718 results match your criteria spindle elongation


Differential regulation of single microtubules and bundles by a three-protein module.

Nat Chem Biol 2021 Jun 3. Epub 2021 Jun 3.

Department of Molecular Biology, Massachusetts General Hospital, Boston, MA, USA.

A remarkable feature of the microtubule cytoskeleton is the coexistence of subpopulations having different dynamic properties. A prominent example is the anaphase spindle, where stable antiparallel bundles exist alongside dynamic microtubules and provide spatial cues for cytokinesis. How are the dynamics of spatially proximal arrays differentially regulated? We reconstitute a minimal system of three midzone proteins: microtubule-crosslinker PRC1 and its interactors CLASP1 and Kif4A, proteins that promote and suppress microtubule elongation, respectively. Read More

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Kinesin-6 Klp9 orchestrates spindle elongation by regulating microtubule sliding and growth.

Elife 2021 Jun 3;10. Epub 2021 Jun 3.

Institut Curie, PSL Research University, Sorbonne Université CNRS, UMR 144, Paris, France.

Mitotic spindle function depends on the precise regulation of microtubule dynamics and microtubule sliding. Throughout mitosis, both processes have to be orchestrated to establish and maintain spindle stability. We show that during anaphase B spindle elongation in , the sliding motor Klp9 (kinesin-6) also promotes microtubule growth in vivo. Read More

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The multifunctional spindle midzone in vertebrate cells at a glance.

J Cell Sci 2021 May 27;134(10). Epub 2021 May 27.

Department of Biology, Morrill Science Center, University of Massachusetts, 611 N. Pleasant Street, Amherst 01003, USA.

During anaphase, a microtubule-containing structure called the midzone forms between the segregating chromosomes. The midzone is composed of an antiparallel array of microtubules and numerous microtubule-associated proteins that contribute to midzone formation and function. In many cells, the midzone is an important source of signals that specify the location of contractile ring assembly and constriction. Read More

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A Case Report on the Dermoscopic Features of Spark's Nevus.

Ann Dermatol 2020 Jun 24;32(3):233-236. Epub 2020 Apr 24.

Department of Dermatology, Kosin University College of Medicine, Busan, Korea.

Spark's nevus is a compound word composed of Spitz nevus and Clark's nevus. It is one of the combined melanocytic nevi which is more common in female and usually presents as a sharp circumscribed hyperpigmented macule on the lower extremities. On histopathologic findings, both cytologic features of Spitz nevus characterized as large spindle or epithelioid melanocytes containing large nuclei with abundant cytoplasm, and architecture of Clark's nevus characterized as elongation of rete ridges, bridging of the nests, concentric and lamellar fibrosis can be seen. Read More

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Microtubule-sliding modules based on kinesins EG5 and PRC1-dependent KIF4A drive human spindle elongation.

Dev Cell 2021 May 27;56(9):1253-1267.e10. Epub 2021 Apr 27.

Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address:

Proper chromosome segregation into two future daughter cells requires the mitotic spindle to elongate in anaphase. However, although some candidate proteins are implicated in this process, the molecular mechanism that drives spindle elongation in human cells is unknown. Using combined depletion and inactivation assays together with CRISPR technology to explore redundancy between multiple targets, we discovered that the force-generating mechanism of spindle elongation consists of EG5/kinesin-5 together with the PRC1-dependent motor KIF4A/kinesin-4, with contribution from kinesin-6 and kinesin-8. Read More

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Anaphase B: Long-standing models meet new concepts.

Semin Cell Dev Biol 2021 Apr 10. Epub 2021 Apr 10.

Division of Molecular Biology, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia. Electronic address:

Mitotic cell divisions ensure stable transmission of genetic information from a mother to daughter cells in a series of generations. To ensure this crucial task is accomplished, the cell forms a bipolar structure called the mitotic spindle that divides sister chromatids to the opposite sides of the dividing mother cell. After successful establishment of stable attachments of microtubules to chromosomes and inspection of connections between them, at the heart of mitosis, the cell starts the process of segregation. Read More

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Trypanosome KKIP1 Dynamically Links the Inner Kinetochore to a Kinetoplastid Outer Kinetochore Complex.

