: 36883282 PMCID: PMC9993044 DOI: 10.1098/rsob.220378] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
The conserved Ndc80 kinetochore complex, Ndc80c, is the principal link between mitotic spindle microtubules and centromere-associated proteins. We used AlphaFold 2 (AF2) to obtain predictions of the Ndc80 'loop' structure and of the Ndc80 : Nuf2 globular head domains that interact with the Dam1 subunit of the heterodecameric DASH/Dam1 complex (Dam1c). The predictions guided design of crystallizable constructs, with structures close to the predicted ones. The Ndc80 'loop' is a stiff, α-helical 'switchback' structure; AF2 predictions and positions of preferential cleavage sites indicate that flexibility within the long Ndc80c rod occurs instead at a hinge closer to the globular head. Conserved stretches of the Dam1 C terminus bind Ndc80c such that phosphorylation of Dam1 serine residues 257, 265 and 292 by the mitotic kinase Ipl1/Aurora B can release this contact during error correction of mis-attached kinetochores. We integrate the structural results presented here into our current molecular model of the kinetochore-microtubule interface. The model illustrates how multiple interactions between Ndc80c, DASH/Dam1c and the microtubule lattice stabilize kinetochore attachments.
Collapse
Affiliation(s)
- Jacob A. Zahm
- Department of Biological Chemistry and Molecular Pharmacology, and
| | - Simon Jenni
- Department of Biological Chemistry and Molecular Pharmacology, and
| | - Stephen C. Harrison
- Department of Biological Chemistry and Molecular Pharmacology, and
- Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115, USA
| |
Collapse
|
5
|
Bunning AR, Gupta Jr. ML. The importance of microtubule-dependent tension in accurate chromosome segregation. Front Cell Dev Biol 2023; 11:1096333. [PMID: 36755973 PMCID: PMC9899852 DOI: 10.3389/fcell.2023.1096333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2022] [Accepted: 01/11/2023] [Indexed: 01/24/2023] Open
Abstract
Accurate chromosome segregation is vital for cell and organismal viability. The mitotic spindle, a bipolar macromolecular machine composed largely of dynamic microtubules, is responsible for chromosome segregation during each cell replication cycle. Prior to anaphase, a bipolar metaphase spindle must be formed in which each pair of chromatids is attached to microtubules from opposite spindle poles. In this bipolar configuration pulling forces from the dynamic microtubules can generate tension across the sister kinetochores. The tension status acts as a signal that can destabilize aberrant kinetochore-microtubule attachments and reinforces correct, bipolar connections. Historically it has been challenging to isolate the specific role of tension in mitotic processes due to the interdependency of attachment and tension status at kinetochores. Recent technical and experimental advances have revealed new insights into how tension functions during mitosis. Here we summarize the evidence that tension serves as a biophysical signal that unifies multiple aspects of kinetochore and centromere function to ensure accurate chromosome segregation.
Collapse
|
6
|
Murray LE, Kim H, Rice LM, Asbury CL. Working strokes produced by curling protofilaments at disassembling microtubule tips can be biochemically tuned and vary with species. eLife 2022; 11:e83225. [PMID: 36580070 PMCID: PMC9799970 DOI: 10.7554/elife.83225] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Accepted: 11/25/2022] [Indexed: 12/30/2022] Open
Abstract
The disassembly of microtubules can generate force and drive intracellular motility. During mitosis, for example, chromosomes remain persistently attached via kinetochores to the tips of disassembling microtubules, which pull the sister chromatids apart. According to the conformational wave hypothesis, such force generation requires that protofilaments curl outward from the disassembling tips to exert pulling force directly on kinetochores. Rigorously testing this idea will require modifying the mechanical and energetic properties of curling protofilaments, but no way to do so has yet been described. Here, by direct measurement of working strokes generated in vitro by curling protofilaments, we show that their mechanical energy output can be increased by adding magnesium, and that yeast microtubules generate larger and more energetic working strokes than bovine microtubules. Both the magnesium and species-dependent increases in work output can be explained by lengthening the protofilament curls, without any change in their bending stiffness or intrinsic curvature. These observations demonstrate how work output from curling protofilaments can be tuned and suggest evolutionary conservation of the amount of curvature strain energy stored in the microtubule lattice.
Collapse
Affiliation(s)
- Lucas E Murray
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Haein Kim
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
| | - Luke M Rice
- Department of Biophysics, UT Southwestern Medical CenterDallasUnited States
- Department of Biochemistry, UT Southwestern Medical CenterDallasUnited States
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of WashingtonSeattleUnited States
- Department of Biochemistry, University of WashingtonSeattleUnited States
| |
Collapse
|
7
|
Flores RL, Peterson ZE, Zelter A, Riffle M, Asbury CL, Davis TN. Three interacting regions of the Ndc80 and Dam1 complexes support microtubule tip-coupling under load. J Cell Biol 2022; 221:213102. [PMID: 35353161 DOI: 10.1083/jcb.202107016] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/20/2021] [Accepted: 03/07/2022] [Indexed: 01/15/2023] Open
Abstract
Accurate mitosis requires kinetochores to make persistent, load-bearing attachments to dynamic microtubule tips, thereby coupling chromosome movements to tip growth and shortening. This tip-coupling behavior depends on the conserved Ndc80 complex and, in budding yeast, on the Dam1 complex, which bind each other directly via three distinct interacting regions. The functional relevance of these multiple interactions was mysterious. Here we show that interactions between two of these regions support the high rupture strengths that occur when applied force is rapidly increased and also support the stability of tip-coupling when force is held constant over longer durations. The contribution of either of these two regions to tip-coupling is reduced by phosphorylation by Aurora B kinase. The third interaction region makes no apparent contribution to rupture strength, but its phosphorylation by Aurora B kinase specifically decreases the long-term stability of tip-coupling. The specific reduction of long-term stability relative to short-term strength might have important implications for mitotic error correction.
Collapse
Affiliation(s)
- Rachel L Flores
- Department of Biochemistry, University of Washington, Seattle, WA
| | | | - Alex Zelter
- Department of Biochemistry, University of Washington, Seattle, WA
| | - Michael Riffle
- Department of Biochemistry, University of Washington, Seattle, WA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, WA
| |
Collapse
|
8
|
Meyer RE, Tipton AR, LaVictoire R, Gorbsky GJ, Dawson DS. Mps1 promotes poleward chromosome movements in meiotic prometaphase. Mol Biol Cell 2021; 32:1020-1032. [PMID: 33788584 PMCID: PMC8101486 DOI: 10.1091/mbc.e20-08-0525-t] [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] [Indexed: 11/25/2022] Open
Abstract
In prophase of meiosis I, homologous chromosomes pair and become connected by cross-overs. Chiasmata, the connections formed by cross-overs, enable the chromosome pair, called a bivalent, to attach as a single unit to the spindle. When the meiotic spindle forms in prometaphase, most bivalents are associated with one spindle pole and then go through a series of oscillations on the spindle, attaching to and detaching from microtubules until the partners of the bivalent become bioriented—attached to microtubules from opposite sides of the spindle. The conserved kinase, Mps1, is essential for the bivalents to be pulled by microtubules across the spindle in prometaphase. Here we show that MPS1 is needed for efficient triggering of the migration of microtubule-attached kinetochores toward the poles and promotes microtubule depolymerization. Our data support the model Mps1 acts at the kinetochore to coordinate the successful attachment of a microtubule and the triggering of microtubule depolymerization to then move the chromosome.
Collapse
Affiliation(s)
- Régis E Meyer
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Aaron R Tipton
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Rebecca LaVictoire
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104
| | - Gary J Gorbsky
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Dean S Dawson
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104.,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| |
Collapse
|
9
|
Chang CC, Hsia KC. More than a zip code: global modulation of cellular function by nuclear localization signals. FEBS J 2020; 288:5569-5585. [PMID: 33296547 DOI: 10.1111/febs.15659] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/03/2020] [Accepted: 12/07/2020] [Indexed: 12/27/2022]
Abstract
Extensive structural and functional studies have been carried out in the field of nucleocytoplasmic transport. Nuclear transport factors, such as Importin-α/-β, recognize nuclear localization signals (NLSs) on cargo, and together with the small GTPase Ran, facilitate their nuclear localization. However, it is now emerging that binding of nuclear transport factors to NLSs not only mediates nuclear transport but also contributes to a variety of cellular functions in eukaryotes. Here, we describe recent advances that reveal how NLSs facilitate diverse cellular functions beyond nuclear transport activity. We review separately NLS-mediated regulatory mechanisms at different levels of biological organization, including (a) assembly of higher-order structures; (b) cellular organelle dynamics; and (c) modulation of cellular stress responses and viral infections. Finally, we provide mechanistic insights into how NLSs can regulate such a broad range of functions via their structural and biochemical properties.
Collapse
Affiliation(s)
- Chih-Chia Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| | - Kuo-Chiang Hsia
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan.,Institute of Biochemistry and Molecular Biology, College of Life Sciences, National Yang-Ming University, Taipei, Taiwan
| |
Collapse
|
10
|
Abstract
The kinetochore is a complex structure whose function is absolutely essential. Unlike the centromere, the kinetochore at first appeared remarkably well conserved from yeast to humans, especially the microtubule-binding outer kinetochore. However, recent efforts towards biochemical reconstitution of diverse kinetochores challenge the notion of a similarly conserved architecture for the constitutively centromere-associated network of the inner kinetochore. This review briefly summarizes the evidence from comparative genomics for interspecific variability in inner kinetochore composition and focuses on novel biochemical evidence indicating that even homologous inner kinetochore protein complexes are put to different uses in different organisms.
Collapse
Affiliation(s)
- G E Hamilton
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| | - T N Davis
- Department of Biochemistry, University of Washington, Seattle, WA, USA
| |
Collapse
|
11
|
Gutierrez A, Kim JO, Umbreit NT, Asbury CL, Davis TN, Miller MP, Biggins S. Cdk1 Phosphorylation of the Dam1 Complex Strengthens Kinetochore-Microtubule Attachments. Curr Biol 2020; 30:4491-4499.e5. [PMID: 32946748 PMCID: PMC7497780 DOI: 10.1016/j.cub.2020.08.054] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 07/20/2020] [Accepted: 08/14/2020] [Indexed: 12/01/2022]
Abstract
To ensure the faithful inheritance of DNA, a macromolecular protein complex called the kinetochore sustains the connection between chromosomes and force-generating dynamic microtubules during cell division. Defects in this process lead to aneuploidy, a common feature of cancer cells and the cause of many developmental diseases [1, 2, 3, 4]. One of the major microtubule-binding activities in the kinetochore is mediated by the conserved Ndc80 complex (Ndc80c) [5, 6, 7]. In budding yeast, the retention of kinetochores on dynamic microtubule tips also depends on the essential heterodecameric Dam1 complex (Dam1c) [8, 9, 10, 11, 12, 13, 14, 15], which binds to the Ndc80c and is proposed to be a functional ortholog of the metazoan Ska complex [16, 17]. The load-bearing activity of the Dam1c depends on its ability to oligomerize, and the purified complex spontaneously self-assembles into microtubule-encircling oligomeric rings, which are proposed to function as collars that allow kinetochores to processively track the plus-end tips of microtubules and harness the forces generated by disassembling microtubules [10, 11, 12, 13, 14, 15, 18, 19, 20, 21, 22]. However, it is unknown whether there are specific regulatory events that promote Dam1c oligomerization to ensure accurate segregation. Here, we used a reconstitution system to discover that Cdk1, the major mitotic kinase that drives the cell cycle, phosphorylates the Ask1 component of the Dam1c to increase its residence time on microtubules and enhance kinetochore-microtubule attachment strength. We propose that Cdk1 activity promotes Dam1c oligomerization to ensure that kinetochore-microtubule attachments are stabilized as kinetochores come under tension in mitosis. Cdk1 phosphorylation of Dam1c strengthens kinetochore-microtubule attachments Ask1 is the key Cdk1 target in Dam1c that enhances for kinetochore-microtubule attachments Dynamic phosphorylation of Dam1c by Cdk1 is important in vivo Cdk1 phosphorylation of Ask1 appears to promote Dam1c oligomerization
Collapse
Affiliation(s)
- Abraham Gutierrez
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, Seattle, WA 98109, USA; Molecular and Cellular Biology Program, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Jae Ook Kim
- Department of Biochemistry, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Neil T Umbreit
- Department of Biochemistry, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, 1959 NE Pacific Street, Seattle, WA 98195, USA
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, 1705 NE Pacific Street, Seattle, WA 98195, USA
| | - Matthew P Miller
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, Seattle, WA 98109, USA
| | - Sue Biggins
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue N, Seattle, WA 98109, USA.
| |
Collapse
|
12
|
Microtubules pull the strings: disordered sequences as efficient couplers of microtubule-generated force. Essays Biochem 2020; 64:371-382. [PMID: 32502246 DOI: 10.1042/ebc20190078] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 05/01/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022]
Abstract
Microtubules are dynamic polymers that grow and shrink through addition or loss of tubulin subunits at their ends. Microtubule ends generate mechanical force that moves chromosomes and cellular organelles, and provides mechanical tension. Recent literature describes a number of proteins and protein complexes that couple dynamics of microtubule ends to movements of their cellular cargoes. These 'couplers' are quite diverse in their microtubule-binding domains (MTBDs), while sharing similarity in function, but a systematic understanding of the principles underlying their activity is missing. Here, I review various types of microtubule couplers, focusing on their essential activities: ability to follow microtubule ends and capture microtubule-generated force. Most of the couplers require presence of unstructured positively charged sequences and multivalency in their microtubule-binding sites to efficiently convert the microtubule-generated force into useful connection to a cargo. An overview of the microtubule features supporting end-tracking and force-coupling, and the experimental methods to assess force-coupling properties is also provided.
Collapse
|
13
|
Structural view of the yeast Dam1 complex, a ring-shaped molecular coupler for the dynamic microtubule end. Essays Biochem 2020; 64:359-370. [PMID: 32579171 DOI: 10.1042/ebc20190079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/25/2020] [Accepted: 05/27/2020] [Indexed: 11/17/2022]
Abstract
In a dividing eukaryotic cell, proper chromosome segregation requires the dynamic yet persistent attachment of kinetochores to spindle microtubules. In the budding yeast Saccharomyces cerevisiae, this function is especially crucial because each kinetochore is attached to a single microtubule; consequently, loss of attachment could lead to unrecoverable chromosome loss. The highly specialized heterodecameric Dam1 protein complex achieves this coupling by assembling into a microtubule-encircling ring that glides near the end of the dynamic microtubule to mediate chromosome motion. In recent years, we have learned a great deal about the structural properties of the Dam1 heterodecamer, its mechanism of self-assembly into rings, and its tethering to the kinetochore by the elongated Ndc80 complex. The most remarkable progress has resulted from defining the fine structures of helical bundles within Dam1 heterodecamer. In this review, we critically analyze structural observations collected by diverse approaches with the goal of obtaining a unified view of Dam1 ring architecture. A considerable consistency between different studies supports a coherent model of the circular core of the Dam1 ring. However, there are persistent uncertainties about the composition of ring protrusions and flexible extensions, as well as their roles in mediating ring core assembly and interactions with the Ndc80 complex and microtubule.
Collapse
|
14
|
Ustinov NB, Korshunova AV, Gudimchuk NB. Protein Complex NDC80: Properties, Functions, and Possible Role in Pathophysiology of Cell Division. BIOCHEMISTRY (MOSCOW) 2020; 85:448-462. [PMID: 32569552 DOI: 10.1134/s0006297920040057] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Mitotic division maintains genetic identity of any multicellular organism throughout an entire lifetime. Each time a parent cell divides, chromosomes are equally distributed between the daughter cells due to the action of mitotic spindle. Mitotic spindle is formed by the microtubules that represent dynamic polymers of tubulin protein. Spindle microtubules are attached end-on to kinetochores - large multi-protein complexes on chromosomes. This review focuses on the four-subunit NDC80 complex, one of the most important kinetochore elements that plays a major role in the attachment of assembling/disassembling microtubule ends to the chromosomes. Here, we summarize published data on the structure, properties, and regulation of the NDC80 complex and discuss possible relationship between changes in the expression of genes coding for the NDC80 complex components, mitotic disorders, and oncogenesis with special emphasis on the diagnostic and therapeutic potential of NDC80.
Collapse
Affiliation(s)
- N B Ustinov
- Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow, 119991, Russia
| | - A V Korshunova
- Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow, 119991, Russia.,Lomonosov Moscow State University, Faculty of Physics, Moscow, 119991, Russia
| | - N B Gudimchuk
- Center for Theoretical Problems of Physico-Chemical Pharmacology, Russian Academy of Sciences, Moscow, 119991, Russia. .,Lomonosov Moscow State University, Faculty of Physics, Moscow, 119991, Russia
| |
Collapse
|
15
|
Hamilton GE, Helgeson LA, Noland CL, Asbury CL, Dimitrova YN, Davis TN. Reconstitution reveals two paths of force transmission through the kinetochore. eLife 2020; 9:56582. [PMID: 32406818 PMCID: PMC7367685 DOI: 10.7554/elife.56582] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Accepted: 05/13/2020] [Indexed: 01/23/2023] Open
Abstract
Partitioning duplicated chromosomes equally between daughter cells is a microtubule-mediated process essential to eukaryotic life. A multi-protein machine, the kinetochore, drives chromosome segregation by coupling the chromosomes to dynamic microtubule tips, even as the tips grow and shrink through the gain and loss of subunits. The kinetochore must harness, transmit, and sense mitotic forces, as a lack of tension signals incorrect chromosome-microtubule attachment and precipitates error correction mechanisms. But though the field has arrived at a ‘parts list’ of dozens of kinetochore proteins organized into subcomplexes, the path of force transmission through these components has remained unclear. Here we report reconstitution of functional Saccharomyces cerevisiae kinetochore assemblies from recombinantly expressed proteins. The reconstituted kinetochores are capable of self-assembling in vitro, coupling centromeric nucleosomes to dynamic microtubules, and withstanding mitotically relevant forces. They reveal two distinct pathways of force transmission and Ndc80c recruitment.
Collapse
Affiliation(s)
- Grace E Hamilton
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Luke A Helgeson
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Cameron L Noland
- Department of Structural Biology, Genentech Inc, South San Francisco, United States
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Yoana N Dimitrova
- Department of Structural Biology, Genentech Inc, South San Francisco, United States
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, United States
| |
Collapse
|
16
|
Conti D, Gul P, Islam A, Martín-Durán JM, Pickersgill RW, Draviam VM. Kinetochores attached to microtubule-ends are stabilised by Astrin bound PP1 to ensure proper chromosome segregation. eLife 2019; 8:49325. [PMID: 31808746 PMCID: PMC6930079 DOI: 10.7554/elife.49325] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 12/01/2019] [Indexed: 12/12/2022] Open
Abstract
Microtubules segregate chromosomes by attaching to macromolecular kinetochores. Only microtubule-end attached kinetochores can be pulled apart; how these end-on attachments are selectively recognised and stabilised is not known. Using the kinetochore and microtubule-associated protein, Astrin, as a molecular probe, we show that end-on attachments are rapidly stabilised by spatially-restricted delivery of PP1 near the C-terminus of Ndc80, a core kinetochore-microtubule linker. PP1 is delivered by the evolutionarily conserved tail of Astrin and this promotes Astrin’s own enrichment creating a highly-responsive positive feedback, independent of biorientation. Abrogating Astrin:PP1-delivery disrupts attachment stability, which is not rescued by inhibiting Aurora-B, an attachment destabiliser, but is reversed by artificially tethering PP1 near the C-terminus of Ndc80. Constitutive Astrin:PP1-delivery disrupts chromosome congression and segregation, revealing a dynamic mechanism for stabilising attachments. Thus, Astrin-PP1 mediates a dynamic ‘lock’ that selectively and rapidly stabilises end-on attachments, independent of biorientation, and ensures proper chromosome segregation.
Collapse
Affiliation(s)
- Duccio Conti
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.,Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Parveen Gul
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Asifa Islam
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - José M Martín-Durán
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Richard W Pickersgill
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom
| | - Viji M Draviam
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.,Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
17
|
Ma G, Hu C, Li S, Gao X, Li H, Hu X. Simultaneous, hybrid single-molecule method by optical tweezers and fluorescence. NANOTECHNOLOGY AND PRECISION ENGINEERING 2019. [DOI: 10.1016/j.npe.2019.11.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
18
|
Hamilton G, Dimitrova Y, Davis TN. Seeing is believing: our evolving view of kinetochore structure, composition, and assembly. Curr Opin Cell Biol 2019; 60:44-52. [PMID: 31078123 DOI: 10.1016/j.ceb.2019.03.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 03/20/2019] [Accepted: 03/28/2019] [Indexed: 11/26/2022]
Abstract
This review highlights three recent trends in the field of kinetochore biology: the proliferation of structural data for kinetochore protein complexes (including CBF3, Dam1c, Mis12cMIND, and CENP-NLChl4/Iml3); the growing consensus that the kinetochore is a dynamic structure whose composition changes as the cell cycle progresses; and the mounting evidence of multiple pathways whereby the microtubule-binding elements of the outer kinetochore may be recruited by inner kinetochore proteins. Our focus is on the two best-studied systems in the field: human and budding yeast kinetochores. This review will demonstrate the remarkable similarity of these two systems, as well as their intriguing differences.
Collapse
Affiliation(s)
- Grace Hamilton
- Department of Biochemistry, University of Washington Box 357350, 1705 NE Pacific St., Seattle, WA 98195-7350, USA
| | - Yoana Dimitrova
- Genentech, Inc., 1 DNA Way, MS: 27, South San Francisco, CA 94080, USA
| | - Trisha N Davis
- Department of Biochemistry, University of Washington Box 357350, 1705 NE Pacific St., Seattle, WA 98195-7350, USA.
| |
Collapse
|
19
|
Zhang X, Hooykaas PJJ. The Agrobacterium VirD5 protein hyperactivates the mitotic Aurora kinase in host cells. THE NEW PHYTOLOGIST 2019; 222:1551-1560. [PMID: 30667529 PMCID: PMC6667905 DOI: 10.1111/nph.15700] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Accepted: 01/13/2019] [Indexed: 06/08/2023]
Abstract
Aided by translocated virulence proteins, Agrobacterium tumefaciens transforms plant cells with oncogenic T-DNA. In the host cells the virulence protein VirD5 moves to the nucleus, where it becomes localized at the kinetochores, and disturbs faithful chromosome segregation, but the molecular mechanism underlying this remains unknown. To gain more insight, we screened amongst the kinetochore proteins for VirD5 interactors using bimolecular fluorescence complementation assays, and tested chromosome segregation in yeast cells. We found that VirD5 interacts with the conserved mitotic Aurora kinase Ipl1 in yeast and likewise with plant Aurora kinases. In vitro VirD5 was found to stimulate the activity of Ipl1. Phosphorylation of substrates by Ipl1 in vivo is known to result in the detachment between kinetochore and spindle microtubule. This is necessary for error correction, but increased Ipl1/Aurora kinase activity is known to cause spindle instability, explaining enhanced chromosome mis-segregation seen in the presence of VirD5. That activation of the Ipl1/Aurora kinase at least partially underlies the toxicity of VirD5 became apparent by artificial boosting the activity of the specific counteracting phosphatase Glc7 in vivo, which relieved the toxicity. These findings reveal a novel mechanism by which a pathogenic bacterium manipulates host cells.
