Regulated recruitment of HP1 to a euchromatic gene induces mitotically heritable, epigenetic gene silencing: a mammalian cell culture model of gene variegation
Open Access
- 17 July 2003
- journal article
- Published by Cold Spring Harbor Laboratory in Genes & Development
- Vol. 17 (15), 