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MYO6 is targeted by Salmonella virulence effectors to trigger PI3-kinase signaling and pathogen invasion into host cells. Proc Natl Acad Sci U S A 2017; 114:3915-3920. [PMID: 28348208 DOI: 10.1073/pnas.1616418114] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To establish infections, Salmonella injects virulence effectors that hijack the host actin cytoskeleton and phosphoinositide signaling to drive pathogen invasion. How effectors reprogram the cytoskeleton network remains unclear. By reconstituting the activities of the Salmonella effector SopE, we recapitulated Rho GTPase-driven actin polymerization at model phospholipid membrane bilayers in cell-free extracts and identified the network of Rho-recruited cytoskeleton proteins. Knockdown of network components revealed a key role for myosin VI (MYO6) in Salmonella invasion. SopE triggered MYO6 localization to invasion foci, and SopE-mediated activation of PAK recruited MYO6 to actin-rich membranes. We show that the virulence effector SopB requires MYO6 to regulate the localization of PIP3 and PI(3)P phosphoinositides and Akt activation. SopE and SopB target MYO6 to coordinate phosphoinositide production at invasion foci, facilitating the recruitment of cytoskeleton adaptor proteins to mediate pathogen uptake.
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Decarreau J, Wagenbach M, Lynch E, Halpern AR, Vaughan JC, Kollman J, Wordeman L. The tetrameric kinesin Kif25 suppresses pre-mitotic centrosome separation to establish proper spindle orientation. Nat Cell Biol 2017; 19:384-390. [PMID: 28263957 PMCID: PMC5376238 DOI: 10.1038/ncb3486] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Accepted: 02/03/2017] [Indexed: 12/17/2022]
Abstract
Microtubules tether centrosomes together during interphase. How this is accomplished and what benefit it provides to the cell is not known. We have identified a bipolar, minus-end-directed kinesin, Kif25, that suppresses centrosome separation. Kif25 is required to prevent premature centrosome separation during interphase. We show that premature centrosome separation leads to microtubule-dependent nuclear translocation, culminating in eccentric nuclear positioning that disrupts the cortical spindle positioning machinery. The activity of Kif25 during interphase is required to maintain a centred nucleus to ensure the spindle is stably oriented at the onset of mitosis.
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Affiliation(s)
- Justin Decarreau
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA
| | - Michael Wagenbach
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA
| | - Eric Lynch
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Aaron R Halpern
- Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Joshua C Vaughan
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA.,Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
| | - Justin Kollman
- Department of Biochemistry, University of Washington, Seattle, Washington 98195, USA
| | - Linda Wordeman
- Department of Physiology and Biophysics, University of Washington, Seattle, Washington 98195, USA
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53
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Mishima M. Preparation of centralspindlin as an active heterotetramer of kinesin and GTPase activating protein subunits for in vitro structural and functional assays. Methods Cell Biol 2017; 137:371-385. [DOI: 10.1016/bs.mcb.2016.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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54
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E2F-2 Promotes Nuclear Condensation and Enucleation of Terminally Differentiated Erythroblasts. Mol Cell Biol 2016; 37:MCB.00274-16. [PMID: 27795297 PMCID: PMC5192079 DOI: 10.1128/mcb.00274-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 10/04/2016] [Indexed: 12/31/2022] Open
Abstract
E2F-2 is a retinoblastoma (Rb)-regulated transcription factor induced during terminal erythroid maturation. Cyclin E-mediated Rb hyperphosphorylation induces E2F transcriptional activator functions. We previously reported that deregulated cyclin E activity causes defective terminal maturation of nucleated erythroblasts in vivo Here, we found that these defects are normalized by E2F-2 deletion; however, anemia in mice with deregulated cyclin E is not improved by E2F-2-loss, which itself causes reduced peripheral red blood cell (RBC) counts without altering relative abundances of erythroblast subpopulations. To determine how E2F-2 regulates RBC production, we comprehensively studied erythropoiesis using knockout mice and hematopoietic progenitors. We found that efficient stress erythropoiesis in vivo requires E2F-2, and we also identified an unappreciated role for E2F-2 in erythroblast enucleation. In particular, E2F-2 deletion impairs nuclear condensation, a morphological feature of maturing erythroblasts. Transcriptome profiling of E2F-2-null, mature erythroblasts demonstrated widespread changes in gene expression. Notably, we identified citron Rho-interacting kinase (CRIK), which has known functions in mitosis and cytokinesis, as induced in erythroblasts in an E2F-2-dependent manner, and we found that CRIK activity promotes efficient erythroblast enucleation and nuclear condensation. Together, our data reveal novel, lineage-specific functions for E2F-2 and suggest that some mitotic kinases have specialized roles supporting enucleation of maturing erythroblasts.
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55
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Luján P, Varsano G, Rubio T, Hennrich ML, Sachsenheimer T, Gálvez-Santisteban M, Martín-Belmonte F, Gavin AC, Brügger B, Köhn M. PRL-3 disrupts epithelial architecture by altering the post-mitotic midbody position. J Cell Sci 2016; 129:4130-4142. [PMID: 27656108 PMCID: PMC5117205 DOI: 10.1242/jcs.190215] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 09/16/2016] [Indexed: 12/20/2022] Open
Abstract
Disruption of epithelial architecture is a fundamental event during epithelial tumorigenesis. We show that the expression of the cancer-promoting phosphatase PRL-3 (PTP4A3), which is overexpressed in several epithelial cancers, in polarized epithelial MDCK and Caco2 cells leads to invasion and the formation of multiple ectopic, fully polarized lumens in cysts. Both processes disrupt epithelial architecture and are hallmarks of cancer. The pathological relevance of these findings is supported by the knockdown of endogenous PRL-3 in MCF-7 breast cancer cells grown in three-dimensional branched structures, showing the rescue from multiple-lumen- to single-lumen-containing branch ends. Mechanistically, it has been previously shown that ectopic lumens can arise from midbodies that have been mislocalized through the loss of mitotic spindle orientation or through the loss of asymmetric abscission. Here, we show that PRL-3 triggers ectopic lumen formation through midbody mispositioning without altering the spindle orientation or asymmetric abscission, instead, PRL-3 accelerates cytokinesis, suggesting that this process is an alternative new mechanism for ectopic lumen formation in MDCK cysts. The disruption of epithelial architecture by PRL-3 revealed here is a newly recognized mechanism for PRL-3-promoted cancer progression.
