학술논문
Live-cell analysis of mitotic spindle formation in taxol-treated cells.
Document Type
Academic Journal
Author
Hornick JE; Department of Biological Sciences and Notre Dame Integrated Imaging Facility, University of Notre Dame, Notre Dame, Indiana 46556, USA. Hinchcliffe.3@nd.edu; Bader JR; Tribble EK; Trimble K; Breunig JS; Halpin ES; Vaughan KT; Hinchcliffe EH
Source
Publisher: Wiley-Liss Country of Publication: United States NLM ID: 8605339 Publication Model: Print Cited Medium: Internet ISSN: 1097-0169 (Electronic) Linking ISSN: 08861544 NLM ISO Abbreviation: Cell Motil Cytoskeleton Subsets: MEDLINE
Subject
Language
English
Abstract
Taxol functions to suppress the dynamic behavior of individual microtubules, and induces multipolar mitotic spindles. However, little is known about the mechanisms by which taxol disrupts normal bipolar spindle assembly in vivo. Using live imaging of GFP-alpha tubulin expressing cells, we examined spindle assembly after taxol treatment. We find that as taxol-treated cells enter mitosis, there is a dramatic re-distribution of the microtubule network from the centrosomes to the cell cortex. As they align there, the cortical microtubules recruit NuMA to their embedded ends, followed by the kinesin motor HSET. These cortical microtubules then bud off to form cytasters, which fuse into multipolar spindles. Cytoplasmic dynein and dynactin do not re-localize to cortical microtubules, and disruption of dynein/dynactin interactions by over-expression of p50 "dynamitin" does not prevent cytaster formation. Taxol added well before spindle poles begin to form induces multipolarity, but taxol added after nascent spindle poles are visible-but before NEB is complete-results in bipolar spindles. Our results suggest that taxol prevents rapid transport of key components, such as NuMA, to the nascent spindle poles. The net result is loss of mitotic spindle pole cohesion, microtubule re-distribution, and cytaster formation.
((c) 2008 Wiley-Liss, Inc.)
((c) 2008 Wiley-Liss, Inc.)