• Our results provide a functional link between two established microcephaly proteins. (ox.ac.uk)
  • The cellular spindle apparatus includes the spindle microtubules, associated proteins, which include kinesin and dynein molecular motors, condensed chromosomes, and any centrosomes or asters that may be present at the spindle poles depending on the cell type. (wikipedia.org)
  • Microtubule-associated proteins (MAPs) associate with microtubules at the midzone and the spindle poles to regulate their dynamics. (wikipedia.org)
  • The growing ends of microtubules are protected against catastrophe by the action of plus-end microtubule tracking proteins (+TIPs) to promote their association with kinetochores at the midzone. (wikipedia.org)
  • CLIP-associated proteins like CLASP1 in humans have also been shown to localize to plus-ends and the outer kinetochore as well as to modulate the dynamics of kinetochore microtubules (Maiato 2003). (wikipedia.org)
  • Opposing the action of these microtubule-stabilizing proteins are a number of microtubule-depolymerizing factors which permit the dynamic remodeling of the mitotic spindle to promote chromosome congression and attainment of bipolarity. (wikipedia.org)
  • The kinesin-13 superfamily of MAPs contains a class of plus-end-directed motor proteins with associated microtubule depolymerization activity including the well-studied mammalian MCAK and Xenopus XKCM1. (wikipedia.org)
  • These proteins harness the energy of ATP hydrolysis to induce destabilizing conformational changes in protofilament structure that cause kinesin release and microtubule depolymerization. (wikipedia.org)
  • It is a progressive, irreversible, and incurable neurodegenerative disorder that disrupts the synaptic communication between millions of neurons, resulting in neuronal death and functional loss due to the abnormal accumulation of two naturally occurring proteins, amyloid β (Aβ) and tau. (frontiersin.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)
  • 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)
  • Thus, in contrast to centrosomes, augmin is crucial for apical progenitor mitosis, and, even in the absence of p53, for progression of brain development. (climat2050.org)
  • In addition, these drugs are known to induce serious side effects due to inhibition of mitosis in other proliferating cells (mainly bone marrow and gut) as well as inhibition of other microtubules-dependent functions, such as neuronal processes [ 18 , 19 ]. (biomedcentral.com)
  • This mitosis-specific recruitment of γ-tubulin does not require microtubules. (silverchair.com)
  • The dynamic exchange of centrosome-associated γ-tubulin occurs throughout the cell cycle, including mitosis, and it does not require microtubules. (silverchair.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)
  • At the pointed ends, known as spindle poles, microtubules are nucleated by the centrosomes in most animal cells. (wikipedia.org)
  • 2016). However, since early mouse development occurs in the absence of centrosomes (Gueth-Hallonet et al. (climat2050.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)
  • Abstract Microtubules that assemble the mitotic spindle are generated by centrosomal nucleation, chromatin-mediated nucleation, and nucleation from the surface of other microtubules mediated by the augmin complex. (climat2050.org)
  • Impairment of centrosomal nucleation in apical progenitors of the developing mouse brain induces p53-dependent apoptosis and causes non-lethal microcephaly. (climat2050.org)
  • Whether disruption of non-centrosomal nucleation has similar effects is usually unclear. (climat2050.org)
  • Centrosomal microtubules were proposed to be at the core of these fate decisions, by controlling the distribution of cell fate determinants through correct positioning of the mitotic spindle (Homem et al. (climat2050.org)
  • γ-Tubulin is a centrosomal component involved in microtubule nucleation. (silverchair.com)
  • Plus-end polymerization may be further moderated by the EB1 protein, which directly binds the growing ends of microtubules and coordinates the binding of other +TIPs. (wikipedia.org)
  • Consistent with this idea, there were significantly fewer free ends of microtubules in the cell bodies of neurons that had been injected with the katanin antibody compared with controls. (silverchair.com)
  • The dynamic lengthening and shortening of spindle microtubules, through a process known as dynamic instability determines to a large extent the shape of the mitotic spindle and promotes the proper alignment of chromosomes at the spindle midzone. (wikipedia.org)
  • Anti-mitotic drugs received considerable attention, especially following the early identification of the anti-cancer properties of microtubules-targeting agents, such as vinca alkaloids [ 15 ] and taxanes [ 16 ]. (biomedcentral.com)
  • 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)
  • ASPM and CITK regulate spindle orientation by affecting the dynamics of astral microtubules. (ox.ac.uk)
  • ASPM and CITK affect the organization of astral microtubules (MT), and low doses of MT-stabilizing drug revert the spindle orientation phenotype produced by their knockdown. (ox.ac.uk)
  • 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)
  • in mammals, CLASP1 and CLASP2 both contribute to proper spindle assembly and microtubule dynamics in anaphase. (wikipedia.org)
  • These data are the first to characterize the dynamics of centrosome-associated γ-tubulin in vertebrate cells in vivo and to demonstrate the microtubule-independent nature of these dynamics. (silverchair.com)
  • Here, we report that AQP5 promotes microtubule assembly and helps maintain the assembled microtubule steady state levels with slower turnover dynamics in cells . (plos.org)
  • These findings indicate that AQP5-mediated regulation of microtubule dynamics modulates airway epithelial barrier properties and epithelial function. (plos.org)
  • In addition, cell expansion does not only rely on cortical microtubule orientation but also plays a regulatory role in microtubule dynamics, as well. (biomedcentral.com)
  • γ-tubulin is a specialized tubulin variant that assembles into a ring complex called γ-TuRC which nucleates polymerization of α/β tubulin heterodimers into microtubules. (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)
  • The pivotal structure of the primary cilia is a microtubule that is generated via tubulin polymerization reaction that occurs in the basal body. (biomedcentral.com)
  • To provide the best actin we can possibly make, our proprietary freeze-drying technique preserves the highly functional actin, to arrive directly at your bench. (hypermol.com)
  • In the absence of nucleators, the polymerization of G-actin is initiated by PolyMix (Cat. (hypermol.com)
  • Multivalent cross-linking of actin filaments and microtubules through the microtubule-associated protein Tau. (hypermol.com)
  • We find that Oral-Facial-Digital syndrome 1 functions as a class II Nucleation promoting factor to promote Arp2/3 complex-mediated actin branching. (bvsalud.org)
  • We show that the absence of CITK leads to abnormal spindle orientation in mammals and insects. (ox.ac.uk)
  • Attachment of microtubules to chromosomes is mediated by kinetochores, which actively monitor spindle formation and prevent premature anaphase onset. (wikipedia.org)
  • In the wide middle portion, known as the spindle midzone, antiparallel microtubules are bundled by kinesins. (wikipedia.org)
  • In this instance, a Ran GTP gradient is the main regulator of spindle microtubule organization and assembly. (wikipedia.org)
  • egg extract and cultured cell models have generated a wealth of information regarding the types of AZD-4320 spindle defects that occur when specific nucleation pathways are compromised, how these defects impinge on cell fate and development remains poorly defined. (climat2050.org)
  • Plant spindle assembly initiates with microtubule nucleation on the nuclear envelope followed by bipolarization into the prophase spindle. (nsf.gov)
  • 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)
  • Gene mutations that cause functional or numerical centrosome aberrations are associated with main microcephaly, a developmental disorder that results in the?reduced thickness of the cerebral cortex. (climat2050.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)
  • Microinjection of an antibody that inactivates katanin results in a dramatic accumulation of microtubules at the centrosome, indicating that katanin is indeed required for microtubule release from the centrosome. (silverchair.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)
  • 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)
  • The centrioles contain nine microtubule triplets and mature into a centrosome that is referred to as a basal body in the context of ciliogenesis [ 22 , 23 ]. (biomedcentral.com)
  • Microtubules also regulate paracellular permeability. (plos.org)
  • Cortical microtubules regulate cell expansion by determining cellulose microfibril orientation in the root apex of Arabidopsis thaliana . (biomedcentral.com)
  • While the regulation of cell wall properties by cortical microtubules is well studied, the data on the influence of cell wall to cortical microtubule organization and stability remain scarce. (biomedcentral.com)
  • The microtubule cytoskeleton is critical for muscle cell differentiation and undergoes reorganisation into an array of paraxial microtubules, which serves as template for contractile sarcomere formation. (elifesciences.org)
  • Studies on cellulose biosynthesis mutants revealed that cortical microtubules depend on Cellulose Synthase A (CESA) function and/or cell expansion. (biomedcentral.com)
  • Furthermore, it has been reported that cortical microtubules in cellulose-deficient mutants are hypersensitive to oryzalin. (biomedcentral.com)
  • In this work, the persistence of cortical microtubules against anti-microtubule treatment was thoroughly studied in the roots of several cesa mutants, namely thanatos , mre1 , any1 , prc1-1 and rsw1 , and the Cellulose Synthase Interacting 1 protein ( csi1) mutant pom2-4 . (biomedcentral.com)
  • Cortical microtubules in all mutants showed statistically significant increased persistence against anti-microtubule drugs, compared to those of the wild-type. (biomedcentral.com)
  • Furthermore, to examine if the enhanced stability of cortical microtubules was due to reduced cellulose biosynthesis or to suppression of cell expansion, treatments of wild-type roots with 2,6-dichlorobenzonitrile (DCB) and Congo red were performed. (biomedcentral.com)
  • After these treatments, cortical microtubules appeared more resistant to oryzalin, than in the control. (biomedcentral.com)
  • Various hypotheses may explain the increased cortical microtubule stability under decreased cell expansion such as the role of cell wall sensors and the presence of less dynamic cortical microtubules. (biomedcentral.com)
  • The regulatory role of cortical microtubules on cellulose microfibrils was initially postulated, and remains widely accepted, by the "alignment hypothesis" [ 4 ]. (biomedcentral.com)
  • However, cortical microtubules reside just under the plasma membrane, while cellulose microfibrils are synthesized by transmembrane CSCs [ 6 ], consisting of CESA subunits. (biomedcentral.com)
  • Even though the "alignment hypothesis" has been proposed decades ago, a mechanism explaining how cortical microtubules, located inside of the plasma membrane, control the orientation of cellulose microfibrils, outside of the protoplast, remained ambiguous. (biomedcentral.com)
  • The direct observation of CESA complexes sliding on the plasma membrane over the cortical microtubules [ 5 ] directly supported the model of Heath [ 16 ]. (biomedcentral.com)
  • Apart from the role of cortical microtubules on cellulose microfibril orientation, several authors supported that CESA activity and cellulose synthesis also exert an effect on cortical microtubule orientation, suggesting thus that cortical microtubule-cellulose microfibril relationship is bi-directional. (biomedcentral.com)
  • The establishment of neural circuits depends on the ability of axonal growth cones to sense their surrounding environment en route to their target. (biologists.com)
  • We have proposed a model whereby these features of the axonal and dendritic microtubule arrays are established within the cell body of the neuron. (silverchair.com)
  • Finally, CITK regulates both astral-MT nucleation and stability. (ox.ac.uk)
  • In contrast, overexpression of AQP5 increased assembly of microtubules, with evidence of increased MT stability, and promoted the formation of long straight microtubules in the apical domain of the epithelial cells. (plos.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)
  • According to these findings, it may be concluded that inhibition of cell expansion, irrespective of the cause, results in increased microtubule stability in A. thaliana root. (biomedcentral.com)
  • Epidemiological evidence from systematic research findings and clinical trials suggests that nutritional and functional dietary isothiocyanates interfere with the molecular cascades of Alzheimer's disease pathogenesis and prevent neurons from functional loss. (frontiersin.org)
  • The issue starts with a summary on Golgi functional organization in neurons (Valenzuela and Perez) and the relation of this organelle with microtubules (Sanders and Kaverina) . (frontiersin.org)
  • Yet, neither the molecular mechanisms underlying the changes in the functional organization of the Golgi apparatus nor their precise relevance to neurodegeneration have yet been completely elucidated. (frontiersin.org)
  • Most notably, oMAP4 is required for paraxial microtubule organisation in muscle cells and prevents dynein- and kinesin-driven microtubule-microtubule sliding. (elifesciences.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)
  • We sought to identify PKA phosphorylation sites in PLIN5 and assess their functional relevance in cultured cells and the livers of mice. (uci.edu)
  • 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)
  • It may be that katanin severs microtubules throughout the cell body to keep them sufficiently short to be efficiently transported into developing processes. (silverchair.com)
  • The microtubules within these processes have a consistent 13-protofilament lattice and are tightly regulated with regard to their polarity orientation. (silverchair.com)
  • 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)
  • Functional amyloids play a beneficial role in a variety of physiologic processes (eg, long-term memory formation, gradual release of stored peptide hormones). (medscape.com)
  • The class II PI3K isoform PI3K-C2β was downregulated in prostate cancer PC3 cells and cervical cancer HeLa cells using selective siRNAs and the effect on cell growth was determined in the absence or presence of the microtubule-stabilizing agent/anti-cancer drug docetaxel. (biomedcentral.com)
  • Cell multi-nucleation was assessed by immunofluorescence. (biomedcentral.com)
  • The functional importance of PP4 in cells is evident by the need of tight regulation of its activity required to maintain cell health. (molcells.org)
  • The outcome of this decision-making process is cell state dependent and, consequently, requires the integration of vast amounts of information that is encoded in the local abundance and functional state of a multitude of biomolecules acting as cell state sensors and transmitters. (biomedcentral.com)
  • Silvestrol-mediated cell death was attenuated in ATG7-null mouse embryonic fibroblasts (MEFs) lacking a functional autophagy protein. (biomedcentral.com)
  • Virus titers in the supernatant of the infected cells for 24 hours in the presence or absence of LY294002 was not collected substantially different, indicating that the lack of expression of RAE Fl step Che. (microrna1.com)
  • Clonogenic assays were performed to determine the ability of PC3 and HeLa cells to form colonies upon PI3K-C2β downregulation in the absence or presence of docetaxel. (biomedcentral.com)
  • 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)
  • 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)
  • It is appropriate to evaluate the genetic status of apparently asymptomatic female relatives (even in the absence of oral, facial, and digital anomalies) to determine if they are at risk for renal disease. (nih.gov)
  • used microscopy to observe the formation of the microtubule filaments in living myoblasts. (elifesciences.org)
  • In Spn mutants, excessive AZs suffered from insufficient evoked release, which may be partly explained by their reduced size, and partly by a genuine functional role of Spn (potentially mediated via Nrx-1 binding). (sdbonline.org)
  • The term motif denotes a repeated figure or design and, in motif biology, the occurrence of a given class of motif in a set of unrelated biomolecules led to the appropriation of the term to refer to a recurrent pattern of nucleotides or amino acids that corresponds to an autonomous functional module. (biomedcentral.com)