Front Cell Infect Microbiol 2021 23;11:641174. Epub 2021 Mar 23.

School of Life Sciences, University of Nottingham, Nottingham, United Kingdom.

Kinetochores perform an essential role in eukaryotes, coupling chromosomes to the mitotic spindle. In model organisms they are composed of a centromere-proximal inner kinetochore and an outer kinetochore network that binds to microtubules. In spite of universal function, the composition of kinetochores in extant eukaryotes differs greatly. Read More

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First report of chili pepper fruit rot caused by Fusarium incarnatum in China.

Plant Dis 2021 Mar 23. Epub 2021 Mar 23.

Shangqiu Normal University, Shangqiu 476000, Henan, P.R. ChinaShangqiu, China, 476000;

Pepper (Capsicum annuum L.), with annual production over 1 million tons, is ranked the first vegetable crop in Hainan Province, China. In December 2018, fruit rot of chili pepper , with yield loss of up to 15%, was found in 10 fields (12 hm2) in Yacheng (18°N, 109°E), Hainan Province, China. Read More

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Microtubule associated proteins and motors required for ectopic microtubule array formation in S. cerevisiae.

Genetics 2021 Mar 22. Epub 2021 Mar 22.

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

The mitotic spindle is resilient to perturbation due to the concerted, and sometimes redundant, action of motors and microtubule-associated proteins. Here we utilize an inducible ectopic microtubule nucleation site in the nucleus of Saccharomyces cerevisiae to study three necessary steps in the formation of a bipolar array: the recruitment of the γ-tubulin complex, nucleation and elongation of microtubules, and the organization of microtubules relative to each other. This novel tool, an Spc110 chimera, reveals previously unreported roles of the microtubule-associated proteins Stu2, Bim1, and Bik1, and the motors Vik1 and Kip3. Read More

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Orbit/CLASP determines centriole length by antagonising Klp10A in spermatocytes.

J Cell Sci 2021 Mar 26;134(6). Epub 2021 Mar 26.

Department of Insect Biomedical Research, Centre for Advanced Insect Research Promotion, Kyoto Institute of Technology, Kyoto 606-8585, Japan

After centrosome duplication, centrioles elongate before M phase. To identify genes required for this process and to understand the regulatory mechanism, we investigated the centrioles in premeiotic spermatocytes expressing fluorescently tagged centriolar proteins. We demonstrated that an essential microtubule polymerisation factor, Orbit (the CLASP orthologue, encoded by ), accumulated at the distal end of centrioles and was required for the elongation. Read More

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Stable kinetochore-microtubule attachments restrict MTOC position and spindle elongation in oocytes.

EMBO Rep 2021 04 3;22(4):e51400. Epub 2021 Mar 3.

Laboratory for Chromosome Segregation, RIKEN Center for Biosystems Dynamics Research (BDR), Kobe, Japan.

In mouse oocytes, acentriolar MTOCs functionally replace centrosomes and act as microtubule nucleation sites. Microtubules nucleated from MTOCs initially assemble into an unorganized ball-like structure, which then transforms into a bipolar spindle carrying MTOCs at its poles, a process called spindle bipolarization. In mouse oocytes, spindle bipolarization is promoted by kinetochores but the mechanism by which kinetochore-microtubule attachments contribute to spindle bipolarity remains unclear. Read More

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Cellular Pushing Forces during Mitosis Drive Mitotic Elongation in Collagen Gels.

Adv Sci (Weinh) 2021 Feb 4;8(4):2000403. Epub 2021 Jan 4.

Department of Mechanical Engineering Stanford University 418 Panama Mall Stanford CA 94305 USA.

Cell elongation along the division axis, or mitotic elongation, mediates proper segregation of chromosomes and other intracellular materials, and is required for completion of cell division. In three-dimensionally confining extracellular matrices, such as dense collagen gels, dividing cells must generate space to allow mitotic elongation to occur. In principle, cells can generate space for mitotic elongation during cell spreading, prior to mitosis, or via extracellular force generation or matrix degradation during mitosis. Read More

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February 2021

ANALYSIS OF FORMIN FUNCTIONS DURING CYTOKINESIS USING SPECIFIC INHIBITOR SMIFH2.

