JCB logo
Accuri Cytometers
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 2257K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Saurin, A. J.
Right arrow Articles by Freemont, P. S.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Saurin, A. J.
Right arrow Articles by Freemont, P. S.
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/1998//887 $5.00
The Journal of Cell Biology, Volume 142, Number 4, , 1998 887-898

Articles

The Human Polycomb Group Complex Associates with Pericentromeric Heterochromatin to Form a Novel Nuclear Domain



Andrew J. Saurin*, Carol Shiels{ddagger}, Jill Williamson{ddagger}, David P.E. Satijn§, Arie P. Otte§, Denise Sheer{ddagger}, and Paul S. Freemont*

* Molecular Structure and Function Laboratory and {ddagger} Human Cytogenetics Laboratory, Imperial Cancer Research Fund, London WC2A 3PX, United Kingdom; and § E.C. Slater Institute, University of Amsterdam, 1018 TV Amsterdam, The Netherlands

The Polycomb group (PcG) complex is a chromatin-associated multiprotein complex, involved in the stable repression of homeotic gene activity in Drosophila. Recently, a mammalian PcG complex has been identified with several PcG proteins implicated in the regulation of Hox gene expression. Although the mammalian PcG complex appears analogous to the complex in Drosophila, the molecular mechanisms and functions for the mammalian PcG complex remain unknown. Here we describe a detailed characterization of the human PcG complex in terms of cellular localization and chromosomal association. By using antibodies that specifically recognize three human PcG proteins— RING1, BMI1, and hPc2—we demonstrate in a number of human cell lines that the PcG complex forms a unique discrete nuclear structure that we term PcG bodies. PcG bodies are prominent novel nuclear structures with the larger PcG foci generally localized near the centromeres, as visualized with a kinetochore antibody marker. In both normal fetal and adult fibroblasts, PcG bodies are not randomly dispersed, but appear clustered into defined areas within the nucleus. We show in three different human cell lines that the PcG complex can tightly associate with large pericentromeric heterochromatin regions (1q12) on chromosome 1, and with related pericentromeric sequences on different chromosomes, providing evidence for a mammalian PcG–heterochromatin association. Furthermore, these heterochromatin-bound PcG complexes remain stably associated throughout mitosis, thereby allowing the potential inheritance of the PcG complex through successive cell divisions. We discuss these results in terms of the known function of the PcG complex as a transcriptional repression complex.

Key Words: Polycomb-group • RING finger protein • centromere • heterochromatin • repression

Abbreviations used in this paper: FISH, fluorescence in situ hybridization; NBS, newborn serum; PREs, PcG response elements; PTB, polypyrimidine tract-binding protein.

We are particularly indebted to those colleagues cited in Materials and Methods who kindly provided antibodies against other known nuclear protein complexes. We also thank Nicola O'Reilly for peptide synthesis and Graham Warren and David Ish-Horowicz for their useful comments on the manuscript.

Address all correspondence to Paul S. Freemont, Molecular Structure and Function Laboratory, Imperial Cancer Research Fund, P.O. Box 123, 44 Lincoln's Inn Fields, London, WC2A3PX, United Kingdom. Tel.: +44-171-269-3291. Fax: +44-171-269-3671 (or 3258). E-mail: freemont{at}icrf.icnet.uk


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents