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Mytlis A, Levy K, Elkouby YM. The many faces of the bouquet centrosome MTOC in meiosis and germ cell development. Curr Opin Cell Biol 2023; 81:102158. [PMID: 36913831 DOI: 10.1016/j.ceb.2023.102158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/28/2022] [Accepted: 02/12/2023] [Indexed: 03/13/2023]
Abstract
Meiotic chromosomal pairing is facilitated by a conserved cytoskeletal organization. Telomeres associate with perinuclear microtubules via Sun/KASH complexes on the nuclear envelope (NE) and dynein. Telomere sliding on perinuclear microtubules contributes to chromosome homology searches and is essential for meiosis. Telomeres ultimately cluster on the NE, facing the centrosome, in a configuration called the chromosomal bouquet. Here, we discuss novel components and functions of the bouquet microtubule organizing center (MTOC) in meiosis, but also broadly in gamete development. The cellular mechanics of chromosome movements and the bouquet MTOC dynamics are striking. The newly identified zygotene cilium mechanically anchors the bouquet centrosome and completes the bouquet MTOC machinery in zebrafish and mice. We hypothesize that various centrosome anchoring strategies evolved in different species. Evidence suggests that the bouquet MTOC machinery is a cellular organizer, linking meiotic mechanisms with gamete development and morphogenesis. We highlight this cytoskeletal organization as a new platform for creating a holistic understanding of early gametogenesis, with direct implications to fertility and reproduction.
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Affiliation(s)
- Avishag Mytlis
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel
| | - Karine Levy
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel
| | - Yaniv M Elkouby
- Department of Developmental Biology and Cancer Research, The Hebrew University of Jerusalem Faculty of Medicine, Ein-Kerem Campus, Jerusalem, 9112102, Israel; Institute for Medical Research - Israel-Canada (IMRIC), Ein-Kerem Campus, Jerusalem 9112102, Israel.
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2
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Fujita I, Kimura A, Yamashita A. A force balance model for a cell size-dependent meiotic nuclear oscillation in fission yeast. EMBO Rep 2023; 24:e55770. [PMID: 36622644 PMCID: PMC9986818 DOI: 10.15252/embr.202255770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 12/09/2022] [Accepted: 12/14/2022] [Indexed: 01/10/2023] Open
Abstract
Fission yeast undergoes premeiotic nuclear oscillation, which is dependent on microtubules and is driven by cytoplasmic dynein. Although the molecular mechanisms have been analyzed, how a robust oscillation is generated despite the dynamic behaviors of microtubules has yet to be elucidated. Here, we show that the oscillation exhibits cell length-dependent frequency and requires a balance between microtubule and viscous drag forces, as well as proper microtubule dynamics. Comparison of the oscillations observed in living cells with a simulation model based on microtubule dynamic instability reveals that the period of oscillation correlates with cell length. Genetic alterations that reduce cargo size suggest that the nuclear movement depends on viscous drag forces. Deletion of a gene encoding Kinesin-8 inhibits microtubule catastrophe at the cell cortex and results in perturbation of oscillation, indicating that nuclear movement also depends on microtubule dynamic instability. Our findings link numerical parameters from the simulation model with cellular functions required for generating the oscillation and provide a basis for understanding the physical properties of microtubule-dependent nuclear movements.
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Affiliation(s)
- Ikumi Fujita
- Laboratory for Cell Asymmetry, Center for Biosystems Dynamics ResearchRIKENKobeJapan
| | - Akatsuki Kimura
- Cell Architecture LaboratoryNational Institute of GeneticsMishimaJapan
- Department of Genetics, School of Life ScienceSOKENDAI (The Graduate University for Advanced Studies)MishimaJapan
| | - Akira Yamashita
- Interdisciplinary Research UnitNational Institute for Basic BiologyOkazakiJapan
- Center for Low‐temperature Plasma SciencesNagoya UniversityNagoyaJapan
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3
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Hernández-Sánchez F, Peraza-Reyes L. Spatiotemporal Dynamic Regulation of Organelles During Meiotic Development, Insights From Fungi. Front Cell Dev Biol 2022; 10:886710. [PMID: 35547805 PMCID: PMC9081346 DOI: 10.3389/fcell.2022.886710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 04/08/2022] [Indexed: 12/02/2022] Open
Abstract
Eukaryotic cell development involves precise regulation of organelle activity and dynamics, which adapt the cell architecture and metabolism to the changing developmental requirements. Research in various fungal model organisms has disclosed that meiotic development involves precise spatiotemporal regulation of the formation and dynamics of distinct intracellular membrane compartments, including peroxisomes, mitochondria and distinct domains of the endoplasmic reticulum, comprising its peripheral domains and the nuclear envelope. This developmental regulation implicates changes in the constitution and dynamics of these organelles, which modulate their structure, abundance and distribution. Furthermore, selective degradation systems allow timely organelle removal at defined meiotic stages, and regulated interactions between membrane compartments support meiotic-regulated organelle dynamics. This dynamic organelle remodeling is implicated in conducting organelle segregation during meiotic differentiation, and defines quality control regulatory systems safeguarding the inheritance of functional membrane compartments, promoting meiotic cell rejuvenation. Moreover, organelle remodeling is important for proper activity of the cytoskeletal system conducting meiotic nucleus segregation, as well as for meiotic differentiation. The orchestrated regulation of organelle dynamics has a determinant contribution in the formation of the renewed genetically-diverse offspring of meiosis.
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4
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Hornak I, Rieger H. Stochastic model of T Cell repolarization during target elimination (II). Biophys J 2022; 121:1246-1265. [PMID: 35196513 PMCID: PMC9034251 DOI: 10.1016/j.bpj.2022.02.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Revised: 08/08/2021] [Accepted: 02/16/2022] [Indexed: 11/16/2022] Open
Abstract
Cytotoxic T lymphocytes (T cells) and natural killer cells form a tight contact, the immunological synapse (IS), with target cells, where they release their lytic granules containing perforin/granzyme and cytokine-containing vesicles. During this process the cell repolarizes and moves the microtubule organizing center (MTOC) toward the IS. In the first part of our work we developed a computational model for the molecular-motor-driven motion of the microtubule cytoskeleton during T cell polarization and analyzed the effects of cortical-sliding and capture-shrinkage mechanisms. Here we use this model to analyze the dynamics of the MTOC repositioning in situations in which 1) the IS is in an arbitrary position with respect to the initial position of the MTOC and 2) the T cell has two IS at two arbitrary positions. In the case of one IS, we found that the initial position determines which mechanism is dominant and that the time of repositioning does not rise monotonously with the MTOC-IS distance. In the case of two IS, we observe several scenarios that have also been reported experimentally: the MTOC alternates stochastically (but with a well-defined average transition time) between the two IS; it wiggles in between the two IS without transiting to one of the two; or it is at some point pulled to one of the two IS and stays there. Our model allows one to predict which scenario emerges in dependency of the mechanisms in action and the number of dyneins present. We report that the presence of capture-shrinkage mechanism in at least one IS is necessary to assure the transitions in every cell configuration. Moreover, the frequency of transitions does not decrease with the distance between the two IS and is the highest when both mechanisms are present in both IS.
