2. Academic Validation
  3. Ki-67 is a PP1-interacting protein that organises the mitotic chromosome periphery

Ki-67 is a PP1-interacting protein that organises the mitotic chromosome periphery

  • Elife. 2014 May 27;3:e01641. doi: 10.7554/eLife.01641.
Daniel G Booth 1,  Masatoshi Takagi 2,  Luis Sanchez-Pulido 3,  Elizabeth Petfalski 1,  Giulia Vargiu 1,  Kumiko Samejima 1,  Naoko Imamoto 2,  Chris P Ponting 3,  David Tollervey 1,  William C Earnshaw 4,  Paola Vagnarelli 5
Affiliations

Affiliations

  • 1 Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom.
  • 2 Cellular Dynamics Laboratory, Riken Advanced Science Institute, Wako Saitama, Japan.
  • 3 MRC Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
  • 4 Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom bill.earnshaw@ed.ac.uk.
  • 5 Biosciences, Brunel University, London, United Kingdom Paola.Vagnarelli@brunel.ac.uk.
PMID: 24867636 DOI: 10.7554/eLife.01641
Abstract

When the nucleolus disassembles during open mitosis, many nucleolar proteins and RNAs associate with chromosomes, establishing a perichromosomal compartment coating the chromosome periphery. At present nothing is known about the function of this poorly characterised compartment. In this study, we report that the nucleolar protein Ki-67 is required for the assembly of the perichromosomal compartment in human cells. Ki-67 is a cell-cycle regulated protein Phosphatase 1-binding protein that is involved in phospho-regulation of the nucleolar protein B23/nucleophosmin. Following siRNA depletion of Ki-67, NIFK, B23, nucleolin, and four novel chromosome periphery proteins all fail to associate with the periphery of human chromosomes. Correlative LIGHT and electron microscopy (CLEM) images suggest a near-complete loss of the entire perichromosomal compartment. Mitotic chromosome condensation and intrinsic structure appear normal in the absence of the perichromosomal compartment but significant differences in nucleolar reassembly and nuclear organisation are observed in post-mitotic cells.DOI: http://dx.doi.org/10.7554/eLife.01641.001.

Keywords

chromosomes; mitosis; nucleolus; phosphatases.

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