Plant Physiol 2021 Feb 23. Epub 2021 Feb 23.

Institute of Biological Chemistry, Washington State University, Pullman, WA, USA.

The phragmoplast separates daughter cells during cytokinesis by constructing the cell plate, which depends on interaction between cytoskeleton and membrane compartments. Proteins responsible for these interactions remain unknown, but formins can link cytoskeleton with membranes and several members of formin protein family localize to the cell plate. Progress in functional characterization of formins in cytokinesis is hindered by functional redundancies within the large formin gene family. Read More

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February 2021

Collective dynein transport of the nucleus by pulling on astral microtubules during Saccharomyces cerevisiae mitosis.

Yeast 2021 Jun 27;38(6):352-366. Epub 2021 Feb 27.

Division of Biology, IISER Pune, Dr. Homi Bhabha Road, Pune, Maharashtra, 411008, India.

Positioning the nucleus at the bud neck during Saccharomyces cerevisiae mitosis involves pulling forces of cytoplasmic dynein localized in the daughter cell. Although genetic analysis has revealed a complex network positioning the nucleus, quantification of the forces acting on the nucleus and the number of dyneins driving the process has remained difficult. To better understand the collective forces involved in nuclear positioning, we compare a model of dyneins-driven microtubule (MT) pulling, MT pushing, and cytoplasmic drag to experiments. Read More

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Regulation of Fibroblast Cell Polarity by Src Tyrosine Kinase.

Authors:
Kazuo Katoh

Biomedicines 2021 Feb 1;9(2). Epub 2021 Feb 1.

Laboratory of Human Anatomy and Cell Biology, Faculty of Health Sciences, Tsukuba University of Technology, Tsukuba-city, Ibaraki 305-8521, Japan.

Src protein tyrosine kinases (SFKs) are a family of nonreceptor tyrosine kinases that are localized beneath the plasma membrane and are activated during cell adhesion, migration, and elongation. Due to their involvement in the activation of signal transduction cascades, SFKs have been suggested to play important roles in the determination of cell polarity during cell extension and elongation. However, the mechanism underlying Src-mediated polarity formation remains unclear. Read More

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February 2021

CKAP2L Promotes Non-Small Cell Lung Cancer Progression through Regulation of Transcription Elongation.

Cancer Res 2021 Apr 20;81(7):1719-1731. Epub 2021 Jan 20.

Transcriptional Networks in Lung Cancer Group, Cancer Research UK Manchester Institute, University of Manchester, Manchester, United Kingdom.

Chromosomal instability (CIN) is a driver of clonal diversification and intratumor heterogeneity, providing genetic diversity that contributes to tumor progression. It is estimated that approximately 80% of solid cancers, including non-small cell lung cancer (NSCLC), exhibit features of CIN, which affects tumor growth and response to therapy. However, the molecular mechanisms connecting CIN to tumor progression are still poorly understood. Read More

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Dynein-dynactin segregate meiotic chromosomes in spermatocytes.

Development 2021 Feb 10;148(3). Epub 2021 Feb 10.

Instituto de Investigação e Inovação em Saúde - i3S, Universidade do Porto, 4200-135 Porto, Portugal

The microtubule motor cytoplasmic dynein 1 (dynein) and its essential activator dynactin have conserved roles in spindle assembly and positioning during female meiosis and mitosis, but their contribution to male meiosis remains poorly understood. Here, we characterize the G33S mutation in the dynactin subunit DNC-1, which corresponds to G59S in human p150 that causes motor neuron disease. In spermatocytes, delays spindle assembly and penetrantly inhibits anaphase spindle elongation in meiosis I, which prevents the segregation of homologous chromosomes. Read More

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February 2021

The phosphatase inhibitor Sds23 promotes symmetric spindle positioning in fission yeast.

Cytoskeleton (Hoboken) 2020 12 14;77(12):544-557. Epub 2020 Dec 14.

Department of Biochemistry and Cell Biology, The Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA.

A hallmark of cell division in eukaryotic cells is the formation and elongation of a microtubule (MT)-based mitotic spindle. Proper positioning of the spindle is critical to ensure equal segregation of the genetic material to the resulting daughter cells. Both the timing of spindle elongation and constriction of the actomyosin contractile ring must be precisely coordinated to prevent missegregation or damage to the genetic material during cellular division. Read More

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December 2020

Structure and Function of the Separase-Securin Complex.

