Building mitotic chromosomes

Ohta, Sachio; Wood, Laura; Wills, Jimi; Rappsilber, Juri; Earnshaw, William C.

doi:10.1016/j.ceb.2010.09.009

Cited by 41 publications

(29 citation statements)

References 90 publications

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“…It is now accepted that nonhistone proteins have essential roles in organizing the higher-order structure of mitotic chromosomes. How they accomplish this is still poorly understood (Belmont, 2006; Marko, 2008; Moser and Swedlow, 2011; Ohta et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Mitotic chromosomes are compacted laterally by KIF4 and condensin and axially by topoisomerase IIα

Samejima

Vagnarelli

et al. 2012

Journal of Cell Biology

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Mitotic chromosome formation involves a relatively minor condensation of the chromatin volume coupled with a dramatic reorganization into the characteristic “X” 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 “intrinsic structure” 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 IIα 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.

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Section: Introductionmentioning

confidence: 99%

Mitotic chromosomes are compacted laterally by KIF4 and condensin and axially by topoisomerase IIα

Samejima

Vagnarelli

et al. 2012

Journal of Cell Biology

Self Cite

165

199

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“…Although the substrates and functions of SUMO‐2/3 modification on chromosome arms are unknown, sumoylation is tightly linked to chromatin structure and gene expression in other cell cycle stages . Thus, sumoylation may help regulate the dramatic changes in chromosome structure required for progression through mitosis .…”

Section: Introductionmentioning

confidence: 99%

Identification of SUMO-2/3-modified proteins associated with mitotic chromosomes

et al. 2015

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Sumoylation is essential for progression through mitosis, but the specific protein targets and functions remain poorly understood. In this study, we used chromosome spreads to more precisely define the localization of SUMO-2/3 to the inner-centromere and protein scaffold of mitotic chromosomes. We also developed methods to immunopurify proteins modified by endogenous, untagged SUMO-2/3 from mitotic chromosomes. Using these methods we identified 149 chromosome-associated SUMO-2/3 substrates by nLC-ESI-MS/MS. Approximately one-third of the identified proteins have reported functions in mitosis. Consistent with SUMO-2/3 immunolocalization, we identified known centromere and kinetochore associated proteins, as well as chromosome scaffold associated proteins. Notably, >30 proteins involved in chromatin modification or remodeling were identified. Our results provide insights into the roles of sumoylation as a regulator of chromatin structure and other diverse processes in mitosis. Furthermore, our purification and fractionation methodologies represent an important compliment to existing approaches to identify sumoylated proteins using exogenously expressed and tagged SUMOs.

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“…Spindle formation requires, before M phase, the cell cycle–regulated synthesis of microtubule (MT)-associated proteins (MAPs) at M-phase entry. These include MT motor activities, nonmotor proteins to regulate the dynamic behavior of spindle MTs (Manning and Compton, 2008a,b; Walczak and Heald, 2008), a large variety of chromatin proteins (Ohta et al, 2011), and centrosomal proteins to control MT nucleation and organization at mitotic spindle poles (DeLuca, 2007; Sluder and Khodjakov, 2010). Several proteomic approaches identified spindle proteins on the basis of spindle localization or mitotic MT association (Sauer et al, 2005; Nousiainen et al, 2006).…”

Section: Introductionmentioning

confidence: 99%