Collapse
Affiliation(s)
- Xiaorong Zhang
- Department of Molecular and Developmental GeneticsInstitute of BiologyLeiden UniversitySylviusweg 72Leiden2333BEthe Netherlands
| | - Paul J. J. Hooykaas
- Department of Molecular and Developmental GeneticsInstitute of BiologyLeiden UniversitySylviusweg 72Leiden2333BEthe Netherlands
| |
Collapse
|
20
|
Mittal P, Chavan A, Trakroo D, Shah S, Ghosh SK. Outer kinetochore protein Dam1 promotes centromere clustering in parallel with Slk19 in budding yeast. Chromosoma 2019; 128:133-148. [PMID: 30903360 DOI: 10.1007/s00412-019-00694-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2018] [Revised: 01/14/2019] [Accepted: 02/11/2019] [Indexed: 12/16/2022]
Abstract
A higher order organization of the centromeres in the form of clustering of these DNA loci has been observed in many organisms. While centromere clustering is biologically significant to achieve faithful chromosome segregation, the underlying molecular mechanism is yet to be fully understood. In budding yeast, a kinetochore-associated protein Slk19 is shown to have a role in clustering in association with the microtubules whereas removal of either Slk19 or microtubules alone does not have any effect on the centromere clustering. Furthermore, Slk19 is non-essential for growth and becomes cleaved during anaphase whereas clustering being an essential event occurs throughout the cell cycle. Hence, we searched for an additional factor involved in the clustering and since the integrity of the kinetochore complex is shown to be crucial for centromere clustering, we restricted our search within the complex. We observed that the outermost kinetochore protein Dam1 promotes centromere clustering through stabilization of the kinetochore integrity. While in the absence of Dam1 we failed to detect Slk19 at the centromere, on the other hand, we found almost no Dam1 at the centromere in the absence of Slk19 and microtubules suggesting interdependency between these two pathways. Strikingly, we observed that overexpression of Dam1 or Slk19 could restore the centromere clustering largely in the cells devoid of Slk19 and microtubules or Dam1, respectively. Thus, we propose that in budding yeast, centromere clustering is achieved at least by two parallel pathways, through Dam1 and another via Slk19, in concert with the microtubules suggesting that having a dual mechanism may be crucial for ensuring microtubule capture by the point centromeres where each attaches to only one microtubule.
Collapse
Affiliation(s)
- Priyanka Mittal
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Ankita Chavan
- Molecular and Cell Biology Department, University of Connecticut, Storrs, CT, 06269, USA
| | - Deepika Trakroo
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
| | - Sanket Shah
- Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, 410210, India
| | - Santanu K Ghosh
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India.
| |
Collapse
|
21
|
Glucose Signaling Is Connected to Chromosome Segregation Through Protein Kinase A Phosphorylation of the Dam1 Kinetochore Subunit in Saccharomyces cerevisiae. Genetics 2018; 211:531-547. [PMID: 30546002 DOI: 10.1534/genetics.118.301727] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 12/10/2018] [Indexed: 11/18/2022] Open
Abstract
The Dam1 complex is an essential component of the outer kinetochore that mediates attachments between spindle microtubules and chromosomes. Dam1p, a subunit of the Dam1 complex, binds to microtubules and is regulated by Aurora B/Ipl1p phosphorylation. We find that overexpression of cAMP-dependent protein kinase (PKA) catalytic subunits (i.e., TPK1, TPK2, TPK3) is lethal in DAM1 mutants and increases the rate of chromosome loss in wild-type cells. Replacing an evolutionarily conserved PKA site (S31) in Dam1p with a nonphosphorylatable alanine suppressed the high-copy PKA dosage lethality in dam1-1 Consistent with Dam1p as a target of PKA, we find that in vitro PKA can directly phosphorylate S31 in Dam1p and we observed phosphorylation of S31 in Dam1p purified from asynchronously growing yeast cells. Cells carrying high-copy TPK2 or a Dam1p phospho-mimetic S31D mutant displayed a reduction in Dam1p localization at the kinetochore, suggesting that PKA phosphorylation plays a role in assembly and/or stability of the Dam1 complex. Furthermore, we observed spindle defects associated with S31 phosphorylation. Finally, we find that phosphorylation of Dam1p on S31 is reduced when glucose is limiting as well as during α-factor arrest, conditions that inhibit PKA activity. These observations suggest that the PKA site of Dam1p participates in regulating kinetochore activity. While PKA is a well-established effector of glucose signaling, our work shows for the first time that glucose-dependent PKA activity has an important function in chromosome segregation.
Collapse
|
22
|
Llauró A, Hayashi H, Bailey ME, Wilson A, Ludzia P, Asbury CL, Akiyoshi B. The kinetoplastid kinetochore protein KKT4 is an unconventional microtubule tip-coupling protein. J Cell Biol 2018; 217:3886-3900. [PMID: 30209069 PMCID: PMC6219724 DOI: 10.1083/jcb.201711181] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 07/23/2018] [Accepted: 08/24/2018] [Indexed: 01/08/2023] Open
Abstract
The evolutionarily divergent class of kinetoplastid organisms has a set of unconventional kinetochore proteins that drive chromosome segregation, but it is unclear which components interact with spindle microtubules. Llauró et al. now identify KKT4 as the first microtubule-binding kinetochore protein in Trypanosoma brucei, a major human pathogenic parasite. Kinetochores are multiprotein machines that drive chromosome segregation by maintaining persistent, load-bearing linkages between chromosomes and dynamic microtubule tips. Kinetochores in commonly studied eukaryotes bind microtubules through widely conserved components like the Ndc80 complex. However, in evolutionarily divergent kinetoplastid species such as Trypanosoma brucei, which causes sleeping sickness, the kinetochores assemble from a unique set of proteins lacking homology to any known microtubule-binding domains. Here, we show that the T. brucei kinetochore protein KKT4 binds directly to microtubules and maintains load-bearing attachments to both growing and shortening microtubule tips. The protein localizes both to kinetochores and to spindle microtubules in vivo, and its depletion causes defects in chromosome segregation. We define a microtubule-binding domain within KKT4 and identify several charged residues important for its microtubule-binding activity. Thus, despite its lack of significant similarity to other known microtubule-binding proteins, KKT4 has key functions required for driving chromosome segregation. We propose that it represents a primary element of the kinetochore–microtubule interface in kinetoplastids.
Collapse
Affiliation(s)
- Aida Llauró
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Hanako Hayashi
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Megan E Bailey
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Alex Wilson
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Patryk Ludzia
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, WA
| | - Bungo Akiyoshi
- Department of Biochemistry, University of Oxford, Oxford, UK
| |
Collapse
|
23
|
Suzuki A, Gupta A, Long SK, Evans R, Badger BL, Salmon ED, Biggins S, Bloom K. A Kinesin-5, Cin8, Recruits Protein Phosphatase 1 to Kinetochores and Regulates Chromosome Segregation. Curr Biol 2018; 28:2697-2704.e3. [PMID: 30174190 DOI: 10.1016/j.cub.2018.08.038] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 08/02/2018] [Accepted: 08/16/2018] [Indexed: 01/03/2023]
Abstract
Kinesin-5 is a highly conserved homo-tetrameric protein complex responsible for crosslinking microtubules and pushing spindle poles apart. The budding yeast Kinesin-5, Cin8, is highly concentrated at kinetochores in mitosis before anaphase, but its functions there are largely unsolved. Here, we show that Cin8 localizes to kinetochores in a cell-cycle-dependent manner and concentrates near the microtubule binding domains of Ndc80 at metaphase. Cin8's kinetochore localization depends on the Ndc80 complex, kinetochore microtubules, and the Dam1 complex. Consistent with its kinetochore localization, a Cin8 deletion induces a loss of tension at the Ndc80 microtubule binding domains and a major delay in mitotic progression. Cin8 associates with Protein Phosphatase 1 (PP1), and mutants that inhibit its PP1 binding also induce a loss of tension at the Ndc80 microtubule binding domains and delay mitotic progression. Taken together, our results suggest that Cin8-PP1 plays a critical role at kinetochores to promote accurate chromosome segregation by controlling Ndc80 attachment to microtubules.