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Affiliation(s)
- Pablo Luján
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg 69117, Germany
| | - Giulia Varsano
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg 69117, Germany
| | - Teresa Rubio
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg 69117, Germany
| | - Marco L Hennrich
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg 69117, Germany
| | - Timo Sachsenheimer
- Heidelberg University Biochemistry Center, University of Heidelberg, Heidelberg 69120, Germany
| | - Manuel Gálvez-Santisteban
- Department of Development and Differentiation, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Madrid 28049, Spain
| | - Fernando Martín-Belmonte
- Department of Development and Differentiation, Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas (CSIC), Madrid 28049, Spain
| | - Anne-Claude Gavin
- European Molecular Biology Laboratory, Structural and Computational Biology Unit, Heidelberg 69117, Germany
| | - Britta Brügger
- Heidelberg University Biochemistry Center, University of Heidelberg, Heidelberg 69120, Germany
| | - Maja Köhn
- European Molecular Biology Laboratory, Genome Biology Unit, Heidelberg 69117, Germany
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56
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Gai M, Bianchi FT, Vagnoni C, Vernì F, Bonaccorsi S, Pasquero S, Berto GE, Sgrò F, Chiotto AM, Annaratone L, Sapino A, Bergo A, Landsberger N, Bond J, Huttner WB, Di Cunto F. ASPM and CITK regulate spindle orientation by affecting the dynamics of astral microtubules. EMBO Rep 2016; 17:1396-1409. [PMID: 27562601 DOI: 10.15252/embr.201541823] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Accepted: 07/26/2016] [Indexed: 11/09/2022] Open
Abstract
Correct orientation of cell division is considered an important factor for the achievement of normal brain size, as mutations in genes that affect this process are among the leading causes of microcephaly. Abnormal spindle orientation is associated with reduction of the neuronal progenitor symmetric divisions, premature cell cycle exit, and reduced neurogenesis. This mechanism has been involved in microcephaly resulting from mutation of ASPM, the most frequently affected gene in autosomal recessive human primary microcephaly (MCPH), but it is presently unknown how ASPM regulates spindle orientation. In this report, we show that ASPM may control spindle positioning by interacting with citron kinase (CITK), a protein whose loss is also responsible for severe microcephaly in mammals. We show that the absence of CITK leads to abnormal spindle orientation in mammals and insects. In mouse cortical development, this phenotype correlates with increased production of basal progenitors. ASPM is required to recruit CITK at the spindle, and CITK overexpression rescues ASPM phenotype. ASPM and CITK affect the organization of astral microtubules (MT), and low doses of MT-stabilizing drug revert the spindle orientation phenotype produced by their knockdown. Finally, CITK regulates both astral-MT nucleation and stability. Our results provide a functional link between two established microcephaly proteins.
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Affiliation(s)
- Marta Gai
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Federico T Bianchi
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Cristiana Vagnoni
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Fiammetta Vernì
- Department of Biology and Biotechnologies "C. Darwin", Sapienza, Università di Roma, Rome, Italy
| | - Silvia Bonaccorsi
- Department of Biology and Biotechnologies "C. Darwin", Sapienza, Università di Roma, Rome, Italy
| | - Selina Pasquero
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Gaia E Berto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Francesco Sgrò
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Alessandra Ma Chiotto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Laura Annaratone
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Anna Sapino
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Anna Bergo
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Nicoletta Landsberger
- San Raffaele Rett Research Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Jacqueline Bond
- Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Leeds, UK
| | - Wieland B Huttner
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - Ferdinando Di Cunto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
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57
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Liu Q, Liu F, Yu KL, Tas R, Grigoriev I, Remmelzwaal S, Serra-Marques A, Kapitein LC, Heck AJR, Akhmanova A. MICAL3 Flavoprotein Monooxygenase Forms a Complex with Centralspindlin and Regulates Cytokinesis. J Biol Chem 2016; 291:20617-29. [PMID: 27528609 DOI: 10.1074/jbc.m116.748186] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Indexed: 12/18/2022] Open
Abstract
During cytokinesis, the antiparallel array of microtubules forming the central spindle organizes the midbody, a structure that anchors the ingressed cleavage furrow and guides the assembly of abscission machinery. Here, we identified a role for the flavoprotein monooxygenase MICAL3, an actin disassembly factor, in organizing midbody-associated protein complexes. By combining cell biological assays with cross-linking mass spectrometry, we show that MICAL3 is recruited to the central spindle and the midbody through a direct interaction with the centralspindlin component MKLP1. Knock-out of MICAL3 leads to an increased frequency of cytokinetic failure and a delayed abscission. In a mechanism independent of its enzymatic activity, MICAL3 targets the adaptor protein ELKS and Rab8A-positive vesicles to the midbody, and the depletion of ELKS and Rab8A also leads to cytokinesis defects. We propose that MICAL3 acts as a midbody-associated scaffold for vesicle targeting, which promotes maturation of the intercellular bridge and abscission.
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Affiliation(s)
- Qingyang Liu
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Fan Liu
- the Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Ka Lou Yu
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Roderick Tas
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Ilya Grigoriev
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Sanne Remmelzwaal
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Andrea Serra-Marques
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Lukas C Kapitein
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
| | - Albert J R Heck
- the Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Anna Akhmanova
- From the Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH Utrecht and
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58
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Olenick MA, Tokito M, Boczkowska M, Dominguez R, Holzbaur ELF. Hook Adaptors Induce Unidirectional Processive Motility by Enhancing the Dynein-Dynactin Interaction. J Biol Chem 2016; 291:18239-51. [PMID: 27365401 DOI: 10.1074/jbc.m116.738211] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Indexed: 11/06/2022] Open
Abstract
Cytoplasmic dynein drives the majority of minus end-directed vesicular and organelle motility in the cell. However, it remains unclear how dynein is spatially and temporally regulated given the variety of cargo that must be properly localized to maintain cellular function. Recent work has suggested that adaptor proteins provide a mechanism for cargo-specific regulation of motors. Of particular interest, studies in fungal systems have implicated Hook proteins in the regulation of microtubule motors. Here we investigate the role of mammalian Hook proteins, Hook1 and Hook3, as potential motor adaptors. We used optogenetic approaches to specifically recruit Hook proteins to organelles and observed rapid transport of peroxisomes to the perinuclear region of the cell. This rapid and efficient translocation of peroxisomes to microtubule minus ends indicates that mammalian Hook proteins activate dynein rather than kinesin motors. Biochemical studies indicate that Hook proteins interact with both dynein and dynactin, stabilizing the formation of a supramolecular complex. Complex formation requires the N-terminal domain of Hook proteins, which resembles the calponin-homology domain of end-binding (EB) proteins but cannot bind directly to microtubules. Single-molecule motility assays using total internal reflection fluorescence microscopy indicate that both Hook1 and Hook3 effectively activate cytoplasmic dynein, inducing longer run lengths and higher velocities than the previously characterized dynein activator bicaudal D2 (BICD2). Together, these results suggest that dynein adaptors can differentially regulate dynein to allow for organelle-specific tuning of the motor for precise intracellular trafficking.
