Chromosome-induced microtubule assembly mediated by TPX2 is required for spindle formation in HeLa cells.
In Xenopus laevis egg extracts, TPX2 is required for the Ran-GTP-dependent assembly of microtubules around chromosomes. Here we show that interfering with the function of the human homologue of TPX2 in HeLa cells causes defects in microtubule organization during mitosis. Suppressing the expression of human TPX2 by RNA interference leads to the formation of two microtubule asters that do not interact and do not form a spindle. Our results suggest that in vivo, even in the presence of duplicated centrosomes, spindle formation requires the function of TPX2 to generate a stable bipolar spindle with overlapping antiparallel microtubule arrays. This indicates that chromosome-induced microtubule production is a general requirement for the formation of functional spindles in animal cells.
Gruss
Oliver J
OJ
EMBL, Meyerhofstrasse 1, 69 117 Heidelberg, Germany.
Wittmann
Malte
M
Yokoyama
Hideki
H
Pepperkok
Rainer
R
Kufer
Thomas
T
Silljé
Herman
H
Karsenti
Eric
E
Mattaj
Iain W
IW
Vernos
Isabelle
I
D000818:Animals; D015153:Blotting, Western; D002460:Cell Line; D002875:Chromosomes / Q000648:ultrastructure*; D018076:DNA, Complementary / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006367:HeLa Cells; D006801:Humans; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008870:Microtubules / Q000648:ultrastructure; D008938:Mitosis; D015739:Nocodazole / Q000494:pharmacology; D009865:Oocytes / Q000378:metabolism; D010641:Phenotype; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016196:S Phase; D008941:Spindle Apparatus; D013997:Time Factors; D014982:Xenopus laevis / Q000378:metabolism; D020931:ran GTP-Binding Protein / Q000378:metabolism
D018076:DNA, Complementary; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D020931:ran GTP-Binding Protein; D015739:Nocodazole