Subcell Biochem 2021 ;96:217-232

Department of Biological Sciences, Columbia University, New York, NY, 10027, USA.

Separase is a large cysteine protease in eukaryotes and has crucial roles in many cellular processes, especially chromosome segregation during mitosis and meiosis, apoptosis, DNA damage repair, centrosome disengagement and duplication, spindle stabilization and elongation. It dissolves the cohesion between sister chromatids by cleaving one of the subunits of the cohesin ring for chromosome segregation. The activity of separase is tightly controlled at many levels, through direct binding of inhibitory proteins as well as posttranslational modification. Read More

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February 2021

A guide to plant TPX2-like and WAVE-DAMPENED2-like proteins.

J Exp Bot 2021 02;72(4):1034-1045

Plant Molecular Sciences Graduate Program, Washington State University, Pullman, WA, USA.

TPX2 proteins were first identified in vertebrates as a key mitotic spindle assembly factor. Subsequent studies demonstrated that TPX2 is an intricate protein, with functionally and structurally distinct domains and motifs including Aurora kinase-binding, importin-binding, central microtubule-binding, and C-terminal TPX2 conserved domain, among others. The first plant TPX2-like protein, WAVE-DAMPENED2, was identified in Arabidopsis as a dominant mutation responsible for reducing the waviness of roots grown on slanted agar plates. Read More

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February 2021

Loss of FZO1 gene results in changes of cell dynamics in fission yeast.

Int J Mol Med 2020 Dec 12;46(6):2194-2206. Epub 2020 Oct 12.

Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), College of Life Sciences, China West Normal University, Nanchong, Sichuan 637009, P.R. China.

Mitochondrial fission and fusion dynamics are critical cellular processes, and abnormalities in these processes are associated with severe human disorders, such as Beckwith‑Wiedemann syndrome, neurodegenerative diseases, Charcot‑Marie‑Tooth disease type 6, multiple symmetric lipomatosis and microcephaly. Fuzzy onions protein 1 (Fzo1p) regulates mitochondrial outer membrane fusion. In the present study, Schizosaccharomyces pombe (S. Read More

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December 2020

Evidence for anaphase pulling forces during C. elegans meiosis.

J Cell Biol 2020 12;219(12)

Department of Molecular and Cellular Biology, University of California, Davis, Davis, CA.

Anaphase chromosome movement is thought to be mediated by pulling forces generated by end-on attachment of microtubules to the outer face of kinetochores. However, it has been suggested that during C. elegans female meiosis, anaphase is mediated by a kinetochore-independent pushing mechanism with microtubules only attached to the inner face of segregating chromosomes. Read More

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December 2020

Ase1 domains dynamically slow anaphase spindle elongation and recruit Bim1 to the midzone.

Mol Biol Cell 2020 11 30;31(24):2733-2747. Epub 2020 Sep 30.

Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045.

How cells regulate microtubule cross-linking activity to control the rate and duration of spindle elongation during anaphase is poorly understood. In this study, we test the hypothesis that PRC1/Ase1 proteins use distinct microtubule-binding domains to control the spindle elongation rate. Using the budding yeast Ase1, we identify unique contributions for the spectrin and carboxy-terminal domains during different phases of spindle elongation. Read More

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November 2020

Stoichiometric interactions explain spindle dynamics and scaling across 100 million years of nematode evolution.

Elife 2020 09 23;9. Epub 2020 Sep 23.

Department of Molecular and Cellular Biology and School of Engineering and Applied Sciences, Harvard University, Cambridge, United States.

The spindle shows remarkable diversity, and changes in an integrated fashion, as cells vary over evolution. Here, we provide a mechanistic explanation for variations in the first mitotic spindle in nematodes. We used a combination of quantitative genetics and biophysics to rule out broad classes of models of the regulation of spindle length and dynamics, and to establish the importance of a balance of cortical pulling forces acting in different directions. Read More

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September 2020

Spermatogenesis in the inseminating African butterflyfish Pantodon buchholzi (Teleostei: Osteoglossiformes: Pantodontidae) with the revision of residual bodies formation.