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Affiliation(s)
- Ivan Hornak
- Department of Theoretical Physics, Center for Biophysics, Saarland University, Saarbrücken, Germany.
| | - Heiko Rieger
- Department of Theoretical Physics, Center for Biophysics, Saarland University, Saarbrücken, Germany
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5
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Anderson HL, Casler JC, Lackner LL. Hierarchical integration of mitochondrial and nuclear positioning pathways by the Num1 EF hand. Mol Biol Cell 2022; 33:ar20. [PMID: 34985939 PMCID: PMC9236139 DOI: 10.1091/mbc.e21-12-0610-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: 11/16/2022] Open
Abstract
Positioning organelles at the right place and time is critical for their function and inheritance. In budding yeast, mitochondrial and nuclear positioning require the anchoring of mitochondria and dynein to the cell cortex by clusters of Num1. We have previously shown that mitochondria drive the assembly of cortical Num1 clusters, which then serve as anchoring sites for mitochondria and dynein. When mitochondrial inheritance is inhibited, mitochondrial-driven assembly of Num1 in buds is disrupted and defects in dynein-mediated spindle positioning are observed. Using a structure-function approach to dissect the mechanism of mitochondria-dependent dynein anchoring, we found that the EF hand–like motif (EFLM) of Num1 and its ability to bind calcium are required to bias dynein anchoring on mitochondria-associated Num1 clusters. Consistently, when the EFLM is disrupted, we no longer observe defects in dynein activity following inhibition of mitochondrial inheritance. Thus, the Num1 EFLM functions to bias dynein anchoring and activity in nuclear inheritance subsequent to mitochondrial inheritance. We hypothesize that this hierarchical integration of organelle positioning pathways by the Num1 EFLM contributes to the regulated order of organelle inheritance during the cell cycle.
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Affiliation(s)
- Heidi L Anderson
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Jason C Casler
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
| | - Laura L Lackner
- Department of Molecular Biosciences, Northwestern University, Evanston, IL, 60208, USA
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6
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Hondo Y, Azumi Y. Fluorescent In Situ Hybridization of 25S rDNA and Telomere Probes in the Lamium amplexicaule Chromosomes and their Signals Behavior during Meiosis. CYTOLOGIA 2021. [DOI: 10.1508/cytologia.86.155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Yuki Hondo
- Department of Biological Sciences, Faculty of Science, Kanagawa University
| | - Yoshitaka Azumi
- Department of Biological Sciences, Faculty of Science, Kanagawa University
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7
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Xiang X, Qiu R. Cargo-Mediated Activation of Cytoplasmic Dynein in vivo. Front Cell Dev Biol 2020; 8:598952. [PMID: 33195284 PMCID: PMC7649786 DOI: 10.3389/fcell.2020.598952] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/07/2020] [Indexed: 12/12/2022] Open
Abstract
Cytoplasmic dynein-1 is a minus-end-directed microtubule motor that transports a variety of cargoes including early endosomes, late endosomes and other organelles. In many cell types, dynein accumulates at the microtubule plus end, where it interacts with its cargo to be moved toward the minus end. Dynein binds to its various cargoes via the dynactin complex and specific cargo adapters. Dynactin and some of the coiled-coil-domain-containing cargo adapters not only link dynein to cargo but also activate dynein motility, which implies that dynein is activated by its cellular cargo. Structural studies indicate that a dynein dimer switches between the autoinhibited phi state and an open state; and the binding of dynactin and a cargo adapter to the dynein tails causes the dynein motor domains to have a parallel configuration, allowing dynein to walk processively along a microtubule. Recently, the dynein regulator LIS1 has been shown to be required for dynein activation in vivo, and its mechanism of action involves preventing dynein from switching back to the autoinhibited state. In this review, we will discuss our current understanding of dynein activation and point out the gaps of knowledge on the spatial regulation of dynein in live cells. In addition, we will emphasize the importance of studying a complete set of dynein regulators for a better understanding of dynein regulation in vivo.
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Affiliation(s)
- Xin Xiang
- Department of Biochemistry and Molecular Biology, The Uniformed Services University of the Health Sciences - F. Edward Hébert School of Medicine, Bethesda, MD, United States
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8
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Omer S, Brock K, Beckford J, Lee WL. Overexpression of Mdm36 reveals Num1 foci that mediate dynein-dependent microtubule sliding in budding yeast. J Cell Sci 2020; 133:jcs246363. [PMID: 32938686 PMCID: PMC7578358 DOI: 10.1242/jcs.246363] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 09/01/2020] [Indexed: 01/21/2023] Open
Abstract
The current model for spindle positioning requires attachment of the microtubule (MT) motor cytoplasmic dynein to the cell cortex, where it generates pulling force on astral MTs to effect spindle displacement. How dynein is anchored by cortical attachment machinery to generate large spindle-pulling forces remains unclear. Here, we show that cortical clustering of Num1, the yeast dynein attachment molecule, is limited by its assembly factor Mdm36. Overexpression of Mdm36 results in an overall enhancement of Num1 clustering but reveals a population of dim Num1 clusters that mediate dynein anchoring at the cell cortex. Direct imaging shows that bud-localized, dim Num1 clusters containing around only six Num1 molecules mediate dynein-dependent spindle pulling via a lateral MT sliding mechanism. Mutations affecting Num1 clustering interfere with mitochondrial tethering but do not interfere with the dynein-based spindle-pulling function of Num1. We propose that formation of small ensembles of attachment molecules is sufficient for dynein anchorage and cortical generation of large spindle-pulling forces.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Safia Omer
- Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03755, USA
| | - Katia Brock
- Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03755, USA
| | - John Beckford
- Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03755, USA
| | - Wei-Lih Lee
- Department of Biological Sciences, Dartmouth College, 78 College Street, Hanover, NH 03755, USA
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9
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Abstract
Meiosis is the basis of the generative reproduction of eukaryotes. The crucial first step is homologous chromosome pairing. In higher eukaryotes, micrometer-scale chromosomes, micrometer distances apart, are brought together by nanometer DNA sequences, at least a factor of 1000 size difference. Models of homology search, homologue movement, and pairing at the DNA level in higher eukaryotes are primarily based on studies with yeast where the emphasis is on the induction and repair of DNA double-strand breaks (DSB). For such a model, the very large nuclei of most plants and animals present serious problems. Homology search without DSBs cannot be explained by models based on DSB repair. The movement of homologues to meet each other and make contact at the molecular level is not understood. These problems are discussed and the conclusion is that at present practically nothing is known of meiotic homologue pairing in higher eukaryotes up to the formation of the synaptonemal complex, and that new, necessarily speculative models must be developed. Arguments are given that RNA plays a central role in homology search and a tentative model involving RNA in homology search is presented. A role of actin in homologue movement is proposed. The primary role of DSBs in higher eukaryotes is concluded to not be in paring but in the preparation of Holliday junctions, ultimately leading to chromatid exchange.
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Affiliation(s)
- J Sybenga
- Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands.,Laboratory of Genetics, Wageningen University, Wageningen, the Netherlands
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10
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Hornak I, Rieger H. Stochastic Model of T Cell Repolarization during Target Elimination I. Biophys J 2020; 118:1733-1748. [PMID: 32130873 DOI: 10.1016/j.bpj.2020.01.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/27/2020] [Accepted: 01/30/2020] [Indexed: 12/16/2022] Open
Abstract
Cytotoxic T lymphocytes (T) and natural killer cells are the main cytotoxic killer cells of the human body to eliminate pathogen-infected or tumorigenic cells (i.e., target cells). Once a natural killer or T cell has identified a target cell, they form a tight contact zone, the immunological synapse (IS). One then observes a repolarization of the cell involving the rotation of the microtubule (MT) cytoskeleton and a movement of the MT organizing center (MTOC) to a position that is just underneath the plasma membrane at the center of the IS. Concomitantly, a massive relocation of organelles attached to MTs is observed, including the Golgi apparatus, lytic granules, and mitochondria. Because the mechanism of this relocation is still elusive, we devise a theoretical model for the molecular-motor-driven motion of the MT cytoskeleton confined between plasma membrane and nucleus during T cell polarization. We analyze different scenarios currently discussed in the literature, the cortical sliding and capture-shrinkage mechanisms, and compare quantitative predictions about the spatiotemporal evolution of MTOC position and MT cytoskeleton morphology with experimental observations. The model predicts the experimentally observed biphasic nature of the repositioning due to an interplay between MT cytoskeleton geometry and motor forces and confirms the dominance of the capture-shrinkage over the cortical sliding mechanism when the MTOC and IS are initially diametrically opposed. We also find that the two mechanisms act synergistically, thereby reducing the resources necessary for repositioning. Moreover, it turns out that the localization of dyneins in the peripheral supramolecular activation cluster facilitates their interaction with the MTs. Our model also opens a way to infer details of the dynein distribution from the experimentally observed features of the MT cytoskeleton dynamics. In a subsequent publication, we will address the issue of general initial configurations and situations in which the T cell established two ISs.
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Affiliation(s)
- Ivan Hornak
- Center for Biophysics (ZBP) and Department of Theoretical Physics, Saarland University, Saarbrücken, Germany
| | - Heiko Rieger
- Center for Biophysics (ZBP) and Department of Theoretical Physics, Saarland University, Saarbrücken, Germany.
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11
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Tirumala NA, Ananthanarayanan V. Role of Dynactin in the Intracellular Localization and Activation of Cytoplasmic Dynein. Biochemistry 2019; 59:156-162. [PMID: 31591892 DOI: 10.1021/acs.biochem.9b00772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cytoplasmic dynein, the major minus end-directed motor protein in several cell types, transports a variety of intracellular cargo upon forming a processive tripartite complex with its activator dynactin and cargo adaptors such as Hook3 and BicD2. Our current understanding of dynein regulation stems from a combination of in vivo studies of cargo movement upon perturbation of dynein activity, in vitro single-molecule experiments, and cryo-electron microscopy studies of dynein structure and its interaction with dynactin and cargo adaptors. In this Perspective, we first consolidate data from recent publications to understand how perturbations to the dynein-dynactin interaction and dynactin's in vivo localization alter the behavior of dynein-driven cargo transport in a cell type- and experimental condition-specific manner. In addition, we touch upon results from in vivo and in vitro studies to elucidate how dynein's interaction with dynactin and cargo adaptors activates dynein and enhances its processivity. Finally, we propose questions that need to be addressed in the future with appropriate experimental designs so as to improve our understanding of the spatiotemporal regulation of dynein's function in the context of the distribution and dynamics of dynactin in living cells.
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12
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Chacko LA, Mehta K, Ananthanarayanan V. Cortical tethering of mitochondria by the anchor protein Mcp5 enables uniparental inheritance. J Cell Biol 2019; 218:3560-3571. [PMID: 31582398 PMCID: PMC6829665 DOI: 10.1083/jcb.201901108] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 05/31/2019] [Accepted: 08/20/2019] [Indexed: 12/16/2022] Open
Abstract
Paternal mitochondria are removed during eukaryotic sexual reproduction to ensure maternal mitochondrial inheritance. Chacko et al. show that fission yeast uses an anchor protein to physically separate and tether parental mitochondria to the cortex during meiosis, thereby achieving uniparental mitochondrial inheritance. During sexual reproduction in eukaryotes, processes such as active degradation and dilution of paternal mitochondria ensure maternal mitochondrial inheritance. In the isogamous organism fission yeast, we employed high-resolution fluorescence microscopy to visualize mitochondrial inheritance during meiosis by differentially labeling mitochondria of the two parental cells. Remarkably, mitochondria, and thereby mitochondrial DNA from the parental cells, did not mix upon zygote formation but remained segregated at the poles by attaching to clusters of the anchor protein Mcp5 via its coiled-coil domain. We observed that this tethering of parental mitochondria to the poles results in uniparental inheritance of mitochondria, wherein two of the four spores formed subsequently contained mitochondria from one parent and the other spores contained mitochondria from the other parent. Further, the presence of dynein on an Mcp5 cluster precluded the attachment of mitochondria to the same cluster. Taken together, we reveal a distinct mechanism that achieves uniparental inheritance by segregation of parental mitochondria.
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Affiliation(s)
- Leeba Ann Chacko
- Centre for BioSystems Science and Engineering, Indian Institute of Science, Bangalore, India
| | - Kritika Mehta
- Centre for BioSystems Science and Engineering, Indian Institute of Science, Bangalore, India
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13
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Abstract
Mitochondrial anchors have functions that extend beyond simply positioning mitochondria. In budding yeast, mitochondria drive the assembly of the mitochondrial anchor protein Num1 into clusters, which serve to anchor mitochondria as well as dynein to the cell cortex. Here, we explore a conserved role for mitochondria in dynein anchoring by examining the tethering functions of the evolutionarily distant Schizosaccharomyces pombe Num1 homologue. In addition to its function in dynein anchoring, we find that S. pombe Num1, also known as Mcp5, interacts with and tethers mitochondria to the plasma membrane in S. pombe and Saccharomyces cerevisiae. Thus, the mitochondria and plasma membrane-binding domains of the Num1 homologues, as well as the membrane features these domains recognize, are conserved. In S. pombe, we find that mitochondria impact the assembly and cellular distribution of Num1 clusters and that Num1 clusters actively engaged in mitochondrial tethering serve as cortical attachment sites for dynein. Thus, mitochondria play a critical and conserved role in the formation and distribution of dynein-anchoring sites at the cell cortex and, as a consequence, impact dynein function. These findings shed light on an ancient mechanism of mitochondria-dependent dynein anchoring that is conserved over more than 450 million years of evolution, raising the intriguing possibility that the role mitochondria play in dynein anchoring and function extends beyond yeast to higher eukaryotes.