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Affiliation(s)
- Mara A Olenick
- From the Department of Physiology and Pennsylvania Muscle Institute and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Mariko Tokito
- From the Department of Physiology and Pennsylvania Muscle Institute and
| | | | - Roberto Dominguez
- From the Department of Physiology and Pennsylvania Muscle Institute and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
| | - Erika L F Holzbaur
- From the Department of Physiology and Pennsylvania Muscle Institute and Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, Pennsylvania 19104
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59
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Abstract
The myosin holoenzyme is a multimeric protein complex consisting of heavy chains and light chains. Myosin light chains are calmodulin family members which are crucially involved in the mechanoenzymatic function of the myosin holoenzyme. This review examines the diversity of light chains within the myosin superfamily, discusses interactions between the light chain and the myosin heavy chain as well as regulatory and structural functions of the light chain as a subunit of the myosin holoenzyme. It covers aspects of the myosin light chain in the localization of the myosin holoenzyme, protein-protein interactions and light chain binding to non-myosin binding partners. Finally, this review challenges the dogma that myosin regulatory and essential light chain exclusively associate with conventional myosin heavy chains while unconventional myosin heavy chains usually associate with calmodulin.
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Affiliation(s)
- Sarah M Heissler
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
| | - James R Sellers
- a Laboratory of Molecular Physiology; National Heart, Lung, and Blood Institute; National Institutes of Health ; Bethesda , MD USA
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60
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Abstract
Protein-protein interactions (PPIs) underlie most, if not all, cellular functions. The comprehensive mapping of these complex networks of stable and transient associations thus remains a key goal, both for systems biology-based initiatives (where it can be combined with other 'omics' data to gain a better understanding of functional pathways and networks) and for focused biological studies. Despite the significant challenges of such an undertaking, major strides have been made over the past few years. They include improvements in the computation prediction of PPIs and the literature curation of low-throughput studies of specific protein complexes, but also an increase in the deposition of high-quality data from non-biased high-throughput experimental PPI mapping strategies into publicly available databases.
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Affiliation(s)
- Virja Mehta
- Department of Cellular and Molecular Medicine, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine, Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, ON, Canada
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61
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Heissler SM, Sellers JR. Four things to know about myosin light chains as reporters for non-muscle myosin-2 dynamics in live cells. Cytoskeleton (Hoboken) 2016; 72:65-70. [PMID: 25712372 DOI: 10.1002/cm.21212] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 12/19/2014] [Accepted: 02/03/2015] [Indexed: 11/07/2022]
Abstract
The interplay between non-muscle myosins-2 and filamentous actin results in cytoplasmic contractility which is essential for eukaryotic life. Concomitantly, there is tremendous interest in elucidating the physiological function and temporal localization of non-muscle myosin-2 in cells. A commonly used method to study the function and localization of non-muscle myosin-2 is to overexpress a fluorescent protein (FP)-tagged version of the regulatory light chain (RLC) which binds to the myosin-2 heavy chain by mass action. Caveats about this approach include findings from recent studies indicating that the RLC does not bind exclusively to the non-muscle myosin-2 heavy chain. Rather, it can also associate with the myosin heavy chains of several other classes as well as other targets than myosin. In addition, the presence of the FP moiety may compromise myosin's enzymatic and mechanical performance. This and other factors to be discussed in this commentary raise questions about the possible complications in using FP-RLC as a marker for the dynamic localization and regulatory aspects of non-muscle myosin-2 motor functions in cell biological experiments.
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Affiliation(s)
- Sarah M Heissler
- Laboratory of Molecular Physiology, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland
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62
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Abstract
At first glance, mitosis in plants looks quite different from that in animals. In fact, terrestrial plants have lost the centrosome during evolution, and the mitotic spindle is assembled independently of a strong microtubule organizing center. The phragmoplast is a plant-specific mitotic apparatus formed after anaphase, which expands centrifugally towards the cell cortex. However, the extent to which plant mitosis differs from that of animals at the level of the protein repertoire is uncertain, largely because of the difficulty in the identification and in vivo characterization of mitotic genes of plants. Here, we discuss protocols for mitosis imaging that can be combined with endogenous green fluorescent protein (GFP) tagging or conditional RNA interference (RNAi) in the moss Physcomitrella patens, which is an emergent model plant for cell and developmental biology. This system has potential for use in the high-throughput study of mitosis and other intracellular processes, as is being done with various animal cell lines.
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63
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Sgrò F, Bianchi FT, Falcone M, Pallavicini G, Gai M, Chiotto AMA, Berto GE, Turco E, Chang YJ, Huttner WB, Di Cunto F. Tissue-specific control of midbody microtubule stability by Citron kinase through modulation of TUBB3 phosphorylation. Cell Death Differ 2015; 23:801-13. [PMID: 26586574 DOI: 10.1038/cdd.2015.142] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Revised: 09/13/2015] [Accepted: 09/29/2015] [Indexed: 01/02/2023] Open
Abstract
Cytokinesis, the physical separation of daughter cells at the end of cell cycle, is commonly considered a highly stereotyped phenomenon. However, in some specialized cells this process may involve specific molecular events that are still largely unknown. In mammals, loss of Citron-kinase (CIT-K) leads to massive cytokinesis failure and apoptosis only in neuronal progenitors and in male germ cells, resulting in severe microcephaly and testicular hypoplasia, but the reasons for this specificity are unknown. In this report we show that CIT-K modulates the stability of midbody microtubules and that the expression of tubulin β-III (TUBB3) is crucial for this phenotype. We observed that TUBB3 is expressed in proliferating CNS progenitors, with a pattern correlating with the susceptibility to CIT-K loss. More importantly, depletion of TUBB3 in CIT-K-dependent cells makes them resistant to CIT-K loss, whereas TUBB3 overexpression increases their sensitivity to CIT-K knockdown. The loss of CIT-K leads to a strong decrease in the phosphorylation of S444 on TUBB3, a post-translational modification associated with microtubule stabilization. CIT-K may promote this event by interacting with TUBB3 and by recruiting at the midbody casein kinase-2α (CK2α) that has previously been reported to phosphorylate the S444 residue. Indeed, CK2α is lost from the midbody in CIT-K-depleted cells. Moreover, expression of the nonphosphorylatable TUBB3 mutant S444A induces cytokinesis failure, whereas expression of the phospho-mimetic mutant S444D rescues the cytokinesis failure induced by both CIT-K and CK2α loss. Altogether, our findings reveal that expression of relatively low levels of TUBB3 in mitotic cells can be detrimental for their cytokinesis and underscore the importance of CIT-K in counteracting this event.
