TY - JOUR
T1 - Kinesin-5-dependent poleward flux and spindle length control in Drosophila embryo mitosis
AU - Brust-Mascher, Ingrid
AU - Sommi, Patrizia
AU - Cheerambathur, Dhanya K.
AU - Scholey, Jonathan M.
PY - 2009/3/15
Y1 - 2009/3/15
N2 - We used antibody microinjection and genetic manipulations to dissect the various roles of the homotetrameric kinesin-5,KLP61F, in astral, centrosome-controlled Drosophila embryo spindles and to test the hypothesis that it slides apart interpolar (ip) microtubules (MT), thereby controlling poleward flux and spindle length. In wild-type and Ncd null-mutant embryos, anti-KLP61F dissociated the motor from spindles, producing a spatial gradient in the KLP61F content of different spindles, which was visible in KLP61F-GFP transgenic embryos. The resulting mitotic defects, supported by gene dosage experiments and time-lapse microscopy of living klp61f mutants, reveal that, after NEB, KLP61F drives persistent MT bundling and the outward sliding of antiparallel MTs, thereby contributing to several processes that all appear insensitive to cortical disruption. KLP61F activity contributes to the poleward flux of both ipMTs and kinetochore MTs and to the length of the metaphase spindle. KLP61F activity maintains the prometaphase spindle by antagonizing Ncd and another unknown force-generator and drives anaphase B, although the rate of spindle elongation is relatively insensitive to the motoŕs concentration. Finally, KLP61F activity contributes to normal chromosome congression, kinet-ochore spacing, and anaphase A rates. Thus, a KLP61F-driven sliding filament mechanism contributes to multiple aspects of mitosis in this system.
AB - We used antibody microinjection and genetic manipulations to dissect the various roles of the homotetrameric kinesin-5,KLP61F, in astral, centrosome-controlled Drosophila embryo spindles and to test the hypothesis that it slides apart interpolar (ip) microtubules (MT), thereby controlling poleward flux and spindle length. In wild-type and Ncd null-mutant embryos, anti-KLP61F dissociated the motor from spindles, producing a spatial gradient in the KLP61F content of different spindles, which was visible in KLP61F-GFP transgenic embryos. The resulting mitotic defects, supported by gene dosage experiments and time-lapse microscopy of living klp61f mutants, reveal that, after NEB, KLP61F drives persistent MT bundling and the outward sliding of antiparallel MTs, thereby contributing to several processes that all appear insensitive to cortical disruption. KLP61F activity contributes to the poleward flux of both ipMTs and kinetochore MTs and to the length of the metaphase spindle. KLP61F activity maintains the prometaphase spindle by antagonizing Ncd and another unknown force-generator and drives anaphase B, although the rate of spindle elongation is relatively insensitive to the motoŕs concentration. Finally, KLP61F activity contributes to normal chromosome congression, kinet-ochore spacing, and anaphase A rates. Thus, a KLP61F-driven sliding filament mechanism contributes to multiple aspects of mitosis in this system.
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U2 - 10.1091/mbc.E08-10-1033
DO - 10.1091/mbc.E08-10-1033
M3 - Article
C2 - 19158379
AN - SCOPUS:65249190848
VL - 20
SP - 1749
EP - 1762
JO - Molecular Biology of the Cell
JF - Molecular Biology of the Cell
SN - 1059-1524
IS - 6
ER -