200 results match your criteria purified centrosomes

Assembly of the asymmetric human γ-tubulin ring complex by RUVBL1-RUVBL2 AAA ATPase.

Sci Adv 2020 Dec 18;6(51). Epub 2020 Dec 18.

Mechanisms of Disease Programme, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain.

The microtubule nucleator γ-tubulin ring complex (γTuRC) is essential for the function of microtubule organizing centers such as the centrosome. Since its discovery over two decades ago, γTuRC has evaded in vitro reconstitution and thus detailed structure-function studies. Here, we show that a complex of RuvB-like protein 1 (RUVBL1) and RUVBL2 "RUVBL" controls assembly and composition of γTuRC in human cells. Read More

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December 2020

The nucleus serves as the pacemaker for the cell cycle.

Elife 2020 12 7;9. Epub 2020 Dec 7.

Department of Chemical and Systems Biology, Stanford Medicine, Stanford, United States.

Mitosis is a dramatic process that affects all parts of the cell. It is driven by an oscillator whose various components are localized in the nucleus, centrosome, and cytoplasm. In principle, the cellular location with the fastest intrinsic rhythm should act as a pacemaker for the process. Read More

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December 2020

Phase separation of the Cep63•Cep152 complex underlies the formation of dynamic supramolecular self-assemblies at human centrosomes.

Cell Cycle 2020 12 18;19(24):3437-3457. Epub 2020 Nov 18.

Laboratory of Metabolism, National Cancer Institute, National Institutes of Health , Bethesda, MD, USA.

The centrosome is a unique membraneless organelle that plays a pivotal role in the orderly progression of the cell cycle in animal cells. It has been shown that two pericentriolar scaffold proteins, Cep63 and Cep152, generate a heterotetrameric complex to self-assemble into a higher-order cylindrical architecture around a centriole. However, the mechanisms underlying how they reach their threshold concentrations in the vast intracellular space and generate a self-assembled architecture remain mysterious. Read More

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December 2020

The ARF GAP ELMOD2 acts with different GTPases to regulate centrosomal microtubule nucleation and cytokinesis.

Mol Biol Cell 2020 08 2;31(18):2070-2091. Epub 2020 Jul 2.

Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322.

ELMOD2 is a ∼32 kDa protein first purified by its GTPase-activating protein (GAP) activity toward ARL2 and later shown to have uniquely broad specificity toward ARF family GTPases in in vitro assays. To begin the task of defining its functions in cells, we deleted ELMOD2 in immortalized mouse embryonic fibroblasts and discovered a number of cellular defects, which are reversed upon expression of ELMOD2-myc. We show that these defects, resulting from the loss of ELMOD2, are linked to two different pathways and two different GTPases: with ARL2 and TBCD to support microtubule nucleation from centrosomes and with ARF6 in cytokinesis. Read More

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Homogeneous multifocal excitation for high-throughput super-resolution imaging.

Nat Methods 2020 07 22;17(7):726-733. Epub 2020 Jun 22.

Laboratory for Experimental Biophysics, Institute of Physics, Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland.

Super-resolution microscopies have become an established tool in biological research. However, imaging throughput remains a main bottleneck in acquiring large datasets required for quantitative biology. Here we describe multifocal flat illumination for field-independent imaging (mfFIFI). Read More

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Actin filaments regulate microtubule growth at the centrosome.

EMBO J 2019 06 22;38(11). Epub 2019 Mar 22.

CEA, CNRS, INRA, Biosciences & Biotechnology Institute of Grenoble, UMR5168, CytoMorpho Lab, Univ. Grenoble-Alpes, Grenoble, France

The centrosome is the main microtubule-organizing centre. It also organizes a local network of actin filaments. However, the precise function of the actin network at the centrosome is not well understood. Read More

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The Protein Phosphorylation Landscape of Mouse Spermatids during Spermiogenesis.

Proteomics 2019 06 8;19(11):e1900055. Epub 2019 May 8.

State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing, 210029, China.

