• vitro
  • Using Total-Internal-Reflection-Fluorescence (TIRF) microscopy and a laser tweezers assay to measure in vitro microtubule assembly with nanometer resolution accuracy, we now find that the subunit dissociation rate from a microtubule tip increases at higher free subunit concentrations. (dur.ac.uk)
  • Their work demonstrates that soluble hyperphosphorylated tau, but not aggregated filaments, binds to normal tau and inhibits microtubule assembly in vitro. (alzforum.org)
  • Moving a little bit more to the in vitro side, the work from the Iqbal lab and first author Alejandra del C. Alonso aims to pin down just what form of tau is responsible for interfering with microtubule formation, a process that can trigger apoptosis in neurons. (alzforum.org)
  • Their new work carries this further, by showing that phospho-tau, but not single or paired helical filaments (all isolated from postmortem AD brain), binds N-tau and inhibits microtubule assembly in vitro. (alzforum.org)
  • Typically, microtubules are formed by the parallel association of thirteen protofilaments, although microtubules composed of fewer or more protofilaments have been observed in vitro. (wikipedia.org)
  • Microtubule nucleation occurs spontaneously in vitro, with solutions of purified tubulin giving rise to full-length polymers. (wikipedia.org)
  • Microtubules, in vitro. (wikipedia.org)
  • mitotic
  • Earlier work by Inoué (1952) had shown that when cells are exposed to cold temperatures the mitotic spindle-later shown to be composed of microtubules-disappears. (rupress.org)
  • During cell division, these centrosomes move to opposite ends of the cell and nucleate microtubules to help form the mitotic/meiotic spindle. (wikipedia.org)
  • Hepler then returned to the University of Wisconsin for a postdoctoral fellowship and then became a postdoctoral fellow with Keith Porter at Harvard University from 1966-1967, where he continued his investigation of microtubules, focusing on their role in the mitotic apparatus and the phragmoplast of the endosperm cells of Haemanthus Katharinae. (wikipedia.org)
  • katanin
  • Regulated by several factors, Katanin manifests connective crosstalks in network motifs in regulation of anisotropic severing pattern of microtubule protofilaments in cell type and stage dependent way. (hindawi.com)
  • In this paper, we highlight mechanistic models and regulations of microtubule severing by Katanin in context of structure and various functions of Katanin in different organisms. (hindawi.com)
  • Microtubules are severed by enzymes like Katanin, Spastin, and Fidgetin (Table 1 ). (hindawi.com)
  • Works in last two decades reveal potential role of Katanin in dynamic alteration of microtubule structure and orientation in maintenance of cellular homeostasis. (hindawi.com)
  • Katanin is ubiquitously expressed in plants and lower to higher animals and it systemic or cell specific activity modulates differential formation and organization of microtubule arrays in cell. (hindawi.com)
  • Physiological functioning of Katanin and the resulting microtubule fragmentation is now reported to be important underlying mechanism in cell division, neuron development, cell migration, and locomotory organelle formation. (hindawi.com)
  • In the cortical array of plants, as well as in the axons of neurons, scientists believe that microtubules nucleate from existing microtubules via the action of severing enzymes such as katanin. (wikipedia.org)
  • dynamics
  • Nogales, who is also a professor of biophysics and structural biology at UC Berkeley and investigator with the Howard Hughes Medical Institute, is a leading authority on the structure and dynamics of microtubules. (lbl.gov)
  • The investigators are now exploring how glucose regulates microtubule dynamics. (eurekalert.org)
  • Regulating microtubule dynamics in beta cells, perhaps in combination with other insulin stimulators, offers a new way forward for treating diabetes, the researchers said. (eurekalert.org)
  • A deeper understanding of these dynamics allows us to calculate nanoscale mechanical properties of microtubules such as their force generation and rigidity. (foresight.org)
  • W B Derry, R Luduena: Taxol Differentially Modulates the Dynamics of Microtubules Assembled from Unfractionated and Purified β-Tubulin Isotypes. (foresight.org)
  • Regulation of microtubule dynamics depends on stochastic balance between polymerization and severing process which lead to differential spatiotemporal abundance and distribution of microtubules during cell development, differentiation, and morphogenesis. (hindawi.com)
  • Known for his studies on microtubule dynamics and FtsZ assembly dynamics, Panda is an elected fellow of the Indian Academy of Sciences and the National Academy of Sciences, India. (wikipedia.org)
  • Panda's cell biological research covered the fields of eukaryotic and prokaryotic cell division, dynamics of microtubules and FtsZ, chemotherapeutic treatment protocols, development of FtsZ-targeted antibacterial drugs as well as biomolecular spectroscopy. (wikipedia.org)
  • His work on the dynamics of microtubules is known to have assisted in the development of anti-cancer and anti-fungal drugs and the research on FtsZ assembly has contributed to widening the understanding of their polymerization dynamics. (wikipedia.org)
  • cytoplasmic microtubules
  • Building on the earlier work by Sinnott and Bloch, who had shown that wounding the existing tracheary elements in a Coleus stem induced neighboring parenchyma cells to differentiate into new tracheary elements, Hepler showed that cytoplasmic microtubules were localized specifically in the cortical cytoplasm immediately over the bands of new secondary wall thickenings. (wikipedia.org)
  • subunit
  • In this model, the subunit disassociation rate from a microtubule tip is independent of free subunit concentration. (dur.ac.uk)
  • Because both the association and the dissociation rates increase at higher free subunit concentrations, we find that the kinetics of microtubule assembly are an order-of-magnitude higher than currently estimated in the literature. (dur.ac.uk)
  • actin filaments
  • The common methods in nanobiomechanics are summarized below: Atomic force microscope Optical tweezers Magnetic twisting cytometry bone and its hierarchical constituents such as single collagen fibrils single living cells actin filaments and microtubules synthetic peptide nanotubes In addition to experimental aspect, research has been expanding through computational methods. (wikipedia.org)
  • neurons
  • The recent discovery of quantum vibrations in "microtubules" inside brain neurons corroborates this theory, according to review authors Stuart Hameroff and Sir Roger Penrose. (eurekalert.org)
  • The recent discovery of warm temperature quantum vibrations in microtubules inside brain neurons by the research group led by Anirban Bandyopadhyay, PhD, at the National Institute of Material Sciences in Tsukuba, Japan (and now at MIT), corroborates the pair's theory and suggests that EEG rhythms also derive from deeper level microtubule vibrations. (eurekalert.org)
  • In addition, work from the laboratory of Roderick G. Eckenhoff, MD, at the University of Pennsylvania, suggests that anesthesia, which selectively erases consciousness while sparing non-conscious brain activities, acts via microtubules in brain neurons. (eurekalert.org)
  • Other cells, such as neurons, skeletal muscle cells, and epithelial cells, which do have MTOCs, possess arrays of microtubules not associated with a centrosome. (wikipedia.org)
  • cilia
  • Microtubules are nucleated and organized by microtubule organizing centers (MTOCs), such as the centrosome found in the center of many animal cells or the basal bodies found in cilia and flagella, or the spindle pole bodies found in most fungi. (wikipedia.org)
  • In epithelial cells, MTOCs also anchor and organize the microtubules that make up cilia. (wikipedia.org)
  • The axoneme of primary cilia typically has a ring of nine outer microtubule doublets (called a 9+0 axoneme), and the axoneme of a motile cilium has two central microtubule singlets in addition to the nine outer doublets (called a 9+2 axoneme). (wikipedia.org)
  • MAP2
  • A single study has suggested that MAP2 and tau bind on the inner microtubule surface on the same site in tubulin monomers as the drug Taxol, which is used in treating cancer, but this study has not been confirmed. (wikipedia.org)
  • Like MAP2 and tau, MAP4 is responsible for stabilization of microtubules. (wikipedia.org)
  • MTOCs
  • Some cells however, such as those of higher plants and oocytes, lack distinct MTOCs and microtubules are nucleated via a non-centrosomal pathway. (wikipedia.org)
  • lattice
  • The dynamic instability that makes it possible for microtubules to transition from a rigid polymerized or "assembled" nucleotide state to a flexible depolymerized or "disassembled" nucleotide state is driven by guanosine triphosphate (GTP) hydrolysis in the microtubule lattice. (lbl.gov)
  • Experimental studies have shown that the B-type lattice is the primary arrangement within microtubules. (wikipedia.org)
  • regulate