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Affiliation(s)
- Lauren M Kraft
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Laura L Lackner
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
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14
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Xiang X. Nuclear movement in fungi. Semin Cell Dev Biol 2017; 82:3-16. [PMID: 29241689 DOI: 10.1016/j.semcdb.2017.10.024] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 10/17/2017] [Accepted: 10/23/2017] [Indexed: 12/22/2022]
Abstract
Nuclear movement within a cell occurs in a variety of eukaryotic organisms including yeasts and filamentous fungi. Fungal molecular genetic studies identified the minus-end-directed microtubule motor cytoplasmic dynein as a critical protein for nuclear movement or orientation of the mitotic spindle contained in the nucleus. Studies in the budding yeast first indicated that dynein anchored at the cortex via its anchoring protein Num1 exerts pulling force on an astral microtubule to orient the anaphase spindle across the mother-daughter axis before nuclear division. Prior to anaphase, myosin V interacts with the plus end of an astral microtubule via Kar9-Bim1/EB1 and pulls the plus end along the actin cables to move the nucleus/spindle close to the bud neck. In addition, pushing or pulling forces generated from cortex-linked polymerization or depolymerization of microtubules drive nuclear movements in yeasts and possibly also in filamentous fungi. In filamentous fungi, multiple nuclei within a hyphal segment undergo dynein-dependent back-and-forth movements and their positioning is also influenced by cytoplasmic streaming toward the hyphal tip. In addition, nuclear movement occurs at various stages of fungal development and fungal infection of plant tissues. This review discusses our current understanding on the mechanisms of nuclear movement in fungal organisms, the importance of nuclear positioning and the regulatory strategies that ensure the proper positioning of nucleus/spindle.
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Affiliation(s)
- Xin Xiang
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences - F. Edward Hébert School of Medicine, Bethesda, MD, USA.
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15
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Barbosa DJ, Duro J, Prevo B, Cheerambathur DK, Carvalho AX, Gassmann R. Dynactin binding to tyrosinated microtubules promotes centrosome centration in C. elegans by enhancing dynein-mediated organelle transport. PLoS Genet 2017; 13:e1006941. [PMID: 28759579 PMCID: PMC5552355 DOI: 10.1371/journal.pgen.1006941] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 08/10/2017] [Accepted: 07/25/2017] [Indexed: 12/01/2022] Open
Abstract
The microtubule-based motor dynein generates pulling forces for centrosome centration and mitotic spindle positioning in animal cells. How the essential dynein activator dynactin regulates these functions of the motor is incompletely understood. Here, we dissect the role of dynactin's microtubule binding activity, located in the p150 CAP-Gly domain and an adjacent basic patch, in the C. elegans zygote. Analysis of p150 mutants engineered by genome editing suggests that microtubule tip tracking of dynein-dynactin is dispensable for targeting the motor to the cell cortex and for generating robust cortical pulling forces. Instead, mutations in p150's CAP-Gly domain inhibit cytoplasmic pulling forces responsible for centration of centrosomes and attached pronuclei. The centration defects are mimicked by mutations of α-tubulin's C-terminal tyrosine, and both p150 CAP-Gly and tubulin tyrosine mutants decrease the frequency of early endosome transport from the cell periphery towards centrosomes during centration. Our results suggest that p150 GAP-Gly domain binding to tyrosinated microtubules promotes initiation of dynein-mediated organelle transport in the dividing one-cell embryo, and that this function of p150 is critical for generating cytoplasmic pulling forces for centrosome centration.
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Affiliation(s)
- Daniel J. Barbosa
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Joana Duro
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Bram Prevo
- Ludwig Institute for Cancer Research/Dept of Cellular & Molecular Medicine UCSD, La Jolla, CA, United States of America
| | - Dhanya K. Cheerambathur
- Ludwig Institute for Cancer Research/Dept of Cellular & Molecular Medicine UCSD, La Jolla, CA, United States of America
| | - Ana X. Carvalho
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
| | - Reto Gassmann
- Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Investigação e Inovação em Saúde (I3S), Universidade do Porto, Porto, Portugal
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16
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Fission yeast myosin I facilitates PI(4,5)P 2-mediated anchoring of cytoplasmic dynein to the cortex. Proc Natl Acad Sci U S A 2017; 114:E2672-E2681. [PMID: 28292899 DOI: 10.1073/pnas.1615883114] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Several key processes in the cell, such as vesicle transport and spindle positioning, are mediated by the motor protein cytoplasmic dynein, which produces force on the microtubule. For the functions that require movement of the centrosome and the associated nuclear material, dynein needs to have a stable attachment at the cell cortex. In fission yeast, Mcp5 is the anchor protein of dynein and is required for the oscillations of the horsetail nucleus during meiotic prophase. Although the role of Mcp5 in anchoring dynein to the cortex has been identified, it is unknown how Mcp5 associates with the membrane as well as the importance of the underlying attachment to the nuclear oscillations. Here, we set out to quantify Mcp5 organization and identify the binding partner of Mcp5 at the membrane. We used confocal and total internal reflection fluorescence microscopy to count the number of Mcp5 foci and the number of Mcp5 molecules in an individual focus. Further, we quantified the localization pattern of Mcp5 in fission yeast zygotes and show by perturbation of phosphatidylinositol 4-phosphate 5-kinase that Mcp5 binds to phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Remarkably, we discovered that the myosin I protein in fission yeast, Myo1, which is required for organization of sterol-rich domains in the cell membrane, facilitates the localization of Mcp5 and that of cytoplasmic dynein on the membrane. Finally, we demonstrate that Myo1-facilitated association of Mcp5 and dynein to the membrane determines the dynamics of nuclear oscillations and, in essence, dynein activity.
