TY - JOUR
T1 - Centrosome biogenesis continues in the absence of microtubules during prolonged S-phase arrest
AU - Collins, Elizabeth S.
AU - Hornick, Jessica E.
AU - Durcan, Thomas M.
AU - Collins, Nicholas S.
AU - Archer, William
AU - Karanjeet, Kul B.
AU - Vaughan, Kevin T.
AU - Hinchcliffe, Edward H
PY - 2010/11
Y1 - 2010/11
N2 - When CHO cells are arrested in S-phase, they undergo repeated rounds of centrosome duplication without cell-cycle progression. While the increase is slow and asynchronous, the number of centrosomes in these cells does rise with time. To investigate mechanisms controlling this duplication, we have arrested CHO cells in S-phase for up to 72 h, and coordinately inhibited new centriole formation by treatment with the microtubule poison colcemid. We find that in such cells, the pre-existing centrosomes remain, and a variable number of foci - containing α/γ-tubulin and centrin 2 - assemble at the nuclear periphery. When the colcemid is washed out, the nuclear-associated foci disappear, and cells assemble new centriole-containing centrosomes, which accumulate the centriole scaffold protein SAS-6, nucleate microtubule asters, and form functional mitotic spindle poles. The number of centrosomes that assemble following colcemid washout increases with duration of S-phase arrest, even though the number of nuclear-associated foci or pre-existing centrosomes does not increase. This suggests that during S-phase, a cryptic generative event occurs repeatedly, even in the absence of new triplet microtubule assembly. When triplet microtubule assembly is restored, these cryptic generative events become realized, and multiple centriole-containing centrosomes assemble.
AB - When CHO cells are arrested in S-phase, they undergo repeated rounds of centrosome duplication without cell-cycle progression. While the increase is slow and asynchronous, the number of centrosomes in these cells does rise with time. To investigate mechanisms controlling this duplication, we have arrested CHO cells in S-phase for up to 72 h, and coordinately inhibited new centriole formation by treatment with the microtubule poison colcemid. We find that in such cells, the pre-existing centrosomes remain, and a variable number of foci - containing α/γ-tubulin and centrin 2 - assemble at the nuclear periphery. When the colcemid is washed out, the nuclear-associated foci disappear, and cells assemble new centriole-containing centrosomes, which accumulate the centriole scaffold protein SAS-6, nucleate microtubule asters, and form functional mitotic spindle poles. The number of centrosomes that assemble following colcemid washout increases with duration of S-phase arrest, even though the number of nuclear-associated foci or pre-existing centrosomes does not increase. This suggests that during S-phase, a cryptic generative event occurs repeatedly, even in the absence of new triplet microtubule assembly. When triplet microtubule assembly is restored, these cryptic generative events become realized, and multiple centriole-containing centrosomes assemble.
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U2 - 10.1002/jcp.22222
DO - 10.1002/jcp.22222
M3 - Article
C2 - 20458743
AN - SCOPUS:77956548292
SN - 0021-9541
VL - 225
SP - 454
EP - 465
JO - Journal of cellular physiology
JF - Journal of cellular physiology
IS - 2
ER -