Sim4
Open Access
- 28 April 2003
- journal article
- Published by Rockefeller University Press in The Journal of cell biology
- Vol. 161 (2), 295-307
- https://doi.org/10.1083/jcb.200212110
Abstract
Fission yeast centromeres are composed of two domains: the central core and the outer repeats. Although both regions are required for full centromere function, the central core has a distinct chromatin structure and is likely to underlie the kinetochore itself, as it is associated with centromere-specific proteins. Genes placed within either region are transcriptionally silenced, reflecting the formation of a functional kinetochore complex and flanking centromeric heterochromatin. Here, transcriptional silencing was exploited to identify components involved in central core silencing and kinetochore assembly or structure. The resulting sim (silencing in the middle of the centromere) mutants display severe chromosome segregation defects. sim2+ encodes a known kinetochore protein, the centromere-specific histone H3 variant Cnp1CENP-A. sim4+ encodes a novel essential coiled-coil protein, which is specifically associated with the central core region and is required for the unusual chromatin structure of this region. Sim4 coimmunoprecipitates with the central core component Mis6 and, like Mis6, affects Cnp1CENP-A association with the central domain. Functional Mis6 is required for Sim4 localization at the kinetochore. Our analyses illustrate the fundamental link between silencing, chromatin structure, and kinetochore function, and establish defective silencing as a powerful approach for identifying proteins required to build a functional kinetochore.Keywords
This publication has 54 references indexed in Scilit:
- Chromosome-Microtubule Interactions During MitosisAnnual Review of Cell and Developmental Biology, 2002
- The spindle checkpoint: structural insights into dynamic signallingNature Reviews Molecular Cell Biology, 2002
- Distinct Chromosome Segregation Roles for Spindle Checkpoint ProteinsMolecular Biology of the Cell, 2002
- Fission Yeast Mad3p Is Required for Mad2p To Inhibit the Anaphase-Promoting Complex and Localizes to Kinetochores in a Bub1p-, Bub3p-, and Mph1p-Dependent MannerMolecular and Cellular Biology, 2002
- CENP-I Is Essential for Centromere Function in Vertebrate CellsDevelopmental Cell, 2002
- The genome sequence of Schizosaccharomyces pombeNature, 2002
- Ctf3p, the Mis6 budding yeast homolog, interacts with Mcm22p and Mcm16p at the yeast outer kinetochoreGenes & Development, 2002
- M phase–specific kinetochore proteins in fission yeastCurrent Biology, 2001
- The chromatin structure of centromeres from fission yeast: differentiation of the central core that correlates with function.The Journal of cell biology, 1991
- [56] Molecular genetic analysis of fission yeast Schizosaccharomyces pombeMethods in enzymology, 1991