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Affiliation(s)
- F Sgrò
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - F T Bianchi
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - M Falcone
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - G Pallavicini
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - M Gai
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - A M A Chiotto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - G E Berto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - E Turco
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - Y J Chang
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - W B Huttner
- Max-Planck Institute of Molecular Cell Biology and Genetics, Dresden, Germany
| | - F Di Cunto
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy.,Neuroscience Institute of Turin, Turin, Italy
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64
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Hein MY, Hubner NC, Poser I, Cox J, Nagaraj N, Toyoda Y, Gak IA, Weisswange I, Mansfeld J, Buchholz F, Hyman AA, Mann M. A human interactome in three quantitative dimensions organized by stoichiometries and abundances. Cell 2015; 163:712-23. [PMID: 26496610 DOI: 10.1016/j.cell.2015.09.053] [Citation(s) in RCA: 895] [Impact Index Per Article: 99.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2015] [Revised: 07/06/2015] [Accepted: 09/17/2015] [Indexed: 02/06/2023]
Abstract
The organization of a cell emerges from the interactions in protein networks. The interactome is critically dependent on the strengths of interactions and the cellular abundances of the connected proteins, both of which span orders of magnitude. However, these aspects have not yet been analyzed globally. Here, we have generated a library of HeLa cell lines expressing 1,125 GFP-tagged proteins under near-endogenous control, which we used as input for a next-generation interaction survey. Using quantitative proteomics, we detect specific interactions, estimate interaction stoichiometries, and measure cellular abundances of interacting proteins. These three quantitative dimensions reveal that the protein network is dominated by weak, substoichiometric interactions that play a pivotal role in defining network topology. The minority of stable complexes can be identified by their unique stoichiometry signature. This study provides a rich interaction dataset connecting thousands of proteins and introduces a framework for quantitative network analysis.
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Affiliation(s)
- Marco Y Hein
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Nina C Hubner
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Ina Poser
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Jürgen Cox
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | | | - Yusuke Toyoda
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Igor A Gak
- Cell Cycle, Biotechnology Center, TU Dresden, 01307 Dresden, Germany
| | - Ina Weisswange
- Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany; Eupheria Biotech GmbH, 01307 Dresden, Germany
| | - Jörg Mansfeld
- Cell Cycle, Biotechnology Center, TU Dresden, 01307 Dresden, Germany
| | - Frank Buchholz
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany; Medical Systems Biology, UCC, Medical Faculty Carl Gustav Carus, TU Dresden, 01307 Dresden, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany.
| | - Matthias Mann
- Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
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65
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Hasse S, Hyman AA, Sarov M. TransgeneOmics--A transgenic platform for protein localization based function exploration. Methods 2015; 96:69-74. [PMID: 26475212 DOI: 10.1016/j.ymeth.2015.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Revised: 10/09/2015] [Accepted: 10/10/2015] [Indexed: 12/17/2022] Open
Abstract
The localization of a protein is intrinsically linked to its role in the structural and functional organization of the cell. Advances in transgenic technology have streamlined the use of protein localization as a function discovery tool. Here we review the use of large genomic DNA constructs such as bacterial artificial chromosomes as a transgenic platform for systematic tag-based protein function exploration.
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Affiliation(s)
- Susanne Hasse
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
| | - Anthony A Hyman
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
| | - Mihail Sarov
- Max Planck Institute of Molecular Cell Biology and Genetics Dresden, Germany
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66
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Abstract
Despite the importance of mitotic cell rounding in tissue development and cell proliferation, there remains a paucity of approaches to investigate the mechanical robustness of cell rounding. Here we introduce ion beam-sculpted microcantilevers that enable precise force-feedback-controlled confinement of single cells while characterizing their progression through mitosis. We identify three force regimes according to the cell response: small forces (∼5 nN) that accelerate mitotic progression, intermediate forces where cells resist confinement (50-100 nN), and yield forces (>100 nN) where a significant decline in cell height impinges on microtubule spindle function, thereby inhibiting mitotic progression. Yield forces are coincident with a nonlinear drop in cell height potentiated by persistent blebbing and loss of cortical F-actin homogeneity. Our results suggest that a buildup of actomyosin-dependent cortical tension and intracellular pressure precedes mechanical failure, or herniation, of the cell cortex at the yield force. Thus, we reveal how the mechanical properties of mitotic cells and their response to external forces are linked to mitotic progression under conditions of mechanical confinement.
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67
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Nek2 activation of Kif24 ensures cilium disassembly during the cell cycle. Nat Commun 2015; 6:8087. [PMID: 26290419 PMCID: PMC4545512 DOI: 10.1038/ncomms9087] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 07/16/2015] [Indexed: 01/07/2023] Open
Abstract
Many proteins are known to promote ciliogenesis, but mechanisms that promote primary cilia disassembly before mitosis are largely unknown. Here we identify a mechanism that favours cilium disassembly and maintains the disassembled state. We show that co-localization of the S/G2 phase kinase, Nek2 and Kif24 triggers Kif24 phosphorylation, inhibiting cilia formation. We show that Kif24, a microtubule depolymerizing kinesin, is phosphorylated by Nek2, which stimulates its activity and prevents the outgrowth of cilia in proliferating cells, independent of Aurora A and HDAC6. Our data also suggest that cilium assembly and disassembly are in dynamic equilibrium, but Nek2 and Kif24 can shift the balance toward disassembly. Further, Nek2 and Kif24 are overexpressed in breast cancer cells, and ablation of these proteins restores ciliation in these cells, thereby reducing proliferation. Thus, Kif24 is a physiological substrate of Nek2, which regulates cilia disassembly through a concerted mechanism involving Kif24-mediated microtubule depolymerization. Most differentiated mammalian cells assemble a primary cilium, which serves as a cellular ‘antenna' for sensing and responding to the extracellular environment. Here the authors show that Nek2-mediated phosphorylation of Kif24 further promotes the loss of primary cilia, triggered by Aurora A and HDAC6 on cell cycle re-entry.
