scholarly journals Gohta Goshima: Questing for answers on the mitotic spindle

2014 ◽  
Vol 206 (2) ◽  
pp. 148-149 ◽  
Author(s):  
Caitlin Sedwick
Keyword(s):  
Mitotic Spindle ◽  
Spindle Assembly ◽  
Microtubule Dynamics

Goshima studies spindle assembly and microtubule dynamics.

scholarly journals XKCM1: A Xenopus Kinesin-Related Protein That Regulates Microtubule Dynamics during Mitotic Spindle Assembly

Cell ◽  
1996 ◽  
Vol 84 (1) ◽  
pp. 37-47 ◽  
Author(s):  
Claire E Walczak ◽  
Timothy J Mitchison ◽  
Arshad Desai
Keyword(s):  
Mitotic Spindle ◽  
Spindle Assembly ◽  
Microtubule Dynamics ◽  
Related Protein ◽  
Mitotic Spindle Assembly

scholarly journals Thirty years of search and capture: The complex simplicity of mitotic spindle assembly

2015 ◽  
Vol 211 (6) ◽  
pp. 1103-1111 ◽  
Author(s):  
Rebecca Heald ◽  
Alexey Khodjakov
Keyword(s):  
Cell Division ◽  
Mitotic Spindle ◽  
Spindle Assembly ◽  
Microtubule Dynamics ◽  
Adaptive Changes ◽  
Bipolar Spindle ◽  
Chromosome Architecture ◽  
Self Assembling ◽  
Motor Activities ◽  
Mitotic Spindle Assembly

Cell division is enacted by a microtubule-based, self-assembling macromolecular machine known as the mitotic spindle. In 1986, Kirschner and Mitchison proposed that by undergoing dynamic cycles of growth and disassembly, microtubules search for chromosomes. Capture of microtubules by the kinetochores progressively connects chromosomes to the bipolar spindle. 30 years later, “search and capture” remains the cornerstone of spindle assembly. However, a variety of facilitating mechanisms such as regulation of microtubule dynamics by diffusible gradients, spatially selective motor activities, and adaptive changes in chromosome architecture have been discovered. We discuss how these mechanisms ensure that the spindle assembles rapidly and with a minimal number of errors.

scholarly journals Nup98 regulates bipolar spindle assembly through association with microtubules and opposition of MCAK

2011 ◽  
Vol 22 (5) ◽  
pp. 661-672 ◽  
Author(s):  
Marie K. Cross ◽  
Maureen A. Powers
Keyword(s):  
Nuclear Pore Complex ◽  
Mitotic Spindle ◽  
Spindle Assembly ◽  
Microtubule Dynamics ◽  
Nuclear Pore ◽  
Bipolar Spindle ◽  
Terminal Domain ◽  
C Terminus ◽  
Mitotic Spindle Assembly

During mitosis, the nuclear pore complex is disassembled and, increasingly, nucleoporins are proving to have mitotic functions when released from the pore. We find a contribution of the nucleoporin Nup98 to mitotic spindle assembly through regulation of microtubule dynamics. When added to Xenopus extract spindle assembly assays, the C-terminal domain of Nup98 stimulates uncontrolled growth of microtubules. Conversely, inhibition or depletion of Nup98 leads to formation of stable monopolar spindles. Spindle bipolarity is restored by addition of purified, recombinant Nup98 C-terminus. The minimal required region of Nup98 corresponds to a portion of the C-terminal domain lacking a previously characterized function. We show association between this region of the C-terminus of Nup98 and both Taxol-stabilized microtubules and the microtubule-depolymerizing mitotic centromere–associated kinesin (MCAK). Importantly, we demonstrate that this domain of Nup98 inhibits MCAK depolymerization activity in vitro. These data support a model in which Nup98 interacts with microtubules and antagonizes MCAK activity, thus promoting bipolar spindle assembly.

scholarly journals Dynamic microtubules are essential for efficient chromosome capture and biorientation in S. cerevisiae

2006 ◽  
Vol 175 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Baoying Huang ◽  
Tim C. Huffaker
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mitotic Spindle ◽  
Spindle Assembly Checkpoint ◽  
Direct Evidence ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Spindle Assembly ◽  
Spindle Pole ◽  
Microtubule Dynamics ◽  
Three Dimensional Space

Attachment of chromosomes to the mitotic spindle has been proposed to require dynamic microtubules that randomly search three-dimensional space and become stabilized upon capture by kinetochores. In this study, we test this model by examining chromosome capture in Saccharomyces cerevisiae mutants with attenuated microtubule dynamics. Although viable, these cells are slow to progress through mitosis. Preanaphase cells contain a high proportion of chromosomes that are attached to only one spindle pole and missegregate in the absence of the spindle assembly checkpoint. Measurement of the rates of chromosome capture and biorientation demonstrate that both are severely decreased in the mutants. These results provide direct evidence that dynamic microtubules are critical for efficient chromosome capture and biorientation and support the hypothesis that microtubule search and capture plays a central role in assembly of the mitotic spindle.

scholarly journals Pharmacologic inhibition of CDC25 phosphatases impairs interphase microtubule dynamics and mitotic spindle assembly

2007 ◽  
Vol 6 (1) ◽  
pp. 318-325 ◽  
Author(s):  
Martine Cazales ◽  
Rose Boutros ◽  
Marie-Christine Brezak ◽  
Sophie Chaumeron ◽  
Grégoire Prevost ◽  
...  
Keyword(s):  
Mitotic Spindle ◽  
Spindle Assembly ◽  
Microtubule Dynamics ◽  
Mitotic Spindle Assembly ◽  
Pharmacologic Inhibition

scholarly journals The impact of chromosomes and centrosomes on spindle assembly as observed in living cells.

1995 ◽  
Vol 129 (5) ◽  
pp. 1287-1300 ◽  
Author(s):  
D Zhang ◽  
R B Nicklas
Keyword(s):  
Spindle Assembly ◽  
Living Cells ◽  
Microtubule Dynamics ◽  
Specific Site ◽  
Polarization Microscopy ◽  
Spindle Microtubule ◽  
Single Chromosome ◽  
Bipolar Spindle ◽  
The Impact

We analyzed the role that chromosomes, kinetochores, and centrosomes play in spindle assembly in living grasshopper spermatocytes by reconstructing spindles lacking certain components. We used video-enhanced, polarization microscopy to distinguish the effect of each component on spindle microtubule dynamics and we discovered that both chromosomes and centrosomes make potent and very different contributions to the organization of the spindle. Remarkably, the position of a single chromosome can markedly affect the distribution of microtubules within a spindle or even alter the fate of spindle assembly. In an experimentally constructed spindle having only one chromosome, moving the chromosome to one of the two poles induces a dramatic assembly of microtubules at the nearer pole and a concomitant disassembly at the farther pole. So long as a spindle carries a single chromosome it will persist normally. A spindle will also persist even when all chromosomes are detached and then removed from the cell. If, however, a single chromosome remains in the cell but is detached from the spindle and kept in the cytoplasm, the spindle disassembles. One might expect the effect of chromosomes on spindle assembly to relate to a property of a specific site on each chromosome, perhaps the kinetochore. We have ruled out that possibility by showing that it is the size of chromosomes rather than the number of kinetochores that matters. Although chromosomes affect spindle assembly, they cannot organize a spindle in the absence of centrosomes. In contrast, centrosomes can organize a functional bipolar spindle in the absence of chromosomes. If both centrosomes and chromosomes are removed from the cell, the spindle quickly disappears.

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