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Ananthanarayanan V. Activation of the motor protein upon attachment: Anchors weigh in on cytoplasmic dynein regulation. Bioessays 2016; 38:514-25. [PMID: 27143631 DOI: 10.1002/bies.201600002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cytoplasmic dynein is the major minus-end-directed motor protein in eukaryotes, and has functions ranging from organelle and vesicle transport to spindle positioning and orientation. The mode of regulation of dynein in the cell remains elusive, but a tantalising possibility is that dynein is maintained in an inhibited, non-motile state until bound to cargo. In vivo, stable attachment of dynein to the cell membrane via anchor proteins enables dynein to produce force by pulling on microtubules and serves to organise the nuclear material. Anchor proteins of dynein assume diverse structures and functions and differ in their interaction with the membrane. In yeast, the anchor protein has come to the fore as one of the key mediators of dynein activity. In other systems, much is yet to be discovered about the anchors, but future work in this area will prove invaluable in understanding dynein regulation in the cell.
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Kakui Y, Sato M. Differentiating the roles of microtubule-associated proteins at meiotic kinetochores during chromosome segregation. Chromosoma 2015; 125:309-20. [PMID: 26383111 DOI: 10.1007/s00412-015-0541-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 09/06/2015] [Accepted: 09/08/2015] [Indexed: 11/30/2022]
Abstract
Meiosis is a specialised cell division process for generating gametes. In contrast to mitosis, meiosis involves recombination followed by two consecutive rounds of cell division, meiosis I and II. A vast field of research has been devoted to understanding the differences between mitotic and meiotic cell divisions from the viewpoint of chromosome behaviour. For faithful inheritance of paternal and maternal genetic information to offspring, two events are indispensable: meiotic recombination, which generates a physical link between homologous chromosomes, and reductional segregation, in which homologous chromosomes move towards opposite poles, thereby halving the ploidy. The cytoskeleton and its regulators play specialised roles in meiosis to accomplish these divisions. Recent studies have shown that microtubule-associated proteins (MAPs), including tumour overexpressed gene (TOG), play unique roles during meiosis. Furthermore, the conserved mitotic protein kinase Polo modulates MAP localisation in meiosis I. As Polo is a well-known regulator of reductional segregation in meiosis, the evidence suggests that Polo constitutes a plausible link between meiosis-specific MAP functions and reductional segregation. Here, we review the latest findings on how the localisation and regulation of MAPs in meiosis differ from those in mitosis, and we discuss conservation of the system between yeast and higher eukaryotes.
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Affiliation(s)
- Yasutaka Kakui
- Chromosome Segregation Laboratory, The Francis Crick Institute, Lincoln's Inn Fields Laboratories, 44 Lincoln's Inn Fields, London, WC2A 3LY, UK.
| | - Masamitsu Sato
- Laboratory of Cytoskeletal Logistics, Department of Life Science and Medical Bioscience, Graduate School of Advanced Science and Engineering, Waseda University, TWIns, 2-2 Wakamatsucho, Shinjuku, Tokyo, 162-0056, Japan.
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Scheffler K, Minnes R, Fraisier V, Paoletti A, Tran PT. Microtubule minus end motors kinesin-14 and dynein drive nuclear congression in parallel pathways. ACTA ACUST UNITED AC 2015; 209:47-58. [PMID: 25869666 PMCID: PMC4395489 DOI: 10.1083/jcb.201409087] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Long-term imaging via microfluidic chambers shows that two minus end–directed motors, dynein and Klp2, work in parallel at distinct subcellular structures to promote efficient nuclear congression. Microtubules (MTs) and associated motors play a central role in nuclear migration, which is crucial for diverse biological functions including cell division, polarity, and sexual reproduction. In this paper, we report a dual mechanism underlying nuclear congression during fission yeast karyogamy upon mating of haploid cells. Using microfluidic chambers for long-term imaging, we captured the precise timing of nuclear congression and identified two minus end–directed motors operating in parallel in this process. Kinesin-14 Klp2 associated with MTs may cross-link and slide antiparallel MTs emanating from the two nuclei, whereas dynein accumulating at spindle pole bodies (SPBs) may pull MTs nucleated from the opposite SPB. Klp2-dependent nuclear congression proceeds at constant speed, whereas dynein accumulation results in an increase of nuclear velocity over time. Surprisingly, the light intermediate chain Dli1, but not dynactin, is required for this previously unknown function of dynein. We conclude that efficient nuclear congression depends on the cooperation of two minus end–directed motors.
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Affiliation(s)
- Kathleen Scheffler
- Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France
| | - Refael Minnes
- Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
| | - Vincent Fraisier
- Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France
| | - Anne Paoletti
- Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France
| | - Phong T Tran
- Centre de Recherche and BioImaging Cell and Tissue Core Facility of the Institut Curie (PICT-IBiSA), Institut Curie, F-75248 Paris, France Centre National de la Recherche Scientifique, Unite Mixte de Recherche 144, F-75248 Paris, France Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA 19104
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Fujita I, Yamashita A, Yamamoto M. Dynactin and Num1 cooperate to establish the cortical anchoring of cytoplasmic dynein in S. pombe. J Cell Sci 2015; 128:1555-67. [PMID: 25736293 DOI: 10.1242/jcs.163840] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 02/23/2015] [Indexed: 01/08/2023] Open
Abstract
Chromosome movement during meiosis is crucial for homologous pairing and meiotic recombination. During meiotic prophase in fission yeast, rapid nuclear migration is dependent on cytoplasmic dynein, which is anchored to the cell cortex and pulls microtubules, thereby driving nuclear migration. However, the precise mechanisms underlying dynein localization and activation remain unclear. Here, we identified three subunits of dynactin in fission yeast: Arp1, Mug5 and Jnm1 (also known as Mug1). These subunits transiently colocalized with dynein foci at the cell cortex and were essential for the cortical anchoring of dynein. Cortical factor Num1 (also known as Mcp5), which was also required for dynein anchoring, bound to dynein independently of dynactin. Whereas Num1 suppressed the sliding of dynein foci along the cortex, Arp1, Mug5 and Jnm1 were involved in the regulation of shrinkage and bundling of microtubules. From these data, we propose that dynein anchoring is established by cooperation of transient assembly of dynactin and function of Num1 at the cell cortex.
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Affiliation(s)
- Ikumi Fujita
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Laboratory for Cell Asymmetry, RIKEN Center for Developmental Biology, 2-2-3 Minatojima-minamimachi, Chuo-ku, Kobe, Hyogo 650-0047, Japan
| | - Akira Yamashita
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Laboratory of Cell Responses, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
| | - Masayuki Yamamoto
- Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan Laboratory of Cell Responses, National Institute for Basic Biology, Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Nishigonaka 38, Myodaiji, Okazaki, Aichi 444-8585, Japan
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Abstract
To exert forces, motor proteins bind with one end to cytoskeletal filaments, such as microtubules and actin, and with the other end to the cell cortex, a vesicle or another motor. A general question is how motors search for sites in the cell where both motor ends can bind to their respective binding partners. In the present review, we focus on cytoplasmic dynein, which is required for a myriad of cellular functions in interphase, mitosis and meiosis, ranging from transport of organelles and functioning of the mitotic spindle to chromosome movements in meiotic prophase. We discuss how dynein targets sites where it can exert a pulling force on the microtubule to transport cargo inside the cell.