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68
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Dumoux M, Menny A, Delacour D, Hayward RD. A Chlamydia effector recruits CEP170 to reprogram host microtubule organization. J Cell Sci 2015. [PMID: 26220855 PMCID: PMC4582400 DOI: 10.1242/jcs.169318] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The obligate intracellular bacterial pathogen Chlamydia trachomatis deploys virulence effectors to subvert host cell functions enabling its replication within a specialized membrane-bound compartment termed an inclusion. The control of the host cytoskeleton is crucial for Chlamydia uptake, inclusion biogenesis and cell exit. Here, we demonstrate how a Chlamydia effector rearranges the microtubule (MT) network by initiating organization of the MTs at the inclusion surface. We identified an inclusion-localized effector that is sufficient to interfere with MT assembly, which we named inclusion protein acting on MTs (IPAM). We established that IPAM recruits and stimulates the centrosomal protein 170 kDa (CEP170) to hijack the MT organizing functions of the host cell. We show that CEP170 is essential for chlamydial control of host MT assembly, and is required for inclusion morphogenesis and bacterial infectivity. Together, we demonstrate how a pathogen effector reprograms the host MT network to support its intracellular development.
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Affiliation(s)
- Maud Dumoux
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
| | - Anais Menny
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
| | - Delphine Delacour
- Cell Adhesion and Mechanics Group, Institut Jacques Monod, CNRS UMR7592, Université Paris Diderot, 15 rue Helene Brion, Paris 75013, France
| | - Richard D Hayward
- Institute of Structural and Molecular Biology, Birkbeck and University College London, Malet Street, London WC1E 7HX, UK
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69
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Xiong R, Rao P, Kim S, Li M, Wen X, Yuan W. Herpes Simplex Virus 1 US3 Phosphorylates Cellular KIF3A To Downregulate CD1d Expression. J Virol 2015; 89:6646-55. [PMID: 25878107 PMCID: PMC4468489 DOI: 10.1128/jvi.00214-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2015] [Accepted: 04/09/2015] [Indexed: 01/15/2023] Open
Abstract
UNLABELLED Herpes simplex virus 1 (HSV-1) causes one of the most prevalent herpesviral infections in humans and is the leading etiological agent of viral encephalitis and eye infections. Our understanding of how HSV-1 interacts with the host at the cellular and organismal levels is still limited. We and others previously reported that, upon infection, HSV-1 rapidly and efficiently downregulates CD1d cell surface expression and suppresses the function of NKT cells, a group of innate T cells with critical immunoregulatory function. The viral protein kinase US3 plays a major role in this immune evasion mechanism, and its kinase activity is required for this function. In this study, we investigated the cellular substrate(s) phosphorylated by US3 and how it mediates US3 suppression of CD1d recycling. We identified the type II kinesin motor protein KIF3A as a critical kinesin factor in the cell surface expression of CD1d. Interestingly, KIF3A is phosphorylated by US3 both in vitro and in infected cells. Mass spectrometry analysis of purified KIF3A showed that it is phosphorylated predominantly at serine 687 by US3. Ablation of this phosphorylation abolished US3-mediated downregulation of CD1d expression, suggesting that phosphorylation of KIF3A is the primary mechanism of HSV-1 suppression of CD1d expression by US3 protein. Understanding of the precise mechanism of viral modulation of CD1d expression will help to develop more efficient vaccines in the future to boost host NKT cell-mediated immune responses against herpesviruses. IMPORTANCE Herpes simplex virus 1 (HSV-1) is among the most common human pathogens. Little is known regarding the exact mechanism by which this virus evades the human immune system, particularly the innate immune system. We previously reported that HSV-1 employs its protein kinase US3 to modulate the expression of the key antigen-presenting molecule CD1d to evade the antiviral function of NKT cells. Here we identified the key cellular motor protein KIF3A as a cellular substrate phosphorylated by US3, and this phosphorylation event mediates US3-induced immune evasion.
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Affiliation(s)
- Ran Xiong
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Ping Rao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Seil Kim
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Michelle Li
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Xiangshu Wen
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Weiming Yuan
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
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70
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Carpentier DCJ, Gao WND, Ewles H, Morgan GW, Smith GL. Vaccinia virus protein complex F12/E2 interacts with kinesin light chain isoform 2 to engage the kinesin-1 motor complex. PLoS Pathog 2015; 11:e1004723. [PMID: 25760349 PMCID: PMC4356562 DOI: 10.1371/journal.ppat.1004723] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2014] [Accepted: 02/01/2015] [Indexed: 11/18/2022] Open
Abstract
During vaccinia virus morphogenesis, intracellular mature virus (IMV) particles are wrapped by a double lipid bilayer to form triple enveloped virions called intracellular enveloped virus (IEV). IEV are then transported to the cell surface where the outer IEV membrane fuses with the cell membrane to expose a double enveloped virion outside the cell. The F12, E2 and A36 proteins are involved in transport of IEVs to the cell surface. Deletion of the F12L or E2L genes causes a severe inhibition of IEV transport and a tiny plaque size. Deletion of the A36R gene leads to a smaller reduction in plaque size and less severe inhibition of IEV egress. The A36 protein is present in the outer membrane of IEVs, and over-expressed fragments of this protein interact with kinesin light chain (KLC). However, no interaction of F12 or E2 with the kinesin complex has been reported hitherto. Here the F12/E2 complex is shown to associate with kinesin-1 through an interaction of E2 with the C-terminal tail of KLC isoform 2, which varies considerably between different KLC isoforms. siRNA-mediated knockdown of KLC isoform 1 increased IEV transport to the cell surface and virus plaque size, suggesting interaction with KLC isoform 1 is somehow inhibitory of IEV transport. In contrast, knockdown of KLC isoform 2 did not affect IEV egress or plaque formation, indicating redundancy in virion egress pathways. Lastly, the enhancement of plaque size resulting from loss of KLC isoform 1 was abrogated by removal of KLC isoforms 1 and 2 simultaneously. These observations suggest redundancy in the mechanisms used for IEV egress, with involvement of KLC isoforms 1 and 2, and provide evidence of interaction of F12/E2 complex with the kinesin-1 complex. Viruses often hijack the cellular transport systems to facilitate their movement within and between cells. Vaccinia virus (VACV), the smallpox vaccine, is very adept at this and exploits cellular transport machinery at several stages during its life cycle. For instance, during transport of new virus particles to the cell surface VACV interacts with a protein motor complex called kinesin-1 that moves cargo on microtubules. However, details of the cellular and viral components needed and the molecular mechanisms involved remain poorly understood. Hitherto, only the VACV protein A36 has been shown to interact with kinesin-1, however viruses lacking A36 still reach the cell surface, albeit at reduced efficiency, indicating other factors are involved. Here we describe an interaction between kinesin-1 and a complex of VACV proteins F12 and E2, which are both needed for virus transport. The F12/E2 complex associates with a subset of kinesin-1 molecules (kinesin light chain isoform 2) with a region thought to be involved in modulation of cargo binding and kinesin-1 motor activity. Further study of this interaction will enhance understanding of the VACV life cycle and of the roles of different kinesin-1 subtypes in cellular processes and the mechanisms that regulate them.
