Search Results
Results 101 - 150 of 1052
1 2 3 4 5 6 7 8 9 10 >
Brito Ilana L - - 2010
Lrs4 and Csm1, components of the monopolin complex, localize to the rDNA where they regulate rDNA maintenance and segregation. During meiosis, the complex also associates with kinetochores to bring about sister kinetochore co-orientation, an essential aspect of meiosis I chromosome segregation. We show here that the Lrs4-Csm1 complex associates with ...
Shimogawa Michelle M MM Department of Biochemistry, University of Washington, Seattle, WA, - - 2010
Kinetochore attachment to the ends of dynamic microtubules is a conserved feature of mitotic spindle organization that is thought to be critical for proper chromosome segregation. Although kinetochores have been described to transition from lateral to end-on attachments, the phase of lateral attachment has been difficult to study in yeast ...
Han Xue - - 2010
Kinetochores link microtubules to DNA and provide force critical for chromosome segregation in mitosis. New data show that kinetochores are not necessary for acentrosomal meiotic chromosome segregation in Caenorhabditis elegans. Instead, CLS-2 (CLASP) generates a mid-zone bundle of microtubules that are suggested to act in pushing the chromosomes apart.
Dumont Julien J Ludwig Institute for Cancer Research, Department of Cellular & Molecular Medicine, University of California, San Diego, La Jolla, CA 92093-0653, - - 2010
Although assembly of acentrosomal meiotic spindles has been extensively studied, little is known about the segregation of chromosomes on these spindles. Here, we show in Caenorhabditis elegans oocytes that the kinetochore protein, KNL-1, directs assembly of meiotic kinetochores that orient chromosomes. However, in contrast to mitosis, chromosome separation during meiotic ...
Mukhopadhyay Debaditya - - 2010
Genetic evidence suggests that conjugation of Small Ubiquitin-like Modifier proteins (SUMOs) plays an important role in kinetochore function, although the mechanism underlying these observations are poorly defined. We found that depletion of the SUMO protease SENP6 from HeLa cells causes chromosome misalignment, prolonged mitotic arrest and chromosome missegregation. Many inner ...
Gascoigne Karen E KE Whitehead Institute for Biomedical Research, and Department of Biology, Massachusetts Institute of Technology, Nine Cambridge Center, Cambridge, MA 02142, United States. - - 2011
Accurate chromosome segregation requires the interaction of chromosomes with the microtubules from the mitotic spindle. This interaction is mediated by the macro-molecular kinetochore complex, which assembles only at the centromeric region of each chromosome. However, how this site is specified and how assembly of the kinetochore structure is regulated in ...
Hewitt Laura L Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, England, - - 2010
Mps1 is an essential component of the spindle assembly checkpoint. In this study, we describe a novel Mps1 inhibitor, AZ3146, and use it to probe the role of Mps1's catalytic activity during mitosis. When Mps1 is inhibited before mitotic entry, subsequent recruitment of Mad1 and Mad2 to kinetochores is abolished. ...
Vázquez-Novelle María Dolores - - 2010
The mitotic checkpoint monitors the attachment of kinetochores to microtubules and delays anaphase onset until all sister kinetochores have become attached to opposite poles [1, 2]. Correct bipolar attachment leads to kinetochore deformation and tension and satisfies the checkpoint [3-6]. What prevents mitotic checkpoint reactivation when sister centromeres are split ...
Wargacki Megan M MM Department of Biochemistry, University of Washington, Seattle, WA, - - 2010
In Saccharomyces cerevisiae, chromosome congression clusters kinetochores on either side of the spindle equator at metaphase. Many organisms require one or more kinesin-8 molecular motors to achieve chromosome alignment. The yeast kinesin-8, Kip3, has been well studied in vitro but a role in chromosome congression has not been reported. We ...
Stukenberg P Todd PT Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, Charlottesville, VA 22908, USA. - - 2010
When it comes to microtubules, kinetochores leave nothing to chance. Recent studies have provided insight into an amazingly choreographed dance between the proteins in the kinetochore and their substrate and power source--the microtubule.
Weber Stephanie C - - 2010
Tracking of fluorescently labeled chromosomal loci in live bacterial cells reveals a robust scaling of the mean square displacement (MSD) as τ(0.39). We propose that the observed motion arises from relaxation of the Rouse modes of the DNA polymer within the viscoelastic environment of the cytoplasm. The time-averaged and ensemble-averaged ...
Zhang Qing-Hua - - 2010
Spindly was first identified in Drosophila; its homologues are termed SPDL-1 in Caenorhabditis elegans and Hs Spindly/hSpindly in humans. In all species, Spindly and its homologues function by recruiting dynein to kinetochores and silencing SAC in mitosis of somatic cells. Depletion of Spindly causes an extensive metaphase arrest during somatic ...
Illingworth Crista C University College London Institute for Women's Health, 86-96 Chenies Mews, London WC1E6HX, - - 2010
Errors in chromosome segregation in mammalian oocytes lead to aneuploid eggs that are developmentally compromised. In mitotic cells, mitotic centromere associated kinesin (MCAK; KIF2C) prevents chromosome segregation errors by detaching incorrect microtubule-kinetochore interactions. Here, we examine whether MCAK is involved in spindle function in mouse oocyte meiosis I, and whether ...
Gassmann Reto R Ludwig Institute for Cancer Research/Department of Cellular and Molecular Medicine, University of California at San Diego, La Jolla, California 92093, - - 2010
The spindle checkpoint generates a "wait anaphase" signal at unattached kinetochores to prevent premature anaphase onset. Kinetochore-localized dynein is thought to silence the checkpoint by transporting checkpoint proteins from microtubule-attached kinetochores to spindle poles. Throughout metazoans, dynein recruitment to kinetochores requires the protein Spindly. Here, we identify a conserved motif ...
Barisic Marin - - 2010
Spindly recruits a fraction of cytoplasmic dynein to kinetochores for poleward movement of chromosomes and control of mitotic checkpoint signaling. Here we show that human Spindly is a cell cycle-regulated mitotic phosphoprotein that interacts with the Rod/ZW10/Zwilch (RZZ) complex. The kinetochore levels of Spindly are regulated by microtubule attachment and ...
Bieling Peter - - 2010
During cell division, correct positioning of chromosomes in mitotic and meiotic spindles depends on interactions of microtubules with kinetochores and, especially in higher eukaryotes, with the chromosome arms [1, 2]. Chromokinesins, highly concentrated on mitotic and meiotic chromatin, are thought to actively push the chromosome arms toward the spindle center, ...
Becker Markus - - 2010
During mitosis, the chromosomal passenger complex (CPC) comprising the Aurora B kinase, INCENP, survivin and borealin is essential for correcting non-bipolar chromosome attachments and for cytokinesis. In addition, the CPC might fullfil a role in the mitotic spindle assembly checkpoint (SAC), but this activity might be related to its role ...
Maia André F - - 2010
Error-free chromosome segregation requires that all chromosomes biorient on the mitotic spindle. The motor protein Centromere-associated protein E (CENP-E) facilitates chromosome congression by mediating the lateral sliding of sister chromatids along existing K-fibers, while the mitotic kinase Aurora B detaches kinetochore-microtubule interactions that are not bioriented. Whether these activities cooperate ...
Tanenbaum Marvin E - - 2010
During mitosis, all chromosomes must attach to microtubules of the mitotic spindle to ensure correct chromosome segregation. Microtubule attachment occurs at specialized structures at the centromeric region of chromosomes, called kinetochores. These kinetochores can generate microtubule attachments through capture of centrosome-derived microtubules, but in addition, they can generate microtubules themselves, ...