The characteristic tadpole shape of sperm is formed from round spermatids via spermiogenesis, a process which results in dramatic morphological changes in the final stage of spermatogenesis in the testis. Protein phosphorylation, as one of the most important post-translational modifications, can regulate spermiogenesis; however, the phosphorylation events taking place during this process have not been systematically analyzed. In order to better understand the role of phosphorylation in spermiogenesis, large-scale phosphoproteome profiling is performed using IMAC and TiO enrichment. Read More

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Reconstruction From Multiple Particles for 3D Isotropic Resolution in Fluorescence Microscopy.

IEEE Trans Med Imaging 2018 05;37(5):1235-1246

The imaging of proteins within macromolecular complexes has been limited by the low axial resolution of optical microscopes. To overcome this problem, we propose a novel computational reconstruction method that yields isotropic resolution in fluorescence imaging. The guiding principle is to reconstruct a single volume from the observations of multiple rotated particles. Read More

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SPIRAL2 Stabilises Endoplasmic Microtubule Minus Ends in the Moss Physcomitrella patens.

Cell Struct Funct 2018 03 15;43(1):53-60. Epub 2018 Mar 15.

Division of Biological Science, Graduate School of Science, Nagoya University.

Stabilisation of minus ends of microtubules (MTs) is critical for organising MT networks in land plant cells, in which all MTs are nucleated independent of centrosomes. Recently, Arabidopsis SPIRAL2 (SPR2) protein was shown to localise to plus and minus ends of cortical MTs, and increase stability of both ends. Here, we report molecular and functional characterisation of SPR2 of the basal land plant, the moss Physcomitrella patens. Read More

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Redox modulation of NQO1.

PLoS One 2018 3;13(1):e0190717. Epub 2018 Jan 3.

Department of Pharmaceutical Sciences, Skaggs School of Pharmacy, University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America.

NQO1 is a FAD containing NAD(P)H-dependent oxidoreductase that catalyzes the reduction of quinones and related substrates. In cells, NQO1 participates in a number of binding interactions with other proteins and mRNA and these interactions may be influenced by the concentrations of reduced pyridine nucleotides. NAD(P)H can protect NQO1 from proteolytic digestion suggesting that binding of reduced pyridine nucleotides results in a change in NQO1 structure. Read More

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February 2018

Phosphatase PP2A and microtubule-mediated pulling forces disassemble centrosomes during mitotic exit.

Biol Open 2018 Jan 12;7(1). Epub 2018 Jan 12.

Department of Cell Biology, Department of Biophysics, UT Southwestern Medical Center, Dallas, TX 75390, USA

Centrosomes are microtubule-nucleating organelles that facilitate chromosome segregation and cell division in metazoans. Centrosomes comprise centrioles that organize a micron-scale mass of protein called pericentriolar material (PCM) from which microtubules nucleate. During each cell cycle, PCM accumulates around centrioles through phosphorylation-mediated assembly of PCM scaffold proteins. Read More

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January 2018

Biochemical and Biophysical characterization of curcumin binding to human mitotic kinesin Eg5: Insights into the inhibitory mechanism of curcumin on Eg5.

Int J Biol Macromol 2018 Apr 21;109:1189-1208. Epub 2017 Nov 21.

School of Biotechnology, National Institute of Technology Calicut, Calicut, Kerala, India. Electronic address:

In this study we have characterized the biochemical and biophysical interactions of curcumin with the mitotic kinesin Eg5 which plays a pivotal role in the separation of centrosomes during cell division. Curcumin bound to the purified Eg5 (Eg5-437H) with a K value of 7.8μM. Read More

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Identification of Chlamydomonas Central Core Centriolar Proteins Reveals a Role for Human WDR90 in Ciliogenesis.

Curr Biol 2017 Aug 3;27(16):2486-2498.e6. Epub 2017 Aug 3.

Swiss Institute for Experimental Cancer Research (ISREC), School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne 1015, Switzerland. Electronic address:

Centrioles are evolutionarily conserved macromolecular structures that are fundamental to form cilia, flagella, and centrosomes. Centrioles are 9-fold symmetrical microtubule-based cylindrical barrels comprising three regions that can be clearly distinguished in the Chlamydomonas reinhardtii organelle: an ∼100-nm-long proximal region harboring a cartwheel; an ∼250-nm-long central core region containing a Y-shaped linker; and an ∼150-nm-long distal region ending at the transitional plate. Despite the discovery of many centriolar components, no protein has been localized specifically to the central core region in Chlamydomonas thus far. Read More

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A centrosomal protein FOR20 regulates microtubule assembly dynamics and plays a role in cell migration.