  • Together with Guoqiang Gu, Ph.D., associate professor of Cell and Developmental Biology, and other Vanderbilt laboratories, the investigators demonstrated using multiple systems and technologies that microtubules negatively regulate insulin secretion in beta cells. (eurekalert.org)
  • The insulin granules 'walk' randomly on the microtubule mesh, and the microtubules regulate the number of granules at the cell periphery to prevent over-secretion," Kaverina said. (eurekalert.org)
  • helical
  • Our new paper updates the evidence, clarifies Orch OR quantum bits, or "qubits," as helical pathways in microtubule lattices, rebuts critics, and reviews 20 testable predictions of Orch OR published in 1998 - of these, six are confirmed and none refuted. (eurekalert.org)
  • Microtubules can also morph into other forms such as helical filaments, which are observed in protist organisms like foraminifera. (wikipedia.org)
  • MTOC
  • The γ-TuRC is typically found as the core functional unit in a microtubule organizing center (MTOC), such as the centrosome in animal cells or the spindle pole bodies in fungi and algae. (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)
  • binds
  • meaning, the heads only binds to the microtubule in one orientation, while ATP binding gives each step its direction through a process known as neck linker zippering. (wikipedia.org)
  • anticancer drugs
  • Beyond their importance to our understanding of basic cell biology, microtubules are a major target for anticancer drugs, such as Taxol, which can prevent the transition from growing to shrinking nucleotide states or vice versa. (lbl.gov)
  • mammalian
  • The new results show that the extra load is lightened in mammalian cells at late anaphase, when microtubules were released both individually and in clusters. (rupress.org)
  • The addition of the DAD to mammalian cells induces actin filament formation, stabilises microtubules, and activates serum-response mediated transcription. (wikipedia.org)
  • growth
  • The authors concluded that "microtubules are intimately involved not only with the maintenance of the axopodia but also with their growth. (rupress.org)
  • We developed a model that describes the different growth and shrinkage behavior of each isotype in terms of a recursive map representation based on a modified random walk with four independent probabilistic variables describing the possible states of a microtubule. (foresight.org)
  • Using further probabilistic methods, we simulated the growth and shrinkage behavior of isotypically pure microtubules and determined their average growth and shrinkage rate constants and their probability distributions. (foresight.org)
  • This variation in growth and shrinkage rates subsequently leads to a variation in the forces generated by isotypically purified microtubules that were calculated from a force-velocity relationship. (foresight.org)
  • It has also been suggested that microtubule rigidity is directly related to the rate of growth, and that slower growing microtubules are stiffer. (foresight.org)
  • Here again, the β-tubulin isotype composition can be varied in order to produce a microtubule with a specific growth rate, in order to produce a microtubule of desired rigidity. (foresight.org)
  • Stoppin-Mellet V, Fache V, Portran D, Martiel J-L, Vantard M (2013) MAP65 Coordinate Microtubule Growth during Bundle Formation. (plos.org)
  • The γ-TuRC also acts as a cap of the (−) end while the microtubule continues growth from its (+) end. (wikipedia.org)
  • There is also, a class of the +TIPs which substantiates a TOG domain, arranged properly these domains allow mediation of binding to tubulin and are important for microtubule growth correlated activity. (wikipedia.org)
  • dynamic
  • Because the freed microtubules are not protected at their minus ends, they are more dynamic and turn over more rapidly than attached microtubules. (rupress.org)
  • A better understanding of how microtubule dynamic instability is regulated could open new opportunities for improving the potency and selectivity of existing anti-cancer drugs, as well as facilitate the development of novel agents," Nogales says. (lbl.gov)
  • The findings suggest that in response to the increased demand for insulin in diabetes, microtubules become more dense and less dynamic as a feedback mechanism, ultimately shutting down beta cell function, Gu said. (eurekalert.org)
  • This enables us to extrapolate these results to a model that can predict the dynamic instability of microtubules with an arbitrary isotype composition. (foresight.org)
  • These dyneins have their light chains (static portion) attached to the cell membrane, and their globular parts (dynamic portions) attached to the microtubules. (wikipedia.org)