• The polarity of the microtubules is important for cellular transport, as the motor proteins kinesin and dynein typically move preferentially in the "plus" and "minus" directions respectively, along a microtubule, allowing vesicles to be directed to or from the endoplasmic reticulum and Golgi apparatus. (wikipedia.org)
  • A family of microtubule-associated proteins (or 'MAPs' for short) bind to microtubules and assist in organising the filaments, but it is not clear how they work. (elifesciences.org)
  • The experiments also found that oMAP4 can create links between different microtubules and act as a brake to prevent the filaments being moved excessively by motor proteins. (elifesciences.org)
  • Instead, Ran and its associated proteins shift their focus from nuclear transport to the regulation of microtubule dynamics. (silverchair.com)
  • The PCM is an ordered lattice that anchors a large number of microtubule (MT)-associated proteins, many of which bear putative coiled-coil domains, a tertiary structure known to facilitate protein-protein interactions [ 4 ]. (biomedcentral.com)
  • In animals, the two most important types of MTOCs are 1) the basal bodies associated with cilia and flagella and 2) the centrosome associated with spindle formation. (wikipedia.org)
  • In epithelial cells, MTOCs also anchor and organize the microtubules that make up cilia. (wikipedia.org)
  • We investigated whether the formation of aggresomes affected key centrosome functions: its ability to organize the microtubule network and to promote cilia formation. (biorxiv.org)
  • The microtubule-organizing Centre (MTOC) is a structure found in eukaryotic cells from which microtubules emerge. (wikipedia.org)
  • They develop in a juxtanuclear position, adjacent to the centrosome, the microtubule organizing centre of the cell, and share some protein components. (biorxiv.org)
  • The juxtanuclear location of the aggresome is shared by the centrosome, the microtubule organising centre of the cell. (biorxiv.org)
  • Recent findings by several groups have shown that the GTP-bound form of Ran is necessary for the nucleation and organization of microtubule structures during M phase. (silverchair.com)
  • The MTOC is made up of a pair of centrioles at its center, and is surrounded by pericentriolar material (PCM) that is important for microtubule nucleation. (wikipedia.org)
  • Microtubules are anchored at the MTOC by their minus ends, while their plus ends continue to grow into the cell periphery. (wikipedia.org)
  • In yeasts and some algae, the MTOC is embedded into the nuclear envelope as a spindle pole body. (wikipedia.org)
  • In animal cells, centrosomes represent the major microtubule-organizing structures (MTOC). (biomedcentral.com)
  • Such dynamism is essential for assembling and positioning the bipolar spindle, searching for and docking with kinetochores, congressing and segregating chromosomes, and governing the spindle checkpoint [ 1 ]. (biomedcentral.com)
  • PIP4KIIγ accumulates at the spindle pole before anaphase, and is required for the assembly of functional bipolar spindles. (biomedcentral.com)
  • If the role of KMTs is to mediate forces between chromosomes and spindle poles, they need to somehow connect to the centrosomes. (nature.com)
  • A previous screen of a human kinase and phosphatase shRNA library to select genes that mediate arsenite induction of spindle abnormalities resulted in the identification of phosphatidylinositol-5-phosphate 4-kinase type-2 gamma (PIP4KIIγ), a phosphatidylinositol 4,5-bisphosphate (PIP2)-synthesizing enzyme. (biomedcentral.com)
  • Particularly for the Golgi apparatus, structures associated with the apparatus travel towards the minus end of a microtubule and aid in the overall structure and site of the Golgi in the cell. (wikipedia.org)
  • Centrosomes are the major microtubule organizing structures in vertebrate cells. (biomedcentral.com)
  • Our current results imply that PIP4KIIγ may restrain MT depolymerization at the spindle pole through attenuating PLK1-mediated activation of MCAK before anaphase onset. (biomedcentral.com)
  • Most notably, oMAP4 is required for paraxial microtubule organisation in muscle cells and prevents dynein- and kinesin-driven microtubule-microtubule sliding. (elifesciences.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)
  • The spindle microtubule (MT) exhibits highly regulated dynamic instability, with frequent polymerization and depolymerization occurring at both the plus and minus ends. (biomedcentral.com)
  • The precise regulations of pre-RC protein levels and assembly are effective ways to prevent reassembly of de novo MCM2-7 onto the replicated origins to re-license and re-replicate the genomic DNA in the subsequent phases of the same cell cycle ( Figure 1) . (intechopen.com)
  • In this study, we explored how PIP4KIIγ regulates the assembly of mitotic spindles. (biomedcentral.com)
  • Within the cells, microtubule-organizing centers can take on many different forms. (wikipedia.org)
  • Plant cells lack centrioles or spindle pole bodies except in their flagellate male gametes, and they are entirely absent in the conifers and flowering plants. (wikipedia.org)
  • We find that when aggresomes are present, neuronal cells are unable to organise their microtubule network. (biorxiv.org)
  • New microtubules are not nucleated and extended, and the cells fail to respond to polarity cues. (biorxiv.org)
  • The microtubules in cells that make smaller amounts of this protein were more disorganised, and these cells were unable to fuse with each other to form muscle cells. (elifesciences.org)
  • Microtubule-organizing centers function as the site where microtubule formation begins, as well as a location where free-ends of microtubules attract to. (wikipedia.org)
  • An array of microtubules can arrange themselves in a pinwheel structure to form the basal bodies, which can lead to the formation of microtubule arrays in the cytoplasm or the 9+2 axoneme. (wikipedia.org)
  • We propose a model in which the cooperation of dynein-mediated microtubule transport and oMAP4-mediated zippering of microtubules drives formation of a paraxial microtubule array that provides critical support for the polarisation and elongation of myotubes. (elifesciences.org)
  • used microscopy to observe the formation of the microtubule filaments in living myoblasts. (elifesciences.org)
  • Therefore, the next challenge is to understand how other processes-such as the selective stabilisation of some microtubules and the movement of cell materials along the microtubules-cooperate to control muscle fibre formation. (elifesciences.org)
  • In addition, coordination of MT polymerization/depolymerization at both ends to maintain the size and shape of mitotic spindles is also critical for the proper formation and function of the mitotic spindle. (biomedcentral.com)
  • In toto , our results show that the connection between centrosomes and chromosomes is mediated by an anchoring into the entire spindle network and that any direct connections through KMTs are few and likely very transient. (nature.com)
  • 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)
  • 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)
  • In this chapter, we mainly discuss the coordination regulations between DNA replication initiation and other cell cycle events that ensure genomic integrity. (intechopen.com)
  • A related question is the site of KMT nucleation. (nature.com)
  • In this study, we identify a previously uncharacterised isoform of microtubule-associated protein MAP4, oMAP4, as a microtubule organising factor that is crucial for myogenesis. (elifesciences.org)
  • The similarities in BPs and Wnt signaling regulation regarding PPP4C support the intrinsic link between tumorigenesis and early embryogenesis. (bvsalud.org)