Biochem J 2017 08 10;474(16):2841-2859. Epub 2017 Aug 10.

Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Mumbai 400076, India

Here, we report that a centrosomal protein FOR20 [FOP (FGFR1 (fibroblast growth factor receptor 1) oncogene protein)-like protein of molecular mass of 20 kDa; also named as C16orf63, FLJ31153 or PHSECRG2] can regulate the assembly and stability of microtubules. Both FOR20 IgG antibody and GST (glutathione -transferase)-tagged FOR20 could precipitate tubulin from the HeLa cell extract, indicating a possible interaction between FOR20 and tubulin. FOR20 was also detected in goat brain tissue extract and it cycled with microtubule-associated proteins. Read More

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Direct measurement of the strength of microtubule attachment to yeast centrosomes.

Mol Biol Cell 2017 Jul 22;28(14):1853-1861. Epub 2017 Mar 22.

Department of Physiology and Biophysics, University of Washington, Seattle, WA 98195

Centrosomes, or spindle pole bodies (SPBs) in yeast, are vital mechanical hubs that maintain load-bearing attachments to microtubules during mitotic spindle assembly, spindle positioning, and chromosome segregation. However, the strength of microtubule-centrosome attachments is unknown, and the possibility that mechanical force might regulate centrosome function has scarcely been explored. To uncover how centrosomes sustain and regulate force, we purified SPBs from budding yeast and used laser trapping to manipulate single attached microtubules in vitro. Read More

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Re-evaluating the roles of myosin 18Aα and F-actin in determining Golgi morphology.

Cytoskeleton (Hoboken) 2017 May 10;74(5):205-218. Epub 2017 May 10.

Cell Biology and Physiology Center, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.

The peri-centrosomal localization and morphology of the Golgi apparatus depends largely on the microtubule cytoskeleton and the microtubule motor protein dynein. Recent studies proposed that myosin 18Aα (M18Aα) also contributes to Golgi morphology by binding the Golgi protein GOLPH3 and walking along adjacent actin filaments to stretch the Golgi into its classic ribbon structure. Biochemical analyses have shown, however, that M18A is not an actin-activated ATPase and lacks motor activity. Read More

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Polo-like kinase phosphorylation determines Caenorhabditis elegans centrosome size and density by biasing SPD-5 toward an assembly-competent conformation.

Biol Open 2016 Oct 15;5(10):1431-1440. Epub 2016 Oct 15.

Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, Dresden 01307, Germany

Centrosomes are major microtubule-organizing centers composed of centrioles surrounded by an extensive proteinacious layer called the pericentriolar material (PCM). In Caenorhabditis elegans embryos, the mitotic PCM expands by Polo-like kinase 1 (PLK-1) phosphorylation-accelerated assembly of SPD-5 molecules into supramolecular scaffolds. However, how PLK-1 phosphorylation regulates SPD-5 assembly is not known. Read More

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October 2016

Cell-Type-Specific Alternative Splicing Governs Cell Fate in the Developing Cerebral Cortex.

Cell 2016 Aug;166(5):1147-1162.e15

Division of Genetics and Genomics, Manton Center for Orphan Disease Research, Howard Hughes Medical Institute, Boston Children's Hospital, Boston, MA 02115, USA; Departments of Neurology and Pediatrics, Harvard Medical School, Boston, MA 02115, USA; Harvard Stem Cell Institute, Cambridge, MA 02138, USA; Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA. Electronic address:

Alternative splicing is prevalent in the mammalian brain. To interrogate the functional role of alternative splicing in neural development, we analyzed purified neural progenitor cells (NPCs) and neurons from developing cerebral cortices, revealing hundreds of differentially spliced exons that preferentially alter key protein domains-especially in cytoskeletal proteins-and can harbor disease-causing mutations. We show that Ptbp1 and Rbfox proteins antagonistically govern the NPC-to-neuron transition by regulating neuron-specific exons. Read More

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Quantitative analysis of human centrosome architecture by targeted proteomics and fluorescence imaging.

