Mitotic chromosomes are compacted laterally by KIF4 and condensin and axially by topoisomerase II alpha

作者：Samejima Kumiko; Samejima Itaru; Vagnarelli Paola; Ogawa Hiromi; Vargiu Giulia; Kelly David A; Alves Flavia de Lima; Kerr Alastair; Green Lydia C; Hudson Damien F; Ohta Shinya; Cooke Carol A; Farr Christine J; Rappsilber Juri; Earnshaw William C^*

来源：The Journal of Cell Biology, 2012, 199(5): 755-770.

DOI：10.1083/jcb.201202155

Mitotic chromosome formation involves a relatively minor condensation of the chromatin volume coupled with a dramatic reorganization into the characteristic %26quot;X%26quot; shape. Here we report results of a detailed morphological analysis, which revealed that chromokinesin KIF4 cooperated in a parallel pathway with condensin complexes to promote the lateral compaction of chromatid arms. In this analysis, KIF4 and condensin were mutually dependent for their dynamic localization on the chromatid axes. Depletion of either caused sister chromatids to expand and compromised the %26quot;intrinsic structure%26quot; of the chromosomes (defined in an in vitro assay), with loss of condensin showing stronger effects. Simultaneous depletion of KIF4 and condensin caused complete loss of chromosome morphology. In these experiments, topoisomerase II alpha contributed to shaping mitotic chromosomes by promoting the shortening of the chromatid axes and apparently acting in opposition to the actions of KIF4 and condensins. These three proteins are major determinants in shaping the characteristic mitotic chromosome morphology.

• 出版日期2012-11-26