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Ananthanarayanan V, Schattat M, Vogel SK, Krull A, Pavin N, Tolić-Nørrelykke IM. Dynein motion switches from diffusive to directed upon cortical anchoring. Cell 2013; 153:1526-36. [PMID: 23791180 DOI: 10.1016/j.cell.2013.05.020] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Revised: 04/09/2013] [Accepted: 05/08/2013] [Indexed: 11/18/2022]
Abstract
Cytoplasmic dynein is a motor protein that exerts force on microtubules. To generate force for the movement of large organelles, dynein needs to be anchored, with the anchoring sites being typically located at the cell cortex. However, the mechanism by which dyneins target sites where they can generate large collective forces is unknown. Here, we directly observe single dyneins during meiotic nuclear oscillations in fission yeast and identify the steps of the dynein binding process: from the cytoplasm to the microtubule and from the microtubule to cortical anchors. We observed that dyneins on the microtubule move either in a diffusive or directed manner, with the switch from diffusion to directed movement occurring upon binding of dynein to cortical anchors. This dual behavior of dynein on the microtubule, together with the two steps of binding, enables dyneins to self-organize into a spatial pattern needed for them to generate large collective forces.
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Transcriptional regulation of the copper transporter mfc1 in meiotic cells. EUKARYOTIC CELL 2013; 12:575-90. [PMID: 23397571 DOI: 10.1128/ec.00019-13] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Mfc1 is a meiosis-specific protein that mediates copper transport during the meiotic program in Schizosaccharomyces pombe. Although the mfc1(+) gene is induced at the transcriptional level in response to copper deprivation, the molecular determinants that are required for its copper starvation-dependent induction are unknown. Promoter deletion and site-directed mutagenesis have allowed identification of a new cis-regulatory element in the promoter region of the mfc1(+) gene. This cis-acting regulatory sequence containing the sequence TCGGCG is responsible for transcriptional activation of mfc1(+) under low-copper conditions. The TCGGCG sequence contains a CGG triplet known to serve as a binding site for members of the Zn(2)Cys(6) binuclear cluster transcriptional regulator family. In agreement with this fact, one member of this group of regulators, denoted Mca1, was found to be required for maximum induction of mfc1(+) gene expression. Analysis of Mca1 cellular distribution during meiosis revealed that it colocalizes with both chromosomes and sister chromatids during early, middle, and late phases of the meiotic program. Cells lacking Mca1 exhibited a meiotic arrest at metaphase I under low-copper conditions. Binding studies revealed that the N-terminal 150-residue segment of Mca1 expressed as a fusion protein in Escherichia coli specifically interacts with the TCGGCG sequence of the mfc1(+) promoter. Taken together, these results identify the cis-regulatory TCGGCG sequence and the transcription factor Mca1 as critical components for activation of the meiotic copper transport mfc1(+) gene in response to copper starvation.
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Tang X, Germain BS, Lee WL. A novel patch assembly domain in Num1 mediates dynein anchoring at the cortex during spindle positioning. ACTA ACUST UNITED AC 2012; 196:743-56. [PMID: 22431751 PMCID: PMC3308694 DOI: 10.1083/jcb.201112017] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
During mitosis in budding yeast, cortically anchored dynein generates pulling forces on astral microtubules to position the mitotic spindle across the mother-bud neck. The attachment molecule Num1 is required for dynein anchoring at the cell membrane, but how Num1 assembles into stationary cortical patches and interacts with dynein is unknown. We show that an N-terminal Bin/Amphiphysin/Rvs (BAR)-like domain in Num1 mediates the assembly of morphologically distinct patches and its interaction with dynein for spindle translocation into the bud. We name this domain patch assembly domain (PA; residues 1-303), as it was both necessary and sufficient for the formation of functional dynein-anchoring patches when it was attached to a pleckstrin homology domain or a CAAX motif. Distinct point mutations targeting the predicted BAR-like PA domain differentially disrupted patch assembly, dynein anchoring, and mitochondrial attachment functions of Num1. We also show that the PA domain is an elongated dimer and discuss the mechanism by which it drives patch assembly.
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Affiliation(s)
- Xianying Tang
- Biology Department, University of Massachusetts Amherst, Amherst, MA 01003, USA
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26
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Mimori-Kiyosue Y. Shaping microtubules into diverse patterns: molecular connections for setting up both ends. Cytoskeleton (Hoboken) 2011; 68:603-18. [PMID: 22021191 DOI: 10.1002/cm.20540] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Revised: 09/17/2011] [Accepted: 10/04/2011] [Indexed: 12/11/2022]
Abstract
Microtubules serve as rails for intracellular trafficking and their appropriate organization is critical for the generation of cell polarity, which is a foundation of cell differentiation, tissue morphogenesis, ontogenesis and the maintenance of homeostasis. The microtubule array is not just a static railway network; it undergoes repeated collapse and reassembly in diverse patterns during cell morphogenesis. In the last decade much progress has been made toward understanding the molecular mechanisms governing complex microtubule patterning. This review first revisits the basic principle of microtubule dynamics, and then provides an overview of how microtubules are arranged in highly shaped and functional patterns in cells changing their morphology by factors controlling the fate of microtubule ends.
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Affiliation(s)
- Yuko Mimori-Kiyosue
- Optical Image Analysis Unit, RIKEN Center for Developmental Biology, Kobe Institute, Kobe, Hyogo, Japan.
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27
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Fujita I, Yamashita A, Yamamoto M. Contribution of dynein light intermediate and intermediate chains to subcellular localization of the dynein-dynactin motor complex in Schizosaccharomyces pombe. Genes Cells 2010; 15:359-72. [PMID: 20298435 DOI: 10.1111/j.1365-2443.2010.01386.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
In fission yeast Schizosaccharomyces pombe, cytoplasmic dynein drives oscillatory nuclear movement during meiotic prophase, which may facilitate pairing of homologous chromosomes. Here, we report the identification of a dynein light intermediate chain (LIC) in fission yeast, termed Dli1p, and show that Dli1p and dynein intermediate chain (IC) Dic1p are essential for the appropriate subcellular localization and proper function of dynein during meiotic prophase. Expression of both the dli1 and dic1 genes was observed only in cells undergoing meiosis. Dli1p interacted and colocalized with dynein heavy chain Dhc1p. The subcellular localization of Dli1p was dependent on Dhc1p, and vice versa. The Dhc1p-Dli1p subcomplex could localize to the spindle pole body (SPB) with no aid of Dic1p and dynactin subunit Ssm4p, but its localization to microtubules was dependent on these two proteins. Dic1p localized to microtubules depending on Ssm4p, but not on Dhc1p and Dli1p. Its localization to the SPB, however, was dependent on Dhc1p and Dli1p. Localization of Ssm4p to the SPB was largely dependent on Dhc1p, Dli1p and Dic1p. Thus, Dli1p and Dic1p contribute differently in localizing the dynein-dynactin motor complex to organelles, providing novel insight into the in vivo function of dynein subunits in fission yeast.