Collapse
Affiliation(s)
- Aussie Suzuki
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; McArdle Laboratory for Cancer Research, Department of Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI 53705, USA.
| | - Amitabha Gupta
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Sarah K Long
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Rena Evans
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Benjamin L Badger
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Edward D Salmon
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Sue Biggins
- Howard Hughes Medical Institute, Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| | - Kerry Bloom
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
24
|
Joglekar AP, Kukreja AA. How Kinetochore Architecture Shapes the Mechanisms of Its Function. Curr Biol 2018; 27:R816-R824. [PMID: 28829971 DOI: 10.1016/j.cub.2017.06.012] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The eukaryotic kinetochore is a sophisticated multi-protein machine that segregates chromosomes during cell division. To ensure accurate chromosome segregation, it performs three major functions using disparate molecular mechanisms. It operates a mechanosensitive signaling cascade known as the spindle assembly checkpoint (SAC) to detect and signal the lack of attachment to spindle microtubules, and delay anaphase onset in response. In addition, after attaching to spindle microtubules, the kinetochore generates the force necessary to move chromosomes. Finally, if the two sister kinetochores on a chromosome are both attached to microtubules emanating from the same spindle pole, they activate another mechanosensitive mechanism to correct the monopolar attachments. All three of these functions maintain genome stability during cell division. The outlines of the biochemical activities responsible for these functions are now available. How the kinetochore integrates the underlying molecular mechanisms is still being elucidated. In this Review, we discuss how the nanoscale protein organization in the kinetochore, which we refer to as kinetochore 'architecture', organizes its biochemical activities to facilitate the realization and integration of emergent mechanisms underlying its three major functions. For this discussion, we will use the relatively simple budding yeast kinetochore as a model, and extrapolate insights gained from this model to elucidate functional roles of the architecture of the much more complex human kinetochore.
Collapse
Affiliation(s)
- Ajit P Joglekar
- Department of Cell & Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Biophysics, University of Michigan, Ann Arbor, MI, USA.
| | | |
Collapse
|
25
|
McIntosh JR. Assessing the Contributions of Motor Enzymes and Microtubule Dynamics to Mitotic Chromosome Motions. Annu Rev Cell Dev Biol 2018; 33:1-22. [PMID: 28992437 DOI: 10.1146/annurev-cellbio-100616-060827] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
During my graduate work with Keith Porter, I became fascinated by the mitotic spindle, an interest that has motivated much of my scientific work ever since. I began spindle studies by using electron microscopes, instruments that have made significant contributions to our understanding of spindle organization. Such instruments have helped to elucidate the distributions of spindle microtubules, the interactions among them, their molecular polarity, and their associations with both kinetochores and spindle poles. Our lab has also investigated some processes of spindle physiology: microtubule dynamics, the actions of microtubule-associated proteins (including motor enzymes), the character of forces generated by specific spindle components, and factors that control mitotic progression. Here, I give a personal perspective on some of this intellectual history and on what recent discoveries imply about the mechanisms of chromosome motion.
Collapse
Affiliation(s)
- J Richard McIntosh
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado 80309-0347;
| |
Collapse
|
26
|
Human Ska complex and Ndc80 complex interact to form a load-bearing assembly that strengthens kinetochore-microtubule attachments. Proc Natl Acad Sci U S A 2018; 115:2740-2745. [PMID: 29487209 PMCID: PMC5856539 DOI: 10.1073/pnas.1718553115] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Microtubules are dynamic, tube-like structures that drive the segregation of duplicated chromosomes during cell division. The Ska complex is part of a molecular machine that forms force-bearing connections between chromosomes and microtubule ends. Depletion of the Ska complex destabilizes these connections and disrupts cell division. The Ska complex binds microtubules, but it is unknown whether it directly holds force at microtubules or indirectly stabilizes the connections. Here, we show that the Ska complex makes a direct force-bearing linkage with microtubule ends and assembles with another microtubule binding component, the Ndc80 complex, to strengthen its ability to withstand force. Our results suggest that the Ska and Ndc80 complexes work together to maintain the connections between chromosomes and microtubule ends. Accurate segregation of chromosomes relies on the force-bearing capabilities of the kinetochore to robustly attach chromosomes to dynamic microtubule tips. The human Ska complex and Ndc80 complex are outer-kinetochore components that bind microtubules and are required to fully stabilize kinetochore–microtubule attachments in vivo. While purified Ska complex tracks with disassembling microtubule tips, it remains unclear whether the Ska complex–microtubule interaction is sufficiently strong to make a significant contribution to kinetochore–microtubule coupling. Alternatively, Ska complex might affect kinetochore coupling indirectly, through recruitment of phosphoregulatory factors. Using optical tweezers, we show that the Ska complex itself bears load on microtubule tips, strengthens Ndc80 complex-based tip attachments, and increases the switching dynamics of the attached microtubule tips. Cross-linking mass spectrometry suggests the Ska complex directly binds Ndc80 complex through interactions between the Ska3 unstructured C-terminal region and the coiled-coil regions of each Ndc80 complex subunit. Deletion of the Ska complex microtubule-binding domain or the Ska3 C terminus prevents Ska complex from strengthening Ndc80 complex-based attachments. Together, our results indicate that the Ska complex can directly strengthen the kinetochore–microtubule interface and regulate microtubule tip dynamics by forming an additional connection between the Ndc80 complex and the microtubule.
Collapse
|
27
|
Meyer RE, Brown J, Beck L, Dawson DS. Mps1 promotes chromosome meiotic chromosome biorientation through Dam1. Mol Biol Cell 2017; 29:479-489. [PMID: 29237818 PMCID: PMC6014172 DOI: 10.1091/mbc.e17-08-0503] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/11/2022] Open
Abstract
During meiosis, chromosomes attach to microtubules at their kinetochores and are moved by microtubule depolymerization. The Mps1 kinase is essential for this process. Phosphorylation of Dam1 by Mps1 allows kinetochores to move processively poleward along microtubules during the biorientation process. In budding yeast meiosis, homologous chromosomes become linked by chiasmata and then move back and forth on the spindle until they are bioriented, with the kinetochores of the partners attached to microtubules from opposite spindle poles. Certain mutations in the conserved kinase, Mps1, result in catastrophic meiotic segregation errors but mild mitotic defects. We tested whether Dam1, a known substrate of Mps1, was necessary for its critical meiotic role. We found that kinetochore–microtubule attachments are established even when Dam1 is not phosphorylated by Mps1, but that Mps1 phosphorylation of Dam1 sustains those connections. But the meiotic defects when Dam1 is not phosphorylated are not nearly as catastrophic as when Mps1 is inactivated. The results demonstrate that one meiotic role of Mps1 is to stabilize connections that have been established between kinetochores and microtubles by phosphorylating Dam1.
