Nuclear envelope breakdown proceeds by microtubule-induced tearing of the lamina.
The mechanism of nuclear envelope breakdown (NEBD) was investigated in live cells. Early spindle microtubules caused folds and invaginations in the NE up to one hour prior to NEBD, creating mechanical tension in the nuclear lamina. The first gap in the NE appeared before lamin B depolymerization, at the site of maximal tension, by a tearing mechanism. Gap formation relaxed this tension and dramatically accelerated the rate of chromosome condensation. The hole produced in the NE then rapidly expanded over the nuclear surface. NE fragments remaining on chromosomes were removed toward the centrosomes in a microtubule-dependent manner, suggesting a mechanism mediated by a minus-end-directed motor.
Beaudouin
Joël
J
Gene Expression and Cell Biology/Biophysics Programmes, European Molecular Biology Laboratory, D-69117. Heidelberg, Germany
Gerlich
Daniel
D
Daigle
Nathalie
N
Eils
Roland
R
Ellenberg
Jan
J
D000818:Animals; D002460:Cell Line; D002875:Chromosomes / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D016195:G2 Phase / Q000502:physiology; D007668:Kidney / Q000166:cytology; D018386:Kinetochores / Q000378:metabolism; D034921:Lamin Type B; D034882:Lamins; D008565:Membrane Proteins / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology; D009685:Nuclear Envelope / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D051381:Rats; D008941:Spindle Apparatus / Q000378:metabolism
D004268:DNA-Binding Proteins; D034921:Lamin Type B; D034882:Lamins; D008565:Membrane Proteins; D009687:Nuclear Proteins; C082264:Pom121 protein, rat; C093413:lamina-associated polypeptide 2