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Affiliation(s)
- Ikumi Fujita
- Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Tokyo 113-0033, Japan
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28
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Tolić-Nørrelykke IM. Force and length regulation in the microtubule cytoskeleton: lessons from fission yeast. Curr Opin Cell Biol 2010; 22:21-8. [DOI: 10.1016/j.ceb.2009.12.011] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 12/01/2009] [Accepted: 12/15/2009] [Indexed: 01/12/2023]
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29
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Koszul R, Kleckner N. Dynamic chromosome movements during meiosis: a way to eliminate unwanted connections? Trends Cell Biol 2009; 19:716-24. [PMID: 19854056 DOI: 10.1016/j.tcb.2009.09.007] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2009] [Revised: 09/15/2009] [Accepted: 09/22/2009] [Indexed: 01/14/2023]
Abstract
Dramatic chromosome motion is a characteristic of mid-prophase of meiosis that is observed across broadly divergent eukaryotic phyla. Although the specific mechanisms underlying chromosome motions vary among organisms studied to date, the outcome is similar in all cases: vigorous back-and-forth movement (as fast as approximately 1mum/sec for budding yeast), led by chromosome ends (or near-end regions), and directed by cytoskeletal components via direct association through the nuclear envelope. The exact role(s) of these movements remains unknown, although an idea gaining currency is that movement serves as a stringency factor, eliminating unwanted inter-chromosomal associations or entanglements that have arisen as part of the homolog pairing process and, potentially, unwanted associations of chromatin with the nuclear envelope. Turbulent chromosome movements observed during bipolar orientation of chromosomes for segregation could also serve similar roles during mitosis. Recent advances shed light on the contribution of protein complexes involved in the meiotic movements in chromosome dynamics during the mitotic program.
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Affiliation(s)
- Romain Koszul
- CNRS URA2171, Institut Pasteur, Unité de Génétique Moléculaire des Levures, 25 rue du Dr. Roux, 75015 Paris, France
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Moore JK, Stuchell-Brereton MD, Cooper JA. Function of dynein in budding yeast: mitotic spindle positioning in a polarized cell. ACTA ACUST UNITED AC 2009; 66:546-55. [PMID: 19402153 DOI: 10.1002/cm.20364] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Cytoplasmic dynein is a microtubule motor that powers minus-end-directed motility in a variety of biological settings. The budding yeast, Saccharomyces cerevisiae, has been a useful system for the study of dynein, due to its molecular genetics and cell biology capabilities, coupled with the conservation of dynein-pathway proteins. In this review we discuss how budding yeast use dynein to manipulate the position of the mitotic spindle and the nucleus during cell division, using cytoplasmic microtubules, and we describe our current understanding of the genes required for dynein function. Cell Motil. Cytoskeleton 2009. (c) 2009 Wiley-Liss, Inc.
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Affiliation(s)
- Jeffrey K Moore
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA.
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31
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Vogel SK, Pavin N, Maghelli N, Jülicher F, Tolić-Nørrelykke IM. Self-organization of dynein motors generates meiotic nuclear oscillations. PLoS Biol 2009; 7:e1000087. [PMID: 19385717 PMCID: PMC2671556 DOI: 10.1371/journal.pbio.1000087] [Citation(s) in RCA: 107] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 03/04/2009] [Indexed: 11/19/2022] Open
Abstract
Meiotic nuclear oscillations in the fission yeast Schizosaccharomyces pombe are crucial for proper chromosome pairing and recombination. We report a mechanism of these oscillations on the basis of collective behavior of dynein motors linking the cell cortex and dynamic microtubules that extend from the spindle pole body in opposite directions. By combining quantitative live cell imaging and laser ablation with a theoretical description, we show that dynein dynamically redistributes in the cell in response to load forces, resulting in more dynein attached to the leading than to the trailing microtubules. The redistribution of motors introduces an asymmetry of motor forces pulling in opposite directions, leading to the generation of oscillations. Our work provides the first direct in vivo observation of self-organized dynamic dynein distributions, which, owing to the intrinsic motor properties, generate regular large-scale movements in the cell.
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Affiliation(s)
- Sven K Vogel
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Nenad Pavin
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
- Department of Physics, Faculty of Science, University of Zagreb, Zagreb, Croatia
| | - Nicola Maghelli
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Frank Jülicher
- Max Planck Institute for the Physics of Complex Systems, Dresden, Germany
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32
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Fischer R, Zekert N, Takeshita N. Polarized growth in fungi--interplay between the cytoskeleton, positional markers and membrane domains. Mol Microbiol 2008; 68:813-26. [PMID: 18399939 DOI: 10.1111/j.1365-2958.2008.06193.x] [Citation(s) in RCA: 146] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
One kind of the most extremely polarized cells in nature are the indefinitely growing hyphae of filamentous fungi. A continuous flow of secretion vesicles from the hyphal cell body to the growing hyphal tip is essential for cell wall and membrane extension. Because microtubules (MT) and actin, together with their corresponding motor proteins, are involved in the process, the arrangement of the cytoskeleton is a crucial step to establish and maintain polarity. In Saccharomyces cerevisiae and Schizosaccharomyces pombe, actin-mediated vesicle transportation is sufficient for polar cell extension, but in S. pombe, MTs are in addition required for the establishment of polarity. The MT cytoskeleton delivers the so-called cell-end marker proteins to the cell pole, which in turn polarize the actin cytoskeleton. Latest results suggest that this scenario may principally be conserved from S. pombe to filamentous fungi. In addition, in filamentous fungi, MTs could provide the tracks for long-distance vesicle movement. In this review, we will compare the interaction of the MT and the actin cytoskeleton and their relation to the cortex between yeasts and filamentous fungi. In addition, we will discuss the role of sterol-rich membrane domains in combination with cell-end marker proteins for polarity establishment.