Collapse
Affiliation(s)
- Régis E Meyer
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Jamin Brown
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Lindsay Beck
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| | - Dean S Dawson
- Program in Cell Cycle and Cancer Biology, Oklahoma Medical Research Foundation, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104 .,Department of Cell Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104
| |
Collapse
|
28
|
Humphrey L, Felzer-Kim I, Joglekar AP. Stu2 acts as a microtubule destabilizer in metaphase budding yeast spindles. Mol Biol Cell 2017; 29:247-255. [PMID: 29187578 PMCID: PMC5996951 DOI: 10.1091/mbc.e17-08-0494] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 11/15/2017] [Accepted: 11/21/2017] [Indexed: 01/22/2023] Open
Abstract
Stu2 colocalizes with budding yeast kinetochores by interacting with polymerizing microtubule plus ends. Furthermore, it destabilizes these plus ends. It is proposed that Stu2-mediated destabilization contributes indirectly to the “catch-bond” activity of yeast kinetochores. The microtubule-associated protein Stu2 (XMAP215) has the remarkable ability to act either as a polymerase or as a destabilizer of the microtubule plus end. In budding yeast, it is required for the dynamicity of spindle microtubules and also for kinetochore force generation. To understand how Stu2 contributes to these distinct activities, we analyzed the contributions of its functional domains to its localization and function. We find that Stu2 colocalizes with kinetochores using its TOG domains, which bind GTP-tubulin, a coiled-coil homodimerization domain, and a domain that interacts with plus-end interacting proteins. Stu2 localization is also promoted by phosphorylation at a putative CDK1 phosphorylation site located within its microtubule-binding basic patch. Surprisingly, however, we find that kinetochore force generation is uncorrelated with the amount of kinetochore-colocalized Stu2. These and other data imply that Stu2 colocalizes with kinetochores by recognizing growing microtubule plus ends within yeast kinetochores. We propose that Stu2 destabilizes these plus ends to indirectly contribute to the “catch-bond” activity of the kinetochores.
Collapse
Affiliation(s)
- Lauren Humphrey
- Cell and Developmental Biology, University of Michigan Medical School, University of Michigan, Ann Arbor, MI 48019
| | - Isabella Felzer-Kim
- Cell and Developmental Biology, University of Michigan Medical School, University of Michigan, Ann Arbor, MI 48019
| | - Ajit P Joglekar
- Cell and Developmental Biology, University of Michigan Medical School, University of Michigan, Ann Arbor, MI 48019 .,Department of Biophysics, University of Michigan, Ann Arbor, MI 48019
| |
Collapse
|
29
|
Dhatchinamoorthy K, Shivaraju M, Lange JJ, Rubinstein B, Unruh JR, Slaughter BD, Gerton JL. Structural plasticity of the living kinetochore. J Cell Biol 2017; 216:3551-3570. [PMID: 28939613 PMCID: PMC5674893 DOI: 10.1083/jcb.201703152] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 07/17/2017] [Accepted: 08/21/2017] [Indexed: 11/30/2022] Open
Abstract
Dhatchinamoorthy et al. use calibrated imaging, FRAP, and photoconversion to study the changes in kinetochore component copy numbers from G1 to anaphase and find that the Dam1 submodule is unchanged during anaphase, whereas MIND and Ndc80 submodules add copies, providing insight into the dynamics and plasticity of the kinetochore structure during chromosome segregation. The kinetochore is a large, evolutionarily conserved protein structure that connects chromosomes with microtubules. During chromosome segregation, outer kinetochore components track depolymerizing ends of microtubules to facilitate the separation of chromosomes into two cells. In budding yeast, each chromosome has a point centromere upon which a single kinetochore is built, which attaches to a single microtubule. This defined architecture facilitates quantitative examination of kinetochores during the cell cycle. Using three independent measures—calibrated imaging, FRAP, and photoconversion—we find that the Dam1 submodule is unchanged during anaphase, whereas MIND and Ndc80 submodules add copies to form an “anaphase configuration” kinetochore. Microtubule depolymerization and kinesin-related motors contribute to copy addition. Mathematical simulations indicate that the addition of microtubule attachments could facilitate tracking during rapid microtubule depolymerization. We speculate that the minimal kinetochore configuration, which exists from G1 through metaphase, allows for correction of misattachments. Our study provides insight into dynamics and plasticity of the kinetochore structure during chromosome segregation in living cells.
Collapse
Affiliation(s)
- Karthik Dhatchinamoorthy
- Stowers Institute for Medical Research, Kansas City, MO.,The Open University, Milton Keynes, England, UK
| | | | | | | | - Jay R Unruh
- Stowers Institute for Medical Research, Kansas City, MO
| | | | - Jennifer L Gerton
- Stowers Institute for Medical Research, Kansas City, MO .,Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS
| |
Collapse
|
30
|
Mps1 Regulates Kinetochore-Microtubule Attachment Stability via the Ska Complex to Ensure Error-Free Chromosome Segregation. Dev Cell 2017; 41:143-156.e6. [PMID: 28441529 DOI: 10.1016/j.devcel.2017.03.025] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Revised: 02/16/2017] [Accepted: 03/30/2017] [Indexed: 12/18/2022]
Abstract
The spindle assembly checkpoint kinase Mps1 not only inhibits anaphase but also corrects erroneous attachments that could lead to missegregation and aneuploidy. However, Mps1's error correction-relevant substrates are unknown. Using a chemically tuned kinetochore-targeting assay, we show that Mps1 destabilizes microtubule attachments (K fibers) epistatically to Aurora B, the other major error-correcting kinase. Through quantitative proteomics, we identify multiple sites of Mps1-regulated phosphorylation at the outer kinetochore. Substrate modification was microtubule sensitive and opposed by PP2A-B56 phosphatases that stabilize chromosome-spindle attachment. Consistently, Mps1 inhibition rescued K-fiber stability after depleting PP2A-B56. We also identify the Ska complex as a key effector of Mps1 at the kinetochore-microtubule interface, as mutations that mimic constitutive phosphorylation destabilized K fibers in vivo and reduced the efficiency of the Ska complex's conversion from lattice diffusion to end-coupled microtubule binding in vitro. Our results reveal how Mps1 dynamically modifies kinetochores to correct improper attachments and ensure faithful chromosome segregation.
Collapse
|
31
|
Asbury CL. Anaphase A: Disassembling Microtubules Move Chromosomes toward Spindle Poles. BIOLOGY 2017; 6:E15. [PMID: 28218660 PMCID: PMC5372008 DOI: 10.3390/biology6010015] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/04/2017] [Accepted: 02/10/2017] [Indexed: 11/16/2022]
Abstract
The separation of sister chromatids during anaphase is the culmination of mitosis and one of the most strikingly beautiful examples of cellular movement. It consists of two distinct processes: Anaphase A, the movement of chromosomes toward spindle poles via shortening of the connecting fibers, and anaphase B, separation of the two poles from one another via spindle elongation. I focus here on anaphase A chromosome-to-pole movement. The chapter begins by summarizing classical observations of chromosome movements, which support the current understanding of anaphase mechanisms. Live cell fluorescence microscopy studies showed that poleward chromosome movement is associated with disassembly of the kinetochore-attached microtubule fibers that link chromosomes to poles. Microtubule-marking techniques established that kinetochore-fiber disassembly often occurs through loss of tubulin subunits from the kinetochore-attached plus ends. In addition, kinetochore-fiber disassembly in many cells occurs partly through 'flux', where the microtubules flow continuously toward the poles and tubulin subunits are lost from minus ends. Molecular mechanistic models for how load-bearing attachments are maintained to disassembling microtubule ends, and how the forces are generated to drive these disassembly-coupled movements, are discussed.