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Affiliation(s)
| | - William N. D. Gao
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Helen Ewles
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Gareth W. Morgan
- Department of Virology, Imperial College London, St. Mary’s Campus, London, United Kingdom
| | - Geoffrey L. Smith
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
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71
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Cdk1-dependent mitotic enrichment of cortical myosin II promotes cell rounding against confinement. Nat Cell Biol 2015; 17:148-59. [DOI: 10.1038/ncb3098] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Accepted: 12/17/2014] [Indexed: 12/16/2022]
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72
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Abstract
Cell shape is determined by cellular mechanics. Cell deformations in animal cells, such as those required for cell migration, division or epithelial morphogenesis, are largely controlled by changes in mechanical stress and tension at the cell surface. The plasma membrane and the actomyosin cortex control surface mechanics and determine cell surface tension. Tension in the actomyosin cortex primarily arises from myosin-generated stresses and depends strongly on the ultrastructural architecture of the network. Plasma membrane tension is controlled mainly by the surface area of the membrane relative to cell volume and can be modulated by changing membrane composition, shape and the organization of membrane-associated proteins. We review here our current understanding of the control of cortex and membrane tension by molecular processes. We particularly highlight the need for studies that bridge the scales between microscopic events and emergent properties at the cellular level. Finally, we discuss how the mechanical interplay between membrane dynamics and cortex contractility is key to understanding the biomechanical control of cell morphogenesis.
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73
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Yount AL, Zong H, Walczak CE. Regulatory mechanisms that control mitotic kinesins. Exp Cell Res 2015; 334:70-7. [PMID: 25576382 DOI: 10.1016/j.yexcr.2014.12.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 12/26/2014] [Indexed: 11/18/2022]
Abstract
During mitosis, the mitotic spindle is assembled to align chromosomes at the spindle equator in metaphase, and to separate the genetic material equally to daughter cells in anaphase. The spindle itself is a macromolecular machine composed of an array of dynamic microtubules and associated proteins that coordinate the diverse events of mitosis. Among the microtubule associated proteins are a plethora of molecular motor proteins that couple the energy of ATP hydrolysis to force production. These motors, including members of the kinesin superfamily, must function at the right time and in the right place to insure the fidelity of mitosis. Misregulation of mitotic motors in disease states, such as cancer, underlies their potential utility as targets for antitumor drug development and highlights the importance of understanding the molecular mechanisms for regulating their function. Here, we focus on recent progress about regulatory mechanisms that control the proper function of mitotic kinesins and highlight new findings that lay the path for future studies.
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Affiliation(s)
- Amber L Yount
- Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, IN 47405, United States
| | - Hailing Zong
- Department of Biology, Indiana University, Bloomington, IN 47405, United States
| | - Claire E Walczak
- Medical Sciences, Indiana University, Myers Hall 262, 915 East 3rd Street, Bloomington, IN 47405, United States.
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74
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Naito H, Goshima G. NACK Kinesin Is Required for Metaphase Chromosome Alignment and Cytokinesis in the Moss Physcomitrella Patens. Cell Struct Funct 2015; 40:31-41. [DOI: 10.1247/csf.14016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Haruko Naito
- Division of Biological Science, Graduate School of Science, Nagoya University
| | - Gohta Goshima
- Division of Biological Science, Graduate School of Science, Nagoya University
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75
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Chaperone-enhanced purification of unconventional myosin 15, a molecular motor specialized for stereocilia protein trafficking. Proc Natl Acad Sci U S A 2014; 111:12390-5. [PMID: 25114250 DOI: 10.1073/pnas.1409459111] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unconventional myosin 15 is a molecular motor expressed in inner ear hair cells that transports protein cargos within developing mechanosensory stereocilia. Mutations of myosin 15 cause profound hearing loss in humans and mice; however, the properties of this motor and its regulation within the stereocilia organelle are unknown. To address these questions, we expressed a subfragment 1-like (S1) truncation of mouse myosin 15, comprising the predicted motor domain plus three light-chain binding sites. Following unsuccessful attempts to express functional myosin 15-S1 using the Spodoptera frugiperda (Sf9)-baculovirus system, we discovered that coexpression of the muscle-myosin-specific chaperone UNC45B, in addition to the chaperone heat-shock protein 90 (HSP90) significantly increased the yield of functional protein. Surprisingly, myosin 15-S1 did not bind calmodulin with high affinity. Instead, the IQ domains bound essential and regulatory light chains that are normally associated with class II myosins. We show that myosin 15-S1 is a barbed-end-directed motor that moves actin filaments in a gliding assay (∼ 430 nm · s(-1) at 30 °C), using a power stroke of 7.9 nm. The maximum ATPase rate (k(cat) ∼ 6 s(-1)) was similar to the actin-detachment rate (k(det) = 6.2 s(-1)) determined in single molecule optical trapping experiments, indicating that myosin 15-S1 was rate limited by transit through strongly actin-bound states, similar to other processive myosin motors. Our data further indicate that in addition to folding muscle myosin, UNC45B facilitates maturation of an unconventional myosin. We speculate that chaperone coexpression may be a simple method to optimize the purification of other myosin motors from Sf9 insect cells.
