|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | |||||
First published online 23 October 2007
doi: 10.1242/jcs.013730
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Research Article |
leads to shortening of the metaphase interkinetochore distance and abnormal persistence of PICH-coated anaphase threads

1 Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, UK
2 Haemostasis and Thrombosis Group, Medical Research Council Clinical Sciences Centre, Faculty of Medicine, Imperial College, Hammersmith Hospital Campus, London W12 0NN, UK
3 Department of Haematology, Faculty of Medicine, Imperial College, London W12 0NN, UK
¶ Author for correspondence (e-mail: c_farr{at}mole.bio.cam.ac.uk)
Accepted 27 August 2007
Topoisomerase II (topo II) is a major component of mitotic chromosomes, and its unique decatenating activity has been implicated in many aspects of chromosome dynamics, of which chromosome segregation is the most seriously affected by loss of topo II activity in living cells. There is considerable evidence that topo II plays a role at the centromere including: the centromere-specific accumulation of topo II protein; cytogenetic/molecular mapping of the catalytic activity of topo II to active centromeres; the influence of sumoylated topo II on sister centromere cohesion; and its involvement in the activation of a Mad2-dependent spindle checkpoint. By using a human cell line with a conditional-lethal mutation in the gene encoding DNA topoisomerase II
, we find that depletion of topo II
, while leading to a disorganised metaphase plate, does not have any overt effect on general assembly of kinetochores. Fluorescence in situ hybridisation suggested that centromeres segregate normally, most segregation errors being chromatin bridges involving longer chromosome arms. Strikingly, a linear human X centromere-based minichromosome also displayed a significantly increased rate of missegregation. This sensitivity to depletion of topo II
might be linked to structural alterations within the centromere domain, as indicated by a significant shortening of the distance across metaphase sister centromeres and the abnormal persistence of PICH-coated connections between segregating chromatids.
Key words: Topoisomerase, PICH, Chromosome, Centromere, Condensation, Segregation
![]()
CiteULike
Complore
Connotea
Del.icio.us
Digg
Reddit
Technorati
Twitter What's this?
This article has been cited by other articles:
![]() |
M. Johnson, H. H. Phua, S. C. Bennett, J. M. Spence, and C. J. Farr Studying vertebrate topoisomerase 2 function using a conditional knockdown system in DT40 cells Nucleic Acids Res., August 1, 2009; 37(14): e98 - e98. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. A. Ribeiro, J. C. Gatlin, Y. Dong, A. Joglekar, L. Cameron, D. F. Hudson, C. J. Farr, B. F. McEwen, E. D. Salmon, W. C. Earnshaw, et al. Condensin Regulates the Stiffness of Vertebrate Centromeres Mol. Biol. Cell, May 1, 2009; 20(9): 2371 - 2380. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. H. Warsi, M. S. Navarro, and J. Bachant DNA Topoisomerase II Is a Determinant of the Tensile Properties of Yeast Centromeric Chromatin and the Tension Checkpoint Mol. Biol. Cell, October 1, 2008; 19(10): 4421 - 4433. [Abstract] [Full Text] [PDF] |
||||