Kops Geert J P L - - 2010
Genomic stability requires error-free chromosome segregation during mitosis. Chromosome congression to the spindle equator precedes chromosome segregation in anaphase and is a hallmark of metazoan mitosis. Here we review the current knowledge and concepts on the processes that underlie chromosome congression, including initial attachment to spindle microtubules, biorientation, and movements, ...
Maresca Thomas J - - 2010
Recent high-resolution studies of kinetochore structure have transformed the way researchers think about this crucial macro-molecular complex, which is essential for ensuring chromosome segregation occurs faithfully during cell division. Kinetochores mediate the interaction between chromosomes and the plus-ends of dynamic spindle microtubules and control the timing of anaphase onset by ...
Kiyomitsu Tomomi - - 2010
Centromeric DNA forms two structures on the mitotic chromosome: the kinetochore, which interacts with kinetochore microtubules, and the inner centromere, which connects sister kinetochores. The assembly of the inner centromere is poorly understood. In this study, we show that the human Mis14 (hMis14; also called hNsl1 and DC8) subunit of ...
Amaro Ana C AC Institute of Biochemistry, Eidgenössische Technische Hochschule (ETH) Zurich, CH-8093 Zurich, - - 2010
Chromosome segregation in metazoans requires the alignment of sister kinetochores on the metaphase plate. During chromosome alignment, bioriented kinetochores move chromosomes by regulating the plus-end dynamics of the attached microtubules. The bundles of kinetochore-bound microtubules alternate between growth and shrinkage, leading to regular oscillations along the spindle axis. However, the ...
Jaqaman Khuloud K Marine Biological Laboratory, Woods Hole, MA 02543, - - 2010
During mitosis in most eukaryotic cells, chromosomes align and form a metaphase plate halfway between the spindle poles, about which they exhibit oscillatory movement. These movements are accompanied by changes in the distance between sister kinetochores, commonly referred to as breathing. We developed a live cell imaging assay combined with ...
Oh Hyun Jung - - 2010
The establishment and maintenance of proper attachment of kinetochores to microtubules are required to prevent chromosome missegregation and consequent chromosomal instability and tumorigenesis. Although MST1 (mammalian sterile 20-like kinase 1) has been implicated in many aspects of cell cycle regulation and tumor suppression [1], its precise mechanism of action has ...
Savoian Matthew S MS University of Cambridge, Department of Genetics, Cambridge, CB2 3EH, UK. - - 2010
The kinesin-8 proteins are a family of microtubule-depolymerising motor molecules, which, despite their highly conserved roles in chromosome alignment and spindle dynamics, remain poorly characterised. Here, we report that the Drosophila kinesin-8 protein, Klp67A, exists in two spatially and functionally separable metaphase pools: at kinetochores and along the spindle. Fixed ...
Cai Xiwen - - 2010
Unreductional meiotic cell division (UMCD) generates unreduced gametes and leads to polyploidy. The tetraploid wheat "Langdon" (LDN) undergoes normal meiosis, but its polyhaploid undergoes UMCD. Here, we found that sister kinetochores oriented syntelically at meiosis I in LDN, but amphitelically in LDN polyhaploid and the interspecific hybrid of LDN with ...
Walczak Claire E CE Medical Sciences Program, Indiana University, Myers Hall 262, 915 East 3rd Street, Bloomington, Indiana, 47405, USA. - - 2010
For over a century, scientists have strived to understand the mechanisms that govern the accurate segregation of chromosomes during mitosis. The most intriguing feature of this process, which is particularly prominent in higher eukaryotes, is the complex behaviour exhibited by the chromosomes. This behaviour is based on specific and highly ...
Shtylla Blerta - - 2010
During mitosis chromosomes use a complex network of dynamic microtubules to find the cell equator in preparation for division signals. The roles of cellular chemical signals in mechanisms driving mitotic chromosomal movements are not well understood. In this paper we propose a mathematical model of this process which incorporates a ...