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76
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Endogenous localizome identifies 43 mitotic kinesins in a plant cell. Proc Natl Acad Sci U S A 2014; 111:E1053-61. [PMID: 24591632 DOI: 10.1073/pnas.1311243111] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Kinesins are microtubule (MT)-based motor proteins that have been identified in every eukaryotic species. Intriguingly, land plants have more than 60 kinesins in their genomes, many more than that in yeasts or animals. However, many of these have not yet been characterized, and their cellular functions are unknown. Here, by using endogenous tagging, we comprehensively determined the localization of 72 kinesins during mitosis in the moss Physcomitrella patens. We found that 43 kinesins are localized to mitotic structures such as kinetochores, spindle MTs, or phragmoplasts, which are MT-based structures formed during cytokinesis. Surprisingly, only one of them showed an identical localization pattern to the animal homolog, and many were enriched at unexpected sites. RNA interference and live-cell microscopy revealed postanaphase roles for kinesin-5 in spindle/phragmoplast organization, chromosome segregation, and cytokinesis, which have not been observed in animals. Our study thus provides a list of MT-based motor proteins associated with the cell division machinery in plants. Furthermore, our data challenge the current generalization of determining mitotic kinesin function based solely on studies using yeast and animal cells.
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77
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Goto-Silva L, Maliga Z, Slabicki M, Murillo JR, Junqueira M. Application of shotgun proteomics for discovery-driven protein-protein interaction. Methods Mol Biol 2014; 1156:265-278. [PMID: 24791995 DOI: 10.1007/978-1-4939-0685-7_18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Affinity purification of protein complexes and identification of co-purified proteins by mass spectrometry is a powerful method to discover novel protein-protein interactions. Application of this method to the study of biological systems often requires the ability to process a large number of samples. Hence, there is great need to generate proteomic workflows compatible with large-scale studies. The major goal of this protocol is to present a fast, reliable, and scalable method to characterize protein complexes by mass spectrometry to overcome the limitations of conventional geLC-MS/MS or MudPIT protocols. This method was successfully employed for the discovery and characterization of novel protein complexes in cultured yeast, mammalian cells, and mice.
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Affiliation(s)
- Livia Goto-Silva
- Proteomics Unit, Institute of Chemistry, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, 21941-909, Brazil
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78
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Abstract
Much of what is known about mammalian cell regulation has been achieved with the aid of transiently transfected cells. However, overexpression can violate balanced gene dosage, affecting protein folding, complex assembly and downstream regulation. To avoid these problems, genome engineering technologies now enable the generation of stable cell lines expressing modified proteins at (almost) native levels.
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Affiliation(s)
- Toby J Gibson
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany.
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79
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Nachbar J, Lázaro-Diéguez F, Prekeris R, Cohen D, Müsch A. KIFC3 promotes mitotic progression and integrity of the central spindle in cytokinesis. Cell Cycle 2013; 13:426-33. [PMID: 24275865 DOI: 10.4161/cc.27266] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Kinesin-14 motor proteins play a variety of roles during metaphase and anaphase. However, it is not known whether members of this family of motors also participate in the dramatic changes in mitotic spindle organization during the transition from telophase to cytokinesis. We have identified the minus-end-directed motor, KIFC3, as an important contributor to central bridge morphology at this stage. KIFC3's unique motor-dependent localization at the central bridge allows it to congress microtubules, promoting efficient progress through cytokinesis. Conversely, when KIFC3 function is perturbed, abscission is delayed, and the central bridge is both widened and extended. Examination of KIFC3 on growing microtubules in interphase indicates that it caps microtubules released from the centrosome, both in the region of the centrosome and in the cell periphery. In line with other kinesin-14 family members, KIFC3 may guide free microtubules to their destination at the bridge and/or may slide and crosslink central bridge microtubules in order to stage the cells for abscission.
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Affiliation(s)
- Jeannette Nachbar
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; New York, NY USA
| | - Francisco Lázaro-Diéguez
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; New York, NY USA
| | | | - David Cohen
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; New York, NY USA
| | - Anne Müsch
- Department of Developmental and Molecular Biology; Albert Einstein College of Medicine; New York, NY USA
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80
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Syred HM, Welburn J, Rappsilber J, Ohkura H. Cell cycle regulation of microtubule interactomes: multi-layered regulation is critical for the interphase/mitosis transition. Mol Cell Proteomics 2013; 12:3135-47. [PMID: 23893837 PMCID: PMC3820929 DOI: 10.1074/mcp.m113.028563] [Citation(s) in RCA: 25] [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: 02/20/2013] [Revised: 07/25/2013] [Indexed: 12/17/2022] Open
Abstract
Microtubules dramatically change their dynamics and organization at the entry into mitosis. Although this change is mediated by microtubule-associated proteins (MAPs), how MAPs themselves are regulated is not well understood. Here we used an integrated multi-level approach to establish the framework and biological significance of MAP regulation critical for the interphase/mitosis transition. Firstly, we applied quantitative proteomics to determine global cell cycle changes in the profiles of MAPs in human and Drosophila cells. This uncovered a wide range of cell cycle regulations of MAPs previously unidentified. Secondly, systematic studies of human kinesins highlighted an overlooked aspect of kinesins: most mitotic kinesins suppress their affinity to microtubules or reduce their protein levels in interphase in combination with nuclear localization. Thirdly, in-depth analysis of a novel Drosophila MAP (Mink) revealed that the suppression of the microtubule affinity of this mitotic MAP in combination with nuclear localization is essential for microtubule organization in interphase, and phosphorylation of Mink is needed for kinetochore-microtubule attachment in mitosis. Thus, this first comprehensive analysis of MAP regulation for the interphase/mitosis transition advances our understanding of kinesin biology and reveals the prevalence and importance of multi-layered MAP regulation.
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Affiliation(s)
- Heather M. Syred
- From the ‡Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Julie Welburn
- From the ‡Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Juri Rappsilber
- From the ‡Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
| | - Hiroyuki Ohkura
- From the ‡Wellcome Trust Centre for Cell Biology, School of Biological Sciences, The University of Edinburgh, Edinburgh EH9 3JR, United Kingdom
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81
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Janisch KM, Vock VM, Fleming MS, Shrestha A, Grimsley-Myers CM, Rasoul BA, Neale SA, Cupp TD, Kinchen JM, Liem KF, Dwyer ND. The vertebrate-specific Kinesin-6, Kif20b, is required for normal cytokinesis of polarized cortical stem cells and cerebral cortex size. Development 2013; 140:4672-82. [PMID: 24173802 DOI: 10.1242/dev.093286] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Mammalian neuroepithelial stem cells divide using a polarized form of cytokinesis, which is not well understood. The cytokinetic furrow cleaves the cell by ingressing from basal to apical, forming the midbody at the apical membrane. The midbody mediates abscission by recruiting many factors, including the Kinesin-6 family member Kif20b. In developing embryos, Kif20b mRNA is most highly expressed in neural stem/progenitor cells. A loss-of-function mutant in Kif20b, magoo, was found in a forward genetic screen. magoo has a small cerebral cortex, with reduced production of progenitors and neurons, but preserved layering. In contrast to other microcephalic mouse mutants, mitosis and cleavage furrows of cortical stem cells appear normal in magoo. However, apical midbodies show changes in number, shape and positioning relative to the apical membrane. Interestingly, the disruption of abscission does not appear to result in binucleate cells, but in apoptosis. Thus, Kif20b is required for proper midbody organization and abscission in polarized cortical stem cells and has a crucial role in the regulation of cerebral cortex growth.