J Fish Biol 2020 Nov 17;97(5):1491-1506. Epub 2020 Sep 17.

Department of Comparative Anatomy, Institute of Zoology and Biomedical Research, Jagiellonian University, Cracow, Poland.

The aim of this study was to analyse spermatogenesis in the African butterflyfish, Pantodon buchholzi, using transmission electron microscopy and scanning electron microscopy. P. buchholzi is the most basal teleost that exhibits insemination and produces a highly complex introsperm with the most elongate midpiece known in teleost fishes. Read More

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November 2020

The functions of kinesin and kinesin-related proteins in eukaryotes.

Cell Adh Migr 2020 12;14(1):139-152

State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences , Beijing, China.

Kinesins constitute a superfamily of ATP-driven microtubule motor enzymes that convert the chemical energy of ATP hydrolysis into mechanical work along microtubule tracks. Kinesins are found in all eukaryotic organisms and are essential to all eukaryotic cells, involved in diverse cellular functions such as microtubule dynamics and morphogenesis, chromosome segregation, spindle formation and elongation and transport of organelles. In this review, we explore recently reported functions of kinesins in eukaryotes and compare their specific cargoes in both plant and animal kingdoms to understand the possible roles of uncharacterized motors in a kingdom based on their reported functions in other kingdoms. Read More

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December 2020

AKAP350 enables p150glued /EB1 interaction at the spindle poles.

Biochimie 2020 Oct 22;177:127-131. Epub 2020 Aug 22.

Instituto de Fisiología Experimental, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario (UNR), 2000, Rosario, Argentina. Electronic address:

A-kinase anchoring protein 350 (AKAP350) is a centrosomal/Golgi scaffold protein, critical for the regulation of microtubule dynamics. AKAP350 recruits end-binding protein 1 (EB1) to the centrosome in mitotic cells, ensuring proper spindle orientation in epithelial cells. AKAP350 also interacts with p150, the main component of the dynactin complex. Read More

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October 2020

Wnt-controlled sphingolipids modulate Anthrax Toxin Receptor palmitoylation to regulate oriented mitosis in zebrafish.

Nat Commun 2020 07 3;11(1):3317. Epub 2020 Jul 3.

Department of Biochemistry and NCCR Chemical Biology, 30 Quai Ernest-Ansermet, 1211, Geneva 4, Switzerland.

Oriented cell division is a fundamental mechanism to control asymmetric stem cell division, neural tube elongation and body axis extension, among other processes. During zebrafish gastrulation, when the body axis extends, dorsal epiblast cells display divisions that are robustly oriented along the animal-vegetal embryonic axis. Here, we use a combination of lipidomics, metabolic tracer analysis and quantitative image analysis to show that sphingolipids mediate spindle positioning during oriented division of epiblast cells. Read More

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PP2A--B55γ counteracts Cdk1 and regulates proper spindle orientation through the cortical dynein adaptor NuMA.

J Cell Sci 2020 07 31;133(14). Epub 2020 Jul 31.

Department of Microbiology and Cell Biology, Indian Institute of Science, 560012 Bangalore, India

Proper orientation of the mitotic spindle is critical for accurate development and morphogenesis. In human cells, spindle orientation is regulated by the evolutionarily conserved protein NuMA, which interacts with dynein and enriches it at the cell cortex. Pulling forces generated by cortical dynein orient the mitotic spindle. Read More

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PP2A dephosphorylates Pds1 and inhibits spindle elongation in .

J Cell Sci 2020 07 29;133(14). Epub 2020 Jul 29.

Biology Department, Brooklyn College, The City University of New York, Brooklyn, NY 11238, USA

PP2A (the form of protein phosphatase 2A containing Cdc55) regulates cell cycle progression by reversing cyclin-dependent kinase (CDK)- and polo-like kinase (Cdc5)-dependent phosphorylation events. In , Cdk1 phosphorylates securin (Pds1), which facilitates Pds1 binding and inhibits separase (Esp1). During anaphase, Esp1 cleaves the cohesin subunit Scc1 and promotes spindle elongation. Read More

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