EMBO J 2016 10 18;35(19):2152-2166. Epub 2016 Aug 18.

Biozentrum, University of Basel, Basel, Switzerland

Centrioles are essential for the formation of centrosomes and cilia. While numerical and/or structural centrosomes aberrations are implicated in cancer, mutations in centriolar and centrosomal proteins are genetically linked to ciliopathies, microcephaly, and dwarfism. The evolutionarily conserved mechanisms underlying centrosome biogenesis are centered on a set of key proteins, including Plk4, Sas-6, and STIL, whose exact levels are critical to ensure accurate reproduction of centrioles during cell cycle progression. Read More

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October 2016

Excess free histone H3 localizes to centrosomes for proteasome-mediated degradation during mitosis in metazoans.

Cell Cycle 2016 Aug 1;15(16):2216-2225. Epub 2016 Jun 1.

a Department of Epigenetics and Molecular Carcinogenesis , University of Texas MD Anderson Cancer Center , Houston , TX , USA.

The cell tightly controls histone protein levels in order to achieve proper packaging of the genome into chromatin, while avoiding the deleterious consequences of excess free histones. Our accompanying study has shown that a histone modification that loosens the intrinsic structure of the nucleosome, phosphorylation of histone H3 on threonine 118 (H3 T118ph), exists on centromeres and chromosome arms during mitosis. Here, we show that H3 T118ph localizes to centrosomes in humans, flies, and worms during all stages of mitosis. Read More

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A Cell-Free System for Real-Time Analyses of Centriole Disengagement and Centriole-to-Centrosome Conversion.

Methods Mol Biol 2016 ;1413:197-206

Cell Biology Program, Memorial Sloan Kettering Cancer Center, 1275 York Ave., New York, NY, 10065, USA.

Centriole or centrosome number in cycling cells is strictly maintained through coordinated duplication and segregation. Duplication is limited to once only per cell cycle by separating the assembly event that occurs in S/G2 phase from the two licensing events, centriole disengagement and centriole-to-centrosome conversion, both of which occurs in mitosis. In addition to duplication licensing, centriole-to-centrosome conversion also enables centrioles to associate with spindle poles and thereby to segregate equally during cell division. Read More

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December 2017

Purification of Fluorescently Labeled Saccharomyces cerevisiae Spindle Pole Bodies.

Methods Mol Biol 2016 ;1413:189-195

Department of Biochemistry, University of Washington, Seattle, WA 98195.

Centrosomes are components of the mitotic spindle responsible for organizing microtubules and establishing a bipolar spindle for accurate chromosome segregation. In budding yeast, Saccharomyces cerevisiae, the centrosome is called the spindle pole body, a highly organized trilaminar structure embedded in the nuclear envelope. Here we describe a detailed protocol for the purification of fluorescently labeled spindle pole bodes from S. Read More

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December 2017

Centlein, a novel microtubule-associated protein stabilizing microtubules and involved in neurite formation.

Biochem Biophys Res Commun 2016 Apr 23;472(2):360-5. Epub 2016 Feb 23.

Savaid School of Medicine, University of Chinese Academy of Sciences, Beijing 100049, China. Electronic address:

We have previously reported that the centriolar protein centlein functions as a molecular link between C-Nap1 and Cep68 to maintain centrosome cohesion [1]. In this study, we identified centlein as a novel microtubule-associated protein (MAP), directly binding to purified microtubules (MTs) via its longest coiled-coil domain. Overexpression of centlein caused profound nocodazole- and cold-resistant MT bundles, which also relied on its MT-binding domain. Read More

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The Deubiquitinase USP37 Regulates Chromosome Cohesion and Mitotic Progression.

Curr Biol 2015 Aug 20;25(17):2290-9. Epub 2015 Aug 20.

Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada. Electronic address:

A bipolar mitotic spindle facilitates the equal segregation of chromosomes to two daughter cells. To achieve bipolar attachment of microtubules to kinetochores of sister chromatids, chromatids must remain paired after replication. This cohesion is mediated by the conserved cohesin complex comprised of SMC1, SMC3, SCC1, and either SA1 or SA2 in humans. Read More

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Purification of centrosomes from mammalian cell lines.

Methods Cell Biol 2015 27;129:171-189. Epub 2015 May 27.

Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris Sud, Gif sur Yvette, France.

Centrosomes act as the main microtubule-organizing centre of animal cells and play critical roles in the cell, such as mitotic spindle organization, cell polarity, and motility. They are composed of two barrel-shaped structures, the centrioles, surrounded by the pericentriolar matrix. In mammalian cells, the two centrioles differ structurally due to generational difference, the oldest one bearing appendages which allow the transient docking of the centriole at the plasma membrane in order to grow a primary cilium. Read More

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Centrosomal nucleolin is required for microtubule network organization.

Cell Cycle 2015 ;14(6):902-19

a Université de Lyon; Ecole Normale Supérieure de Lyon; CNRS USR 3010; Laboratoire Joliot-Curie ; Lyon , France.

Nucleolin is a pleiotropic protein involved in a variety of cellular processes. Although multipolar spindle formation has been observed after nucleolin depletion, the roles of nucleolin in centrosome regulation and functions have not been addressed. Here we report using immunofluorescence and biochemically purified centrosomes that nucleolin co-localized only with one of the centrioles during interphase which was further identified as the mature centriole. Read More

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December 2015

Ensconsin/Map7 promotes microtubule growth and centrosome separation in Drosophila neural stem cells.

J Cell Biol 2014 Mar;204(7):1111-21

Cytoskeleton and Cell Proliferation, 2 Tubulin and Interacting Proteins, and 3 Spatio-temporal Regulation of Transcription, Biosit, Université de Rennes I, Centre National de la Recherche Scientifique, UMR 6290, 35043 Rennes, France.

The mitotic spindle is crucial to achieve segregation of sister chromatids. To identify new mitotic spindle assembly regulators, we isolated 855 microtubule-associated proteins (MAPs) from Drosophila melanogaster mitotic or interphasic embryos. Using RNAi, we screened 96 poorly characterized genes in the Drosophila central nervous system to establish their possible role during spindle assembly. Read More

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Assaying microtubule nucleation by the γ-tubulin ring complex.

Methods Enzymol 2014 ;540:119-30

Division of Life Science, The Hong Kong University of Science and Technology, Hong Kong, China. Electronic address:

Microtubule organization by microtubule-organizing centers such as the centrosome requires γ-tubulin, which exists in the γ-tubulin ring complex (γTuRC) that nucleates microtubules. The γTuRC is a ring-shaped, macromolecular complex whose core components are γ-tubulin and the γ-tubulin complex proteins. Despite the recent identification of additional γTuRC components, the molecular composition and regulatory properties of the complex remain poorly understood. Read More

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November 2014

Microtubule minus-end stabilization by polymerization-driven CAMSAP deposition.

Dev Cell 2014 Feb 30;28(3):295-309. Epub 2014 Jan 30.

Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 Utrecht, the Netherlands. Electronic address:

Microtubules are cytoskeletal polymers with two structurally and functionally distinct ends, the plus- and the minus-end. Here, we focus on the mechanisms underlying the regulation of microtubule minus-ends by the CAMSAP/Nezha/Patronin protein family. We show that CAMSAP2 is required for the proper organization and stabilization of interphase microtubules and directional cell migration. Read More

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February 2014

Polo-like kinase 4 autodestructs by generating its Slimb-binding phosphodegron.

Curr Biol 2013 Nov 31;23(22):2255-2261. Epub 2013 Oct 31.

Department of Cellular and Molecular Medicine, University of Arizona Cancer Center, University of Arizona, Tucson, AZ 85724, USA. Electronic address:

Polo-like kinase 4 (Plk4) is a conserved master regulator of centriole assembly. Previously, we found that Drosophila Plk4 protein levels are actively suppressed during interphase. Degradation of interphase Plk4 prevents centriole overduplication and is mediated by the ubiquitin-ligase complex SCF(Slimb/βTrCP). Read More

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November 2013