Bader Jason R JR Department of Biological Sciences, University of Notre Dame, Galvin Life Sciences Center, Notre Dame, IN 46556, United - - 2010
Kinetochores have been proposed to play multiple roles in mitotic chromosome alignment, including initial microtubule (MT) capture, monitoring MT attachments, prometaphase and anaphase chromosome movement and tension generation at metaphase. In addition, kinetochores are essential components of the spindle assembly checkpoint (SAC), and couple chromosome alignment with SAC silencing at ...
Goldstone Sherilyn - - 2010
The plus-end microtubule binding proteins (+TIPs) play an important role in the regulation of microtubule stability and cell polarity during interphase. In S. pombe, the CLIP-170 like protein Tip1, together with the kinesin Tea2, moves along the microtubules towards their plus ends. Tip1 also requires the EB1 homolog Mal3 to ...
DeLuca Jennifer G JG Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, Colorado 80523, - - 2010
Mitosis is the process by which a cell divides its genetic material equally into two daughter cells. Successful division requires that the two identical sister chromatids of a mitotic chromosome attach to the plus-ends of spindle microtubules (MTs) via their kinetochores, which are large protein structures built on centromeric DNA. ...
Liu Xue-Song XS Department of Medical Genetics, E-Institutes of Shanghai Universities, Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, - - 2010
Chromosomal instability during cell division frequently causes cell death or malignant transformation. Orderly chromosome congression at the metaphase plate, a paramount process to vertebrate mitosis and meiosis, is controlled by a number of molecular regulators, including kinesins. Kinesin-8 (Kif18A) functions to control mitotic chromosome alignment at the mid-zone by negative ...
Gestaut Daniel R DR Department of Biochemistry, University of Washington, Seattle, Washington 98195, - - 2010
Kinetochores are multifunctional supercomplexes that link chromosomes to dynamic microtubule tips. Groups of proteins from the kinetochore are arranged into distinct subcomplexes that copurify under stringent conditions and cause similar phenotypes when mutated. By coexpressing all the components of a given subcomplex from a polycistronic plasmid in bacteria, many laboratories ...
Platani Melpomeni - - 2009
The human Nup107-160 nucleoporin complex plays a major role in formation of the nuclear pore complex and is localized to kinetochores in mitosis. Here we report that Seh1, a component of the Nup107-160 complex, functions in chromosome alignment and segregation by regulating the centromeric localization of Aurora B and other ...
Khodjakov Alexey A Wadsworth Center, Albany, NY 12201-0509, USA. - - 2009
Recent studies reveal that the precise regulation of microtubule dynamics is essential for an error-free mitosis. Kinetochore microtubule attachments that are too stable increase the rate of chromosome mis-segregation, a leading cause of chromosomal instability in tumors.
Nogales Eva - - 2009
Faithful segregation of genetic material during cell division requires the dynamic but robust attachment of chromosomes to spindle microtubules during all stages of mitosis. This regulated attachment occurs at kinetochores, which are complex protein organelles that are essential for cell survival and genome integrity. In budding yeast, in which a ...
Bakhoum Samuel F SF Department of Biochemistry, Dartmouth Medical School, Hanover, NH 03755, - - 2009
The persistent malattachment of microtubules to chromosomes at kinetochores is a major mechanism of chromosomal instability (CIN) [1, 2]. In normal diploid cells, malattachments arise spontaneously and are efficiently corrected to preserve genomic stability [3]. However, it is unknown whether cancer cells with CIN possess the ability to efficiently correct ...
Nezi Luigi - - 2009
The spindle assembly checkpoint (SAC) is a feedback control system that monitors the state of kinetochore/microtubule attachment during mitosis and halts cell cycle progression until all chromosomes are properly aligned at the metaphase plate. The state of chromosome-microtubule attachment is implicated as a crucial factor in the checkpoint response. On ...
Bucciarelli Elisabetta - - 2009
In centrosome-containing cells, spindle assembly relies on microtubules (MTs) nucleated from both centrosomes and chromosomes. Recent work has suggested that additional spindle MTs can be nucleated by gamma-tubulin ring complexes (gamma-TuRCs) that associate laterally with preexisting spindle MTs, leading to spindle amplification. It has been proposed that in Drosophila S2 ...
Claycomb Julie M JM Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01606, - - 2009
RNAi-related pathways regulate diverse processes, from developmental timing to transposon silencing. Here, we show that in C. elegans the Argonaute CSR-1, the RNA-dependent RNA polymerase EGO-1, the Dicer-related helicase DRH-3, and the Tudor-domain protein EKL-1 localize to chromosomes and are required for proper chromosome segregation. In the absence of these ...
Rath Uttama - - 2009
Chromosome movements are linked to the active depolymerization of spindle microtubule (MT) ends. Here we identify the kinesin-13 family member, KLP59D, as a novel and uniquely important regulator of spindle MT dynamics and chromosome motility in Drosophila somatic cells. During prometaphase and metaphase, depletion of KLP59D, which targets to centrosomes ...
Maffini Stefano S Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, - - 2009
Efficient chromosome segregation during mitosis relies on the coordinated activity of molecular motors with proteins that regulate kinetochore attachments to dynamic spindle microtubules [1]. CLASPs are conserved kinetochore- and microtubule-associated proteins encoded by two paralog genes, clasp1 and clasp2, and have been previously implicated in the regulation of kinetochore microtubule ...
Kiermaier Eva - - 2009
Kinetochores are large multiprotein complexes that mediate chromosome segregation in all eukaryotes by dynamically connecting specialized chromosome regions, termed centromeres, to the plus-ends of spindle microtubules. Even the relatively simple kinetochores of the budding yeast Saccharomyces cerevisiae consist of more than 80 proteins, making analysis of their respective roles a ...
Li Xuexian - - 2009
During meiosis I the genome is reduced to the haploid content by a coordinated reductional division event. Homologous chromosomes align, recombine and segregate while the sister chromatids co-orient and move to the same pole. Several data suggest that sister kinetochores co-orient early in metaphase I and that sister chromatid cohesion ...
Lacefield Soni S Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, - - 2009
Accurate chromosome segregation depends on the kinetochore, which is the complex of proteins that link microtubules to centromeric DNA. The kinetochore of the budding yeast Saccharomyces cerevisiae consists of more than 80 proteins assembled on a 125-bp region of DNA. We studied the assembly and function of kinetochore components by ...
Huang Ying Y Department of Environmental Medicine and Pharmacology, New York University School of Medicine, Tuxedo, NY, - - 2009
KIF18A, a molecular motor, is an essential component in the regulation of orderly chromosome congression by attenuation of the kinetochore oscillation amplitude at the midzone during mitosis in vertebrate cells. Here we report that KIF18A depletion resulted in mitotic arrest which was accompanied by the presence of unaligned chromosomes in ...
Windecker Hanna - - 2009
The eukaryotic spindle assembly checkpoint (SAC) delays anaphase in the presence of chromosome attachment errors. Bub3 has been reported to be required for SAC activity in all eukaryotes examined so far. We find that Bub3, unlike its binding partner Bub1, is not essential for the SAC in fission yeast. As ...
Cardinale Stefano S Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR, United - - 2009
We previously used a human artificial chromosome (HAC) with a synthetic kinetochore that could be targeted with chromatin modifiers fused to tetracycline repressor to show that targeting of the transcriptional repressor tTS within kinetochore chromatin disrupts kinetochore structure and function. Here we show that the transcriptional corepressor KAP1, a downstream ...
Daum John R JR Cell Cycle and Cancer Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104, - - 2009
The mitotic spindle checkpoint monitors proper bipolar attachment of chromosomes to the mitotic spindle. Previously, depletion of the novel kinetochore complex Ska1/Ska2 was found to induce a metaphase delay. By using bioinformatics, we identified C13orf3, predicted to associate with kinetochores. Recently, three laboratories independently indentified C13orf3 as an additional Ska ...
1 2 3 4 5 6 7 8 9 10 >