Interstitial cells of Hydra attenuata, from which nerve cells and nematocytes (stinging cells) differentiate, were arrested in either metaphase or G2 by different concentrations of the microtubule-depolymerizing agent nocodazole. At a concentration of 1*4 nM-nocodazole, a large number of cells were arrested in metaphase. However, at concentrations of 2 nM-nocodazole and above most of the cells ...

Although the mitogen-activated protein kinase (MAPK) pathway has been extensively investigated, numerous events remain unclear. In the present study, we examined mitogen-activated protein kinase kinase (MEK) expression from interphase to mitosis. Following nocodazole treatment, COS7 cells gradually became round as early as 4 h after treatment. Cyclin B1 expression gradually increased from 4 to ...

Nocodazole is a known destabiliser of microtubule dynamics and arrests cell-cycle at the G2/M phase. In the context of the human embryonic stem cell (hESC) it is important to understand how this arrest influences the pluripotency of cells. Here we report for the first time the changes in the expression of transcription markers Nanog and Oct4 as well as SSEA-3 and SSEA-4 in human embryonic cells...

A polarized cell, to maintain distinct basolateral and apical membrane domains, must tightly regulate vesicular traffic terminating at either membrane domain. In this study we have examined the extent to which microtubules regulate such traffic in polarized cells. Using the polymeric immunoglobulin receptor expressed in polarized MDCK cells, we have examined the effects of nocodazole, a microtu...

The role of microtubules (MTs) in cell locomotion is uncertain: while MTs are not essential for motility of certain cells, MTs are necessary for the directed translocation of large cells such as fibroblasts, endothelial cells and neuronal growth cones. Based on previous studies, we hypothesize that cell locomotion may involve MTs in two possible ways: (1) the rate of cell locomotion is proporti...

BACKGROUND Migrating leukocytes normally have a polarized morphology with an actin-rich lamellipodium at the front and a uropod at the rear. Microtubules (MTs) are required for persistent migration and chemotaxis, but how they affect cell polarity is not known. METHODOLOGY/PRINCIPAL FINDINGS Here we report that T cells treated with nocodazole to disrupt MTs are unable to form a stable uropod ...

We have proposed that stable microtubule (MT) fragments that resist depolymerization may serve as nucleating elements for the local control of MT dynamics in the axon (Heidemann, S. R., M. A. Hamborg, S. J. Thomas, B. Song, S. Lindley, and D. Chu, 1984, J. Cell Biol., 99:1289-1295). Here we report evidence that supports this proposal in studies on the role of MTs in the regrowth of neurites fro...

To investigate the function of calmodulin (CaM) in the mitotic apparatus, the effect of microinjected CaM and chemically modified CaMs on nocodazole-induced depolymerization of spindle microtubules was examined. When metaphase PtK1 cells were microinjected with CaM or a CaM-TRITC conjugate, kinetochore microtubules (kMTs) were protected from the effect of nocodazole. The ability of microinjecte...

Studies on polyploidization of megakaryocytes have been hampered by the lack of synchronized polyploid megakaryocytes. In this study, a relatively synchronized polyploid cell model was successfully established by employing Dami cells treated with nocodazole. In nocodazole-induced cells, cyclin B expression oscillated normally as in diploid cells and polyploid megakaryocytes. By using the nocoda...

Cytogenetic alterations induced by arsenite are associated with its carcinogenic activity. Cytogenetic analysis revealed first that arsenite induced c-anaphases in a time- and dose-dependent manner in human fibroblasts (HFW). With additional incubation of arsenite-arrested mitotic cells in drug-free medium for 0-48 h, approximately 35% exited from mitosis without cell division. This was confirm...