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Affiliation(s)
- Reinhard Fischer
- Department of Applied Microbiology, University of Karlsruhe, Hertzstrasse 16, D-76187 Karlsruhe, Germany
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Cromie G, Smith GR. Meiotic Recombination in Schizosaccharomyces pombe: A Paradigm for Genetic and Molecular Analysis. GENOME DYNAMICS AND STABILITY 2008; 3:195. [PMID: 20157622 DOI: 10.1007/7050_2007_025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
The fission yeast Schizosaccharomyces pombe is especially well-suited for both genetic and biochemical analysis of meiotic recombination. Recent studies have revealed ~50 gene products and two DNA intermediates central to recombination, which we place into a pathway from parental to recombinant DNA. We divide recombination into three stages - chromosome alignment accompanying nuclear "horsetail" movement, formation of DNA breaks, and repair of those breaks - and we discuss the roles of the identified gene products and DNA intermediates in these stages. Although some aspects of recombination are similar to those in the distantly related budding yeast Saccharomyces cerevisiae, other aspects are distinctly different. In particular, many proteins required for recombination in one species have no clear ortholog in the other, and the roles of identified orthologs in regulating recombination often differ. Furthermore, in S. pombe the dominant joint DNA molecule intermediates contain single Holliday junctions, and intersister joint molecules are more frequent than interhomolog types, whereas in S. cerevisiae interhomolog double Holliday junctions predominate. We speculate that meiotic recombination in other organisms shares features of each of these yeasts.
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Affiliation(s)
- Gareth Cromie
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, U. S. A
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Tomita K, Cooper JP. The telomere bouquet controls the meiotic spindle. Cell 2007; 130:113-26. [PMID: 17632059 DOI: 10.1016/j.cell.2007.05.024] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Revised: 03/07/2007] [Accepted: 05/03/2007] [Indexed: 10/23/2022]
Abstract
Bouquet formation, in which telomeres gather to a small region of the nuclear membrane in early meiosis, has been observed in diverse eukaryotes, but the function of the bouquet has remained a mystery. Here, we demonstrate that the telomere bouquet plays a crucial role in controlling the behavior of the fission yeast microtubule-organizing center (known as the spindle pole body or SPB) and the meiotic spindle. Using mutations that specifically disrupt the bouquet, we analyze chromosome, SPB, and spindle dynamics throughout meiosis. If the bouquet fails to form, the SPB becomes fragmented at meiosis I, leading to monopolar, multiple, and mislocalized spindles. Correct SPB and spindle behavior require not only the SPB recruitment of telomere proteins but also that the proteins are properly bound to telomeric DNA. This discovery illuminates an unanticipated level of communication between chromosomes and the spindle apparatus that may be widely conserved among eukaryotes.
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Affiliation(s)
- Kazunori Tomita
- Telomere Biology Laboratory, Cancer Research UK, London WC2A 3PX, UK
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Ligon LA, Holzbaur ELF. Microtubules Tethered at Epithelial Cell Junctions by Dynein Facilitate Efficient Junction Assembly. Traffic 2007; 8:808-19. [PMID: 17550375 DOI: 10.1111/j.1600-0854.2007.00574.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Efficient remodeling of cell-cell adhesions is critical during development and morphogenesis. Junctional components must be specifically and rapidly transported to sites of junction assembly. In this study, we show a mechanism by which this targeted trafficking may occur. Microtubules target epithelial adherens junctions, and the number of microtubules both projecting to and tethered at sites of contact is increased during junction assembly, consistent with an increased need for new material at the nascent junction. Cytoplasmic dynein is localized to sites of cell-cell contact, and microtubules project to dynein patches where they become tethered. Microinjection of anti-dynein antibodies disrupts the tethering of microtubules, showing that the motor anchors them. Furthermore, disruption of dynein inhibits junction formation. Immunocytochemistry with antibodies to p120 catenin support the hypothesis that tethered microtubules serve as tracks for delivery of new components to forming junctions, suggesting a model in which material is targeted for delivery to sites of need through microtubules tethered by dynein.
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Affiliation(s)
- Lee A Ligon
- Department of Biology and the Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA
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Ohtaka A, Saito TT, Okuzaki D, Nojima H. Meiosis specific coiled-coil proteins in Shizosaccharomyces pombe. Cell Div 2007; 2:14. [PMID: 17509158 PMCID: PMC1885245 DOI: 10.1186/1747-1028-2-14] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2007] [Accepted: 05/18/2007] [Indexed: 01/07/2023] Open
Abstract
Many meiosis-specific proteins in Schizosaccharomyces pombe contain coiled-coil motifs which play essential roles for meiotic progression. For example, the coiled-coil motifs present in Meu13 and Mcp7 are required for their function as a putative recombinase cofactor complex during meiotic recombination. Mcp6/Hrs1 and Mcp5/Num1 control horsetail chromosome movement by astral microtubule organization and anchoring dynein respectively. Dhc1 and Ssm4 are also required for horsetail chromosome movement. It is clear from these examples that the coiled-coil motif in these proteins plays an important role during the progression of cells through meiosis. However, there are still many unanswered questions on how these proteins operate. In this paper, we briefly review recent studies on the meiotic coiled-coil proteins in Sz. pombe.
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Affiliation(s)
- Ayami Ohtaka
- Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Takamune T Saito
- Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
- Department of Genetics, Harvard Medical School 77 Avenue Louis Pasteur, New Research Building, Room 334, Boston, MA 02115, USA
| | - Daisuke Okuzaki
- Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Hiroshi Nojima
- Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan
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Ohtaka A, Okuzaki D, Saito TT, Nojima H. Mcp4, a meiotic coiled-coil protein, plays a role in F-actin positioning during Schizosaccharomyces pombe meiosis. EUKARYOTIC CELL 2007; 6:971-83. [PMID: 17435009 PMCID: PMC1951525 DOI: 10.1128/ec.00016-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Some meiosis-specific proteins of Schizosaccharomyces pombe harbor coiled-coil motifs and play essential roles in meiotic progression. Here we describe Mcp4, a novel meiosis-specific protein whose expression is abruptly induced at the horsetail phase and which remains expressed until sporulation is finished. Fluorescence microscopic analysis revealed that Mcp4 alters its subcellular localization during meiosis in a manner that partially resembles the movement of F-actin during meiosis. Mcp4 and F-actin never colocalize; rather, they are located in a side-by-side manner. When forespore membrane formation begins at metaphase II, the Mcp4 signals assemble at the lagging face of the dividing nuclei. At this stage, they are sandwiched between F-actin and the nucleus. Mcp4, in turn, appears to sandwich F-actin with Meu14. In mcp4Delta cells at anaphase II, the F-actin, which is normally dumbbell-shaped, adopts an abnormal balloon shape. Spores of mcp4Delta cells were sensitive to NaCl, although their shape and viability were normal. Taken together, we conclude that Mcp4 plays a role in the accurate positioning of F-actin during S. pombe meiosis.
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Affiliation(s)
- Ayami Ohtaka
- Department of Molecular Genetics, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita City, Osaka 565-0871, Japan
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Current awareness on yeast. Yeast 2007. [DOI: 10.1002/yea.1324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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