Collapse
Affiliation(s)
- Charles L Asbury
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98195, USA.
| |
Collapse
|
32
|
Kim JO, Zelter A, Umbreit NT, Bollozos A, Riffle M, Johnson R, MacCoss MJ, Asbury CL, Davis TN. The Ndc80 complex bridges two Dam1 complex rings. eLife 2017; 6. [PMID: 28191870 PMCID: PMC5354518 DOI: 10.7554/elife.21069] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Accepted: 02/11/2017] [Indexed: 12/18/2022] Open
Abstract
Strong kinetochore-microtubule attachments are essential for faithful segregation of sister chromatids during mitosis. The Dam1 and Ndc80 complexes are the main microtubule binding components of the Saccharomyces cerevisiae kinetochore. Cooperation between these two complexes enhances kinetochore-microtubule coupling and is regulated by Aurora B kinase. We show that the Ndc80 complex can simultaneously bind and bridge across two Dam1 complex rings through a tripartite interaction, each component of which is regulated by Aurora B kinase. Mutations in any one of the Ndc80p interaction regions abrogates the Ndc80 complex's ability to bind two Dam1 rings in vitro, and results in kinetochore biorientation and microtubule attachment defects in vivo. We also show that an extra-long Ndc80 complex, engineered to space the two Dam1 rings further apart, does not support growth. Taken together, our work suggests that each kinetochore in vivo contains two Dam1 rings and that proper spacing between the rings is vital.
Collapse
Affiliation(s)
- Jae Ook Kim
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Alex Zelter
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Neil T Umbreit
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Athena Bollozos
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Michael Riffle
- Department of Biochemistry, University of Washington, Seattle, United States
| | - Richard Johnson
- Department of Genome Sciences, University of Washington, Seattle, United States
| | - Michael J MacCoss
- Department of Genome Sciences, University of Washington, Seattle, United States
| | - Charles L Asbury
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, United States
| |
Collapse
|
33
|
Hashemi Shabestari M, Meijering AEC, Roos WH, Wuite GJL, Peterman EJG. Recent Advances in Biological Single-Molecule Applications of Optical Tweezers and Fluorescence Microscopy. Methods Enzymol 2016; 582:85-119. [PMID: 28062046 DOI: 10.1016/bs.mie.2016.09.047] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Over the past two decades, single-molecule techniques have evolved into robust tools to study many fundamental biological processes. The combination of optical tweezers with fluorescence microscopy and microfluidics provides a powerful single-molecule manipulation and visualization technique that has found widespread application in biology. In this combined approach, the spatial (~nm) and temporal (~ms) resolution, as well as the force scale (~pN) accessible to optical tweezers is complemented with the power of fluorescence microscopy. Thereby, it provides information on the local presence, identity, spatial dynamics, and conformational dynamics of single biomolecules. Together, these techniques allow comprehensive studies of, among others, molecular motors, protein-protein and protein-DNA interactions, biomolecular conformational changes, and mechanotransduction pathways. In this chapter, recent applications of fluorescence microscopy in combination with optical trapping are discussed. After an introductory section, we provide a description of instrumentation together with the current capabilities and limitations of the approaches. Next we summarize recent studies that applied this combination of techniques in biological systems and highlight some representative biological assays to mark the exquisite opportunities that optical tweezers combined with fluorescence microscopy provide.
Collapse
Affiliation(s)
| | | | - W H Roos
- Moleculaire Biofysica, Zernike Institute, Rijksuniversiteit Groningen, Groningen, The Netherlands
| | - G J L Wuite
- Vrije Universiteit, Amsterdam, The Netherlands
| | | |
Collapse
|
34
|
Barlow NE, Bolognesi G, Flemming AJ, Brooks NJ, Barter LMC, Ces O. Multiplexed droplet Interface bilayer formation. LAB ON A CHIP 2016; 16:4653-4657. [PMID: 27831583 DOI: 10.1039/c6lc01011c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We present a simple method for the multiplexed formation of droplet interface bilayers (DIBs) using a mechanically operated linear acrylic chamber array. To demonstrate the functionality of the chip design, a lipid membrane permeability assay is performed. We show that multiple, symmetric DIBs can be created and separated using this robust low-cost approach.
Collapse
Affiliation(s)
- Nathan E Barlow
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
| | - Guido Bolognesi
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
| | - Anthony J Flemming
- Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire, RG42 6EY, UK.
| | - Nicholas J Brooks
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
| | - Laura M C Barter
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
| | - Oscar Ces
- Department of Chemistry, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK. and Institute of Chemical Biology, Imperial College London, Exhibition Road, South Kensington, London, SW7 2AZ, UK.
| |
Collapse
|
35
|
Kent IA, Lele TP. Microtubule-based force generation. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2016; 9. [PMID: 27562344 DOI: 10.1002/wnan.1428] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2016] [Revised: 07/20/2016] [Accepted: 07/30/2016] [Indexed: 11/11/2022]
Abstract
Microtubules are vital to many important cell processes, such as cell division, transport of cellular cargo, organelle positioning, and cell migration. Owing to their diverse functions, understanding microtubule function is an important part of cell biological research that can help in combating various diseases. For example, microtubules are an important target of chemotherapeutic drugs such as paclitaxel because of their pivotal role in cell division. Many functions of microtubules relate to the generation of mechanical forces. These forces are generally either a direct result of microtubule polymerization/depolymerization or generated by motor proteins that move processively along microtubules. In this review, we summarize recent efforts to quantify and model force generation by microtubules in the context of microtubule function. WIREs Nanomed Nanobiotechnol 2017, 9:e1428. doi: 10.1002/wnan.1428 For further resources related to this article, please visit the WIREs website.
Collapse
Affiliation(s)
- Ian A Kent
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida, Gainesville, FL, USA
| |
Collapse
|
36
|
Drinnenberg IA, Henikoff S, Malik HS. Evolutionary Turnover of Kinetochore Proteins: A Ship of Theseus? Trends Cell Biol 2016; 26:498-510. [PMID: 26877204 PMCID: PMC4914419 DOI: 10.1016/j.tcb.2016.01.005] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 01/15/2016] [Accepted: 01/19/2016] [Indexed: 10/22/2022]
Abstract
The kinetochore is a multiprotein complex that mediates the attachment of a eukaryotic chromosome to the mitotic spindle. The protein composition of kinetochores is similar across species as divergent as yeast and human. However, recent findings have revealed an unexpected degree of compositional diversity in kinetochores. For example, kinetochore proteins that are essential in some species have been lost in others, whereas new kinetochore proteins have emerged in other lineages. Even in lineages with similar kinetochore composition, individual kinetochore proteins have functionally diverged to acquire either essential or redundant roles. Thus, despite functional conservation, the repertoire of kinetochore proteins has undergone recurrent evolutionary turnover.
Collapse
Affiliation(s)
- Ines A Drinnenberg
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Current address: Chromatin Dynamics Unit, UMR2664, Institut Curie, Paris, France.
| | - Steven Henikoff
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA
| | - Harmit S Malik
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA; Howard Hughes Medical Institute, Fred Hutchinson Cancer Research Center, Seattle, WA 98109, USA.
| |
Collapse
|
37
|
Cojoc G, Roscioli E, Zhang L, García-Ulloa A, Shah JV, Berns MW, Pavin N, Cimini D, Tolić IM, Gregan J. Laser microsurgery reveals conserved viscoelastic behavior of the kinetochore. J Cell Biol 2016; 212:767-76. [PMID: 27002163 PMCID: PMC4810299 DOI: 10.1083/jcb.201506011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 02/25/2016] [Indexed: 11/29/2022] Open
Abstract
Accurate chromosome segregation depends on proper kinetochore-microtubule attachment. Upon microtubule interaction, kinetochores are subjected to forces generated by the microtubules. In this work, we used laser ablation to sever microtubules attached to a merotelic kinetochore, which is laterally stretched by opposing pulling forces exerted by microtubules, and inferred the mechanical response of the kinetochore from its length change. In both mammalian PtK1 cells and in the fission yeast Schizosaccharomyces pombe, kinetochores shortened after microtubule severing. Interestingly, the inner kinetochore-centromere relaxed faster than the outer kinetochore. Whereas in fission yeast all kinetochores relaxed to a similar length, in PtK1 cells the more stretched kinetochores remained more stretched. Simple models suggest that these differences arise because the mechanical structure of the mammalian kinetochore is more complex. Our study establishes merotelic kinetochores as an experimental model for studying the mechanical response of the kinetochore in live cells and reveals a viscoelastic behavior of the kinetochore that is conserved in yeast and mammalian cells.
