• They are formed by the polymerization of a dimer of two globular proteins, alpha and beta tubulin into protofilaments that can then associate laterally to form a hollow tube, the microtubule. (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)
  • This allows the movement of the motor proteins along the microtubule or the microtubule moving across the motor proteins. (wikipedia.org)
  • Non-collagenous proteins could be involved in the nucleation of calcium- and phosphate crystals (hydroxyapatite) and may also control the initial growth and orientation of the ionic nucleus. (intelligentdental.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)
  • While plants employ some evolutionarily conserved proteins to regulate spindle morphogenesis and remodeling, many essential spindle assembly factors found in vertebrates are either missing or not required for producing the plant bipolar microtubule array. (nsf.gov)
  • It is intriguing what proteins are associated with plant‐specific MTOC s and how plant cells activate or inactivate MT nucleation activities in spatiotemporally regulated manners. (nsf.gov)
  • Rho GTPase effectors are a large group of proteins and include actin nucleation promoting molecules, adaptors, as well as kinases. (biomedcentral.com)
  • A class of proteins involved in the transport of molecules via TRANSPORT VESICLES. (lookformedical.com)
  • The outer surface of these vesicles are covered with a lattice-like network of coat proteins, such as CLATHRIN, coat protein complex proteins, or CAVEOLINS. (lookformedical.com)
  • A network of membrane compartments, located at the cytoplasmic side of the GOLGI APPARATUS, where proteins and lipids are sorted for transport to various locations in the cell or cell membrane. (lookformedical.com)
  • A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. (lookformedical.com)
  • At the cell equator, these factors stimulate the recruitment of formins which in turn results in the nucleation of actin filaments as well as myosin localization. (microscopemaster.com)
  • Unlike the globular units of microtubules and actin filaments, intermediate filaments are themselves constructed from filamentous sub-units, and confer strength as well as stress resistance to the cell[ 10 ]. (biorxiv.org)
  • Along with GIT1, positively regulates microtubule nucleation during interphase (PubMed:27012601). (icr.ac.uk)
  • Dynamin 2 also clings to microtubules of the mitotic spindle, and the team next wants to determine whether the protein regulates microtubule dynamics during the cell cycle. (rupress.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)
  • The mitotic spindle is a dynamic microtubule-based apparatus that ensures the segregation of chromosomes during cell division. (nature.com)
  • Remarkably, despite the high turnover of microtubules throughout mitosis 2 , the spindle maintains its bipolar structure with the chromosomes at its center and two poles that are separated by the plane of cell division. (nature.com)
  • Tubulin and microtubule-mediated processes, like cell locomotion, were seen by early microscopists, like Leeuwenhoek (1677). (wikipedia.org)
  • In eukaryotes, microtubules are long, hollow cylinders made up of polymerized α- and β-tubulin dimers. (wikipedia.org)
  • These α/β-tubulin dimers polymerize end-to-end into linear protofilaments that associate laterally to form a single microtubule, which can then be extended by the addition of more α/β-tubulin dimers. (wikipedia.org)
  • MT ‐dependent MT nucleation is particularly noticeable in plant cells because it accounts for the primary source of MT generation for assembling spindle, phragmoplast, and cortical arrays when the γ‐tubulin ring complex is anchored and activated by the augmin complex. (nsf.gov)
  • Microtubules, the cytoskeletal component with the widest cross-section at about 25nm in diameter, are hollow tubes consisting of repeated α - and β -tubulin sub-units[ 6 ]. (biorxiv.org)
  • 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)
  • Centrosomes are the major microtubule organizing structures in vertebrate cells. (biomedcentral.com)
  • In animal cells, centrosomes represent the major microtubule-organizing structures (MTOC). (biomedcentral.com)
  • In the meiosis of many species, the process of chromosome segregation requires that bipolar spindles be formed without the aid of dedicated microtubule organizing centers, such as centrosomes. (nsf.gov)
  • 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)
  • The researchers also found that blocking normal dynamin 2 with RNAi had the same effect as the mutation, confirming that one of dynamin 2's functions is to promote microtubule turnover. (rupress.org)
  • Chemical synapses release synaptic vesicles (SVs) at specialized presynaptic membranes, so-called active zones (AZs), which are characterized by electron-dense structures, reflecting the presence of extended molecular protein scaffolds. (sdbonline.org)
  • A molecular understanding of membrane traffic has broad implications for our understanding of growth control in cancer, receptor trafficking errors in heart disease, regulation of insulin secretion in diabetes and synaptic vesicle biogenesis and transport in neurological disorders. (stanford.edu)
  • Under physiological conditions, aSyn is considered to be a pre-synaptic protein [ 37 ] that associates with vesicles and membranes [ 11 ]. (biomedcentral.com)
  • Cytoskeletal microtubules ( MT s) have a multitude of functions including intracellular distribution of molecules and organelles, cell morphogenesis, as well as segregation of the genetic material and separation of the cytoplasm during cell division among eukaryotic organisms. (nsf.gov)
  • 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)
  • A mutant protein makes the microtubules too stable to perform their jobs, the researchers find. (rupress.org)
  • One of these mutations leads to production of faulty dynamin 2, a protein that is crucial for endocytosis but also latches onto microtubules. (rupress.org)
  • The exact function of aSyn remains unclear, but it is known to be associated with vesicles and membranes, and to have an impact on important cellular functions such as intracellular trafficking and protein degradation systems, leading to cellular pathologies that can be readily studied in cell-based models. (biomedcentral.com)
  • The main structural coat protein of COATED VESICLES which play a key role in the intracellular transport between membranous organelles. (lookformedical.com)
  • The outer surface of these vesicles is covered with a lattice-like network of the protein CLATHRIN. (lookformedical.com)
  • An adaptor protein complex primarily involved in the formation of clathrin-related endocytotic vesicles (ENDOSOMES) at the CELL MEMBRANE. (lookformedical.com)
  • In contrast to well-studied fungal and animal cells, plant cells assemble bipolar spindles that exhibit a great deal of plasticity in the absence of structurally defined microtubule-organizing centers like the centrosome. (nsf.gov)
  • They provide platforms for intracellular transport and are involved in a variety of cellular processes, including the movement of secretory vesicles, organelles, and intracellular macromolecular assemblies. (wikipedia.org)
  • They play a role in the intracellular transport of molecules contained within membrane vesicles. (lookformedical.com)
  • Consequently, some microtubule processes can be determined by kymograph. (wikipedia.org)
  • In higher plants, microtubule organizing centers (centrosome) is absent. (microscopemaster.com)
  • Although many key factors contributing to MT nucleation and organization are well conserved in different kingdoms, the centrosome, representing the most prominent microtubule organizing centers ( MTOC s), disappeared during plant evolution as angiosperms lack the structure. (nsf.gov)
  • 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)
  • Plant spindle assembly initiates with microtubule nucleation on the nuclear envelope followed by bipolarization into the prophase spindle. (nsf.gov)
  • Microtubules play an important role in a number of cellular processes. (wikipedia.org)
  • A large number of cytoplasmic organelles are identifiable in young odontoblasts, whereas, aged odontoblasts lose their columnar shape and contain a small number of Golgi apparatus and a small-sized rough endoblasmic reticulum. (intelligentdental.com)
  • In plants, microtubules retain a role in cell division but also guide cell wall development through their relationship with wall-building enzyme complexes in the plasma membrane[ 9 ]. (biorxiv.org)
  • First, phagophore formation requires cytoplasmic vesicle nucleation, which occurs when the ATG1/ULK1 complex, which is comprised of ULK1, FIP200, ATG13, and ATG101, interacts with the Class III PI3K complex. (hindawi.com)
  • This nucleation process occurs from the minus end, allowing rapid growth from the plus end. (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)
  • 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)
  • They associate with microtubule bundles (MICROTUBULES) and are believed to produce mechanical force via a process linked to GTP hydrolysis. (lookformedical.com)
  • 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)
  • Stalled microtubules might be responsible for some cases of the neurological disorder Charcot-Marie-Tooth (CMT) disease, Tanabe and Takei report. (rupress.org)
  • Microtubules can also morph into other forms such as helical filaments, which are observed in protist organisms like foraminifera. (wikipedia.org)
  • 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)
  • 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)
  • 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)
  • But microtubules from cells that made the faulty version of dynamin 2 were abnormally stable, as measured by how many acetyl groups were attached to them. (rupress.org)
  • Of note, compared to fungal and animal systems, relatively little is known about how plant cells remodel the spindle microtubule array during anaphase. (nsf.gov)
  • Component of cytoplasmic complexes, which also contains PXN, ARHGEF7 and GIT1. (icr.ac.uk)
  • A family of high molecular weight GTP phosphohydrolases that play a direct role in vesicle transport. (lookformedical.com)
  • In addition, this has been associated with the development of phragmosome which is a cytoplasmic diaphragm that forms in preparation for cell division. (microscopemaster.com)
  • Phosphophorin, at a low concentration, acts as a nucleator, but at higher concentration acts as an inhibitor of ionic nucleation. (intelligentdental.com)
  • We showed previously that cytoplasmic release of mtDNA activates the cGAS STING TBK1 pathway resulting in interferon-stimulated gene (ISG) expression that promotes antiviral immunity4. (regenerativemedicine.net)