Many differentiated animal cells, and all higher plant cells, build interphase microtubule arrays of specific architectures without benefit of a central organizer, such as a centrosome, to control the location and geometry of microtubule nucleation. These acentrosomal arrays support essential cell functions such as morphogenesis, but the mechanisms by which the new microtubules are positioned a...

We report the results of studies in which partially purified centrosomes, nuclei, and DNA were injected into frog's eggs, which are naturally arrested in metaphase or interphase. These results have led to an independent assessment of the contributions of the centrosome and the chromatin to the formation of the mitotic spindle and suggest a simple explanation for the transition from interphase t...

The kinesins-8 were originally thought to be microtubule depolymerases, but are now emerging as more versatile catalysts of microtubule dynamics. We show here that S. pombe Klp5-436 and Klp6-440 are non-processive plus-end-directed motors whose in vitro velocities on S. pombe microtubules at 7 and 23 nm s(-1) are too slow to keep pace with the growing tips of dynamic interphase microtubules in ...

Ran is an abundant GTPase of the Ras superfamily that is highly conserved in eukaryotes. In interphase cells, Ran is mainly nuclear and thought to be predominantly GTP-bound, but it is also present in the cytoplasm, probably GDP-bound. This asymmetric distribution plays an important role in directing nucleocytoplasmic transport. Ran has also been implicated in cell cycle control, including the ...

BACKGROUND Microtubule-targeting agents (MTAs) are a mainstay in breast cancer treatment, yet patient responses differ. The underlying mechanisms of these differences are unknown. While MTAs are mitotic inhibitors, recent evidence highlights that non-mitotic effects of these drugs can contribute to their anticancer effects. It is critical to identify the non-mitotic mechanisms that could contri...

BACKGROUND Both symmetric and asymmetric cell divisions are required for the generation of appropriate cell lineages during development. Wild-type Schizosaccharomyces pombe cells divide in a symmetric fashion to produce two similar rod-shaped daughter cells. Formins are proteins with conserved roles in cell polarity, cytokinesis, and the regulation of actin and microtubule cytoskeletons. RESU...

Microtubules regulate diverse cellular processes, including chromosome segregation, nuclear positioning, and cytokinesis. In many organisms, microtubule nucleation requires gamma-tubulin and associated proteins present at specific microtubule organizing centers (MTOCs). In fission yeast, interphase cytoplasmic microtubules originate from poorly characterized interphase MTOCs and spindle pole bo...

Katanin is the only microtubule severing protein identified in plants so far. Previous studies have documented its role in regulating cortical microtubule organization during cell growth and morphogenesis. Although, some cell division defects are reported in KATANIN mutants, it is not clear whether or how katanin activity may affect microtubule dynamics in interphase cells, as well as the progr...

Constructing a mitotic spindle requires the coordinated actions of several kinesin motor proteins. Here, we have visualized the dynamics of five green fluorescent protein (GFP)-tagged mitotic kinesins (class 5, 6, 8, 13, and 14) in live Drosophila Schneider cell line (S2), after first demonstrating that the GFP-tag does not interfere with the mitotic functions of these kinesins using an RNA int...