Collapse
Affiliation(s)
- Gheorghe Cojoc
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Emanuele Roscioli
- Department of Biological Sciences and Biocomplexity Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Lijuan Zhang
- Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna, 1030 Vienna, Austria
| | - Alfonso García-Ulloa
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Jagesh V Shah
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
| | - Michael W Berns
- Beckman Laser Institute and University of California, Irvine, Irvine, CA 92612
| | - Nenad Pavin
- Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb, Croatia
| | - Daniela Cimini
- Department of Biological Sciences and Biocomplexity Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Iva M Tolić
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany Division of Molecular Biology, Ruđer Bošković Institute, 10000 Zagreb, Croatia
| | - Juraj Gregan
- Max F. Perutz Laboratories, Department of Chromosome Biology, University of Vienna, 1030 Vienna, Austria
| |
Collapse
|
38
|
Cairo L, Wozniak R. The Nuclear Transport Factor Kap121 Is Required for Stability of the Dam1 Complex and Mitotic Kinetochore Bi-orientation. Cell Rep 2016; 14:2440-50. [DOI: 10.1016/j.celrep.2016.02.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2015] [Revised: 11/04/2015] [Accepted: 02/04/2016] [Indexed: 12/30/2022] Open
|
39
|
Freitag M. The kinetochore interaction network (KIN) of ascomycetes. Mycologia 2016; 108:485-505. [PMID: 26908646 DOI: 10.3852/15-182] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 10/23/2015] [Indexed: 01/13/2023]
Abstract
Chromosome segregation relies on coordinated activity of a large assembly of proteins, the kinetochore interaction network (KIN). How conserved the underlying mechanisms driving the epigenetic phenomenon of centromere and kinetochore assembly and maintenance are remains unclear, even though various eukaryotic models have been studied. More than 50 different proteins, many in multiple copies, comprise the KIN or are associated with fungal centromeres and kinetochores. Proteins isolated from immune sera recognized centromeric regions on chromosomes and thus were named centromere proteins (CENPs). CENP-A, sometimes called centromere-specific H3 (CenH3), is incorporated into nucleosomes within or near centromeres. The constitutive centromere-associated network (CCAN) assembles on this specialized chromatin, likely based on specific interactions with and requiring presence of CENP-C. The outer kinetochore comprises the Knl1-Mis12-Ndc80 (KMN) protein complexes that connect CCAN to spindles, accomplished by binding and stabilizing microtubules (MTs) and in the process generating load-bearing assemblies for chromatid segregation. In most fungi the Dam1/DASH complex connects the KMN complexes to MTs. Fungi present a rich resource to investigate mechanistic commonalities but also differences in kinetochore architecture. While ascomycetes have sets of CCAN and KMN proteins that are conserved with those of budding yeast or metazoans, searching other major branches of the fungal kingdom revealed that CCAN proteins are poorly conserved at the primary sequence level. Several conserved binding motifs or domains within KMN complexes have been described recently, and these features of ascomycete KIN proteins are shared with most metazoan proteins. In addition, several ascomycete-specific domains have been identified here.
Collapse
Affiliation(s)
- Michael Freitag
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon 97331-7305
| |
Collapse
|
40
|
Zelter A, Bonomi M, Kim JO, Umbreit NT, Hoopmann MR, Johnson R, Riffle M, Jaschob D, MacCoss MJ, Moritz RL, Davis TN. The molecular architecture of the Dam1 kinetochore complex is defined by cross-linking based structural modelling. Nat Commun 2015; 6:8673. [PMID: 26560693 PMCID: PMC4660060 DOI: 10.1038/ncomms9673] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2015] [Accepted: 09/18/2015] [Indexed: 12/28/2022] Open
Abstract
Accurate segregation of chromosomes during cell division is essential. The Dam1 complex binds kinetochores to microtubules and its oligomerization is required to form strong attachments. It is a key target of Aurora B kinase, which destabilizes erroneous attachments allowing subsequent correction. Understanding the roles and regulation of the Dam1 complex requires structural information. Here we apply cross-linking/mass spectrometry and structural modelling to determine the molecular architecture of the Dam1 complex. We find microtubule attachment is accompanied by substantial conformational changes, with direct binding mediated by the carboxy termini of Dam1p and Duo1p. Aurora B phosphorylation of Dam1p C terminus weakens direct interaction with the microtubule. Furthermore, the Dam1p amino terminus forms an interaction interface between Dam1 complexes, which is also disrupted by phosphorylation. Our results demonstrate that Aurora B inhibits both direct interaction with the microtubule and oligomerization of the Dam1 complex to drive error correction during mitosis.
Collapse
Affiliation(s)
- Alex Zelter
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | | | - Jae Ook Kim
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Neil T Umbreit
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | | | - Richard Johnson
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Michael Riffle
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Daniel Jaschob
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Michael J MacCoss
- Department of Genome Sciences, University of Washington, Seattle, Washington 98195, USA
| | - Robert L Moritz
- Institute for Systems Biology, Seattle, Washington 98109, USA
| | - Trisha N Davis
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| |
Collapse
|
41
|
Regulation of outer kinetochore Ndc80 complex-based microtubule attachments by the central kinetochore Mis12/MIND complex. Proc Natl Acad Sci U S A 2015; 112:E5583-9. [PMID: 26430240 DOI: 10.1073/pnas.1513882112] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Multiple protein subcomplexes of the kinetochore cooperate as a cohesive molecular unit that forms load-bearing microtubule attachments that drive mitotic chromosome movements. There is intriguing evidence suggesting that central kinetochore components influence kinetochore-microtubule attachment, but the mechanism remains unclear. Here, we find that the conserved Mis12/MIND (Mtw1, Nsl1, Nnf1, Dsn1) and Ndc80 (Ndc80, Nuf2, Spc24, Spc25) complexes are connected by an extensive network of contacts, each essential for viability in cells, and collectively able to withstand substantial tensile load. Using a single-molecule approach, we demonstrate that an individual MIND complex enhances the microtubule-binding affinity of a single Ndc80 complex by fourfold. MIND itself does not bind microtubules. Instead, MIND binds Ndc80 complex far from the microtubule-binding domain and confers increased microtubule interaction of the complex. In addition, MIND activation is redundant with the effects of a mutation in Ndc80 that might alter its ability to adopt a folded conformation. Together, our results suggest a previously unidentified mechanism for regulating microtubule binding of an outer kinetochore component by a central kinetochore complex.
Collapse
|
42
|
Abstract
A universal feature of mitosis is that all chromosomes become aligned at the spindle equator--the halfway point between the two spindle poles--prior to anaphase onset. This migratory event is called congression, and is powered by centromere-bound protein machines called kinetochores. This Commentary aims to document recent advances concerning the two kinetochore-based force-generating mechanisms that drive mitotic chromosome congression in vertebrate cells: depolymerisation-coupled pulling (DCP) and lateral sliding. We aim to explore how kinetochores can 'read-out' their spatial position within the spindle, and adjust these force-generating mechanisms to ensure chromosomes reach, and then remain, at the equator. Finally, we will describe the 'life history' of a chromosome, and provide a working model for how individual mechanisms are integrated to ensure efficient and successful congression.
Collapse
Affiliation(s)
- Philip Auckland
- Mechanochemical Cell Biology Building, Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| | - Andrew D McAinsh
- Mechanochemical Cell Biology Building, Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Coventry CV4 7AL, UK
| |
Collapse
|