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Affiliation(s)
- Kerstin M Janisch
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908, USA
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82
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Welburn JPI. The molecular basis for kinesin functional specificity during mitosis. Cytoskeleton (Hoboken) 2013; 70:476-93. [PMID: 24039047 PMCID: PMC4065354 DOI: 10.1002/cm.21135] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 07/24/2013] [Accepted: 08/21/2013] [Indexed: 12/13/2022]
Abstract
Microtubule-based motor proteins play key roles during mitosis to assemble the bipolar spindle, define the cell division axis, and align and segregate the chromosomes. The majority of mitotic motors are members of the kinesin superfamily. Despite sharing a conserved catalytic core, each kinesin has distinct functions and localization, and is uniquely regulated in time and space. These distinct behaviors and functional specificity are generated by variations in the enzymatic domain as well as the non-conserved regions outside of the kinesin motor domain and the stalk. These flanking regions can directly modulate the properties of the kinesin motor through dimerization or self-interactions, and can associate with extrinsic factors, such as microtubule or DNA binding proteins, to provide additional functional properties. This review discusses the recently identified molecular mechanisms that explain how the control and functional specification of mitotic kinesins is achieved. © 2013 Wiley Periodicals, Inc.
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Affiliation(s)
- Julie P I Welburn
- Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JR, Scotland, United Kingdom
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83
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Song H, Zhou S, Wang R, Li S. Kinesin spindle protein (KSP) inhibitors in combination with chemotherapeutic agents for cancer therapy. ChemMedChem 2013; 8:1736-49. [PMID: 23964020 DOI: 10.1002/cmdc.201300228] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 07/20/2013] [Indexed: 12/20/2022]
Abstract
A diverse group of proteins, the activities of which are precisely orchestrated during mitosis, have emerged as targets for cancer therapeutics; these include the Aurora kinases (AKs), Polo-like kinases (PLKs), and the kinesin spindle protein (KSP). KSP is essential for the proper separation of spindle poles during mitosis. Agents that target KSP selectively act on cells undergoing cell division, which means that KSP inhibitors are mitosis-specific drugs, and have demonstrated remarkable activities in vitro. However, a significant obstacle to the success of KSP inhibitors is that these compounds, with tremendous efficacy in vitro, have demonstrated little or even no antitumor activity in vivo. Accumulated data suggest that a combination of KSP inhibitors with various cytostatic drugs will result in a more powerful tumor-killing effect than monotherapy. Combination therapies might predominate and represent the next frontier in the discovery research of KSP inhibitors as potential anticancer drugs. Few published studies have reviewed combination therapy using KSP inhibitors. Herein we provide a comprehensive review of the literature on KSP inhibitor monotherapy and therapeutic combinations. The current state and problems are also discussed.
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Affiliation(s)
- Hualong Song
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai (PR China)
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84
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Kinesin-5: cross-bridging mechanism to targeted clinical therapy. Gene 2013; 531:133-49. [PMID: 23954229 DOI: 10.1016/j.gene.2013.08.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/29/2013] [Accepted: 08/02/2013] [Indexed: 12/28/2022]
Abstract
Kinesin motor proteins comprise an ATPase superfamily that works hand in hand with microtubules in every eukaryote. The mitotic kinesins, by virtue of their potential therapeutic role in cancerous cells, have been a major focus of research for the past 28 years since the discovery of the canonical Kinesin-1 heavy chain. Perhaps the simplest player in mitotic spindle assembly, Kinesin-5 (also known as Kif11, Eg5, or kinesin spindle protein, KSP) is a plus-end-directed motor localized to interpolar spindle microtubules and to the spindle poles. Comprised of a homotetramer complex, its function primarily is to slide anti-parallel microtubules apart from one another. Based on multi-faceted analyses of this motor from numerous laboratories over the years, we have learned a great deal about the function of this motor at the atomic level for catalysis and as an integrated element of the cytoskeleton. These data have, in turn, informed the function of motile kinesins on the whole, as well as spearheaded integrative models of the mitotic apparatus in particular and regulation of the microtubule cytoskeleton in general. We review what is known about how this nanomotor works, its place inside the cytoskeleton of cells, and its small-molecule inhibitors that provide a toolbox for understanding motor function and for anticancer treatment in the clinic.
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Farina F, Pierobon P, Delevoye C, Monnet J, Dingli F, Loew D, Quanz M, Dutreix M, Cappello G. Kinesin KIFC1 actively transports bare double-stranded DNA. Nucleic Acids Res 2013; 41:4926-37. [PMID: 23543461 PMCID: PMC3643607 DOI: 10.1093/nar/gkt204] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
During the past years, exogenous DNA molecules have been used in gene and molecular therapy. At present, it is not known how these DNA molecules reach the cell nucleus. We used an in cell single-molecule approach to observe the motion of exogenous short DNA molecules in the cytoplasm of eukaryotic cells. Our observations suggest an active transport of the DNA along the cytoskeleton filaments. We used an in vitro motility assay, in which the motion of single-DNA molecules along cytoskeleton filaments in cell extracts is monitored; we demonstrate that microtubule-associated motors are involved in this transport. Precipitation of DNA-bound proteins and mass spectrometry analyses reveal the preferential binding of the kinesin KIFC1 on DNA. Cell extract depletion of kinesin KIFC1 significantly decreases DNA motion, confirming the active implication of this molecular motor in the intracellular DNA transport.
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Affiliation(s)
- Francesca Farina
- Physico-Chimie-Curie/UMR168 Institut Curie, Centre National de la Recherche Scientifique, Université Pierre et Marie Curie, 75231 Paris, France
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