• Indeed, that such forces exist in C. elegans is evidenced by the maintenance of half-spindle lengths throughout mitosis 5 and in many perturbations experiments. (nature.com)
  • During mitosis, microtubules in the spindle turn over continuously. (bvsalud.org)
  • When centrosomes fail to recruit γ-tubulin complexes, they still nucleate microtubules via the TOG domain protein Mini-spindles (Msps), but these microtubules have different dynamic properties. (bvsalud.org)
  • At spindle poles, where microtubule minus ends are concentrated, microtubule nucleation and depolymerization, the latter required for poleward microtubule flux, happen side by side. (bvsalud.org)
  • Together, these results provide insight into the molecular mechanisms by which a minimal protein module coordinates microtubule nucleation and depolymerization at spindle poles consistent with their role in poleward microtubule flux. (bvsalud.org)
  • Here we combine the first large-scale serial electron tomography of whole mitotic spindles in early C. elegans embryos with live-cell imaging to reconstruct all microtubules in 3D and identify their plus- and minus-ends. (nature.com)
  • Indeed, by quantitatively analysing several models of microtubule growth, we conclude that minus-ends of KMTs have selectively detached and depolymerized from the centrosome. (nature.com)
  • In Drosophila, Spindle defective-2 (Spd-2) and Centrosomin (Cnn) redundantly recruit γ-tubulin complexes to mitotic centrosomes. (bvsalud.org)
  • These data support a model in which Tum/RacGAP, via its interaction with Pbl, provides a critical link between the anaphase microtubule spindle and cytokinetic furrow formation in Drosophila cells. (biologists.com)
  • Together with dynactin, dynein regulates centrosomal orientation to establish and maintain cell polarity, controls focal adhesion turnover and anchors microtubules at the leading edge. (biologists.com)
  • Recently an actin-like protein has been found in the gram-positive bacterium Bacillus thuringiensis, which forms a microtubule-like structure called a nanotubule, involved in plasmid segregation. (wikipedia.org)
  • There are many proteins that bind to microtubules, including the motor proteins dynein and kinesin, microtubule-severing proteins like katanin, and other proteins important for regulating microtubule dynamics. (wikipedia.org)
  • In vitro assays for microtubule motor proteins such as dynein and kinesin are researched by fluorescently tagging a microtubule and fixing either the microtubule or motor proteins to a microscope slide, then visualizing the slide with video-enhanced microscopy to record the travel of the motor proteins. (wikipedia.org)
  • Dynein is the sole processive minus-end-directed microtubule motor found in animals. (biologists.com)
  • Microtubules have a distinct polarity that is critical for their biological function. (wikipedia.org)
  • The protofilaments bundle parallel to one another with the same polarity, so, in a microtubule, there is one end, the (+) end, with only β-subunits exposed, while the other end, the (−) end, has only α-subunits exposed. (wikipedia.org)
  • The formation and organization of the primary cilium are highly associated with cell polarity proteins, such as the apical polarity protein CRB3. (bvsalud.org)
  • Instead, Ran and its associated proteins shift their focus from nuclear transport to the regulation of microtubule dynamics. (silverchair.com)
  • Microtubules play an important role in a number of cellular processes. (wikipedia.org)
  • Tubulin and microtubule-mediated processes, like cell locomotion, were seen by early microscopists, like Leeuwenhoek (1677). (wikipedia.org)
  • Consequently, some microtubule processes can be determined by kymograph. (wikipedia.org)
  • How these seemingly antagonistic processes of nucleation and depolymerization are coordinated is not understood. (bvsalud.org)
  • Plant cells lack centrosomes and instead utilize acentrosomal microtubule organizing centers (MTOCs) to rapidly increase the number of microtubules at the onset of spindle assembly. (bvsalud.org)
  • We classify them as kinetochore (KMTs), spindle (SMTs) or astral microtubules (AMTs) according to their positions, and quantify distinct properties of each class. (nature.com)
  • There are two distinct types of interactions that can occur between the subunits of lateral protofilaments within the microtubule called the A-type and B-type lattices. (wikipedia.org)
  • Typically, microtubules are formed by the parallel association of thirteen protofilaments, although microtubules composed of fewer or more protofilaments have been observed in various species as well as in vitro. (wikipedia.org)
  • In this paper, we set out to identify the cytoskeletal ultrastructure in C. elegans mitotic spindles that underlies this function, and how this ultrastructure is generated, using a combination of large-scale electron tomography, light microscopy and mathematical modelling. (nature.com)
  • Although the positioning signal is likely to be transmitted via the anaphase microtubule array to the cell cortex, exactly how the microtubule array determines the site of contractile ring formation remains unresolved. (biologists.com)
  • The primary cilium plays important roles in regulating cell differentiation, signal transduction, and tissue organization. (bvsalud.org)
  • The GAP activity of Tum is required for cytokinesis: in its absence cytokinesis fails early even though Tum is present on microtubules at the cell equator where the furrow should form. (biologists.com)
  • Disruption of the Pebble-interacting domain leaves Tum localised to the cell equator on cortically associated microtubules, again with no evidence of furrowing. (biologists.com)
  • While our light microscopy and mutant studies show that microtubules are nucleated from the centrosomes, we find only a few KMTs directly connected to the centrosomes. (nature.com)
  • A related question is the site of KMT nucleation. (nature.com)
  • We find that the spindle pole-localized kinesin-13 KIF2A is a microtubule minus-end depolymerase, in contrast to its paralog MCAK. (bvsalud.org)
  • They also suggest that the dynamic properties of microtubules are influenced by how they are nucleated. (bvsalud.org)
  • Microtubules are nucleated and organized by microtubule-organizing centres, such as the centrosome found in the center of many animal cells or the basal bodies of cilia and flagella, or the spindle pole bodies found in most fungi. (wikipedia.org)
  • Our data, therefore, help explain the dispensability of the GCP4/5/4/6 core and highlight the robustness of centrosomes as microtubule organizing centers. (bvsalud.org)