Disease relevance of Microtubule-Organizing Center

• In contrast, MTOC polarization induced in T cells by antibodies to CD3 or CD28 was significantly inhibited by HTLV-1 infection [1].
• Chlamydia trachomatis uses host cell dynein to traffic to the microtubule-organizing center in a p50 dynamitin-independent process [2].
• Because that attachment is important for the architecture of microtubules (MTs) in epithelia, we analyzed whether chemical anoxia in LLC-PK1 and CACO-2 cells or unilateral ischemia-reperfusion in rat kidney (performed under fluorane anesthesia) had an effect on the binding and distribution of MTOCs [3].

High impact information on Microtubule-Organizing Center

• Nuclear movement regulated by Cdc42, MRCK, myosin, and actin flow establishes MTOC polarization in migrating cells [4].
• Nuclear movement was unaffected by the inhibition of dynein, Par6, or PKCzeta, yet these components were essential for MTOC reorientation, as they maintained the MTOC at the cell centroid [4].
• Antisera recognize a 220 kd protein and stain centrosomes and acentriolar microtubule-organizing centers, where the protein is localized to the pericentriolar material (hence, the name pericentrin) [5].
• Nucleation of microtubules by eukaryotic microtubule organizing centers (MTOCs) is required for a variety of functions, including chromosome segregation during mitosis and meiosis, cytokinesis, fertilization, cellular morphogenesis, cell motility, and intracellular trafficking [6].
• Removing Asp protein function from Drosophila melanogaster embryo extracts, either by mutation or immunodepletion, resulted in loss of their ability to restore microtubule-organizing center activity to salt-stripped centrosome preparations [7].

Biological context of Microtubule-Organizing Center

• At lower doses of DNP-OVA (between 50 and 10 ng/ml), in all couples, LFA-1 and talin were concentrated at the Th/B-APC contact region, but the extent of CD4 clustering, MTOC reorientation, and Th cell proliferation all decreased with decreasing Ag dose [8].
• In agreement with this result, lack of functional Lck, the protein tyrosine kinase responsible for ITAM phosphorylation, abolished both MTOC reorientation and polarized actin polymerization [9].
• In metaphase-arrested eggs only the PCM foci located near the chromosomes acted as MTOCs [10].
• This study demonstrates that the pericentriolar material becomes competent as a microtubule-organizing center (MTOC) at the time of mitosis [11].
• A human autoantiserum (5051) directed against pericentriolar material (PCM) was used to study the distribution of microtubule-organizing centers (MTOCs) in the oocyte and during the first cell cycle of mouse development [10].

Anatomical context of Microtubule-Organizing Center

• Using ZAP-70-deficient T cells expressing zeta-GFP, we show that ZAP-70 signaling drives the TCR-dependent reorientation of the microtubule-organizing center thus leading to relocation of a zeta-GFP(+) intracellular compartment close to the APC [12].
• The main result of our study is to show that in a cell type where the MTOC is dissociated from centrioles and where antero-posterior polarity has disappeared, the association between the Golgi apparatus and the MTOC is maintained [13].
• We found that the proline-rich tyrosine kinase-2 (PYK-2/RAFTK) colocalized with the microtubule-organizing center (MTOC) at the trailing edge of migrating natural killer (NK) cells [14].
• In cells at the wound edge, the immunolabeled Golgi apparatus and microtubule-organizing center were in close proximity to one another and located predominantly forward of the cell nucleus facing the wound [15].
• The intracellular location of the Golgi apparatus and the microtubule-organizing center was determined by double indirect immunofluorescence microscopy, using antibodies specific for the membranes of the Golgi apparatus and antibodies specific for tubulin, respectively [15].

Associations of Microtubule-Organizing Center with chemical compounds

• Switching between plus- and minus end-directed elementary speeds at frequencies up to 1 Hz was observed in the periphery and near the MT organizing center (MTOC) after recovery from nocodazole treatment [16].
• In cells incubated with brefeldin A, most of the BIG2, Exo70, and trans-Golgi protein p230 were widely dispersed from their perinuclear concentrations, but small amounts always remained, apparently at the MTOC [17].
• These results establish an LPA/Cdc42 signaling pathway that regulates MTOC reorientation in a dynein-dependent manner [18].
• We find that in crawling T cells triggered via cross-linking of integrin LFA-1 two PKC isoenzymes, beta(I) and delta, are targeted to the cytoskeleton with specific localization corresponding to the microtubule-organizing center (MTOC) and microtubules, as detected by immunocytochemistry and immunoblotting [19].
• The 350 kDa antigen was part of the thiabendazole-induced cytoplasmic microtubule-organizing centers [20].

Gene context of Microtubule-Organizing Center

• These results suggest that different components of MTOCs act as receptors for gamma-tubulin complexes and that they are essential for the function of MTOCs [21].
• The SOCS-1 SH2 domain is required for the localization of SOCS-1 to the MTOC [22].
• Centrin/Cdc31p is a Ca2+-binding protein related to calmodulin found in the MTOC of diverse organisms [23].
• Microtubule nucleation in vivo requires gamma-tubulin, a highly conserved component of microtubule-organizing centers [24].
• We show that antibodies to intercellular adhesion molecule-1 (ICAM-1; CD54) caused MTOC polarization at a higher frequency in HTLV-1-infected cells [1].

Analytical, diagnostic and therapeutic context of Microtubule-Organizing Center

• Immunofluorescence microscopy reveals that both microtubule organizing center (MTOC) and Golgi apparatus are contained in the same perinuclear area of A549 cells in interphase [25].
• Immunoreactive Exo70 and BIG2 partially or completely overlapped with gamma-tubulin at the MTOC in cells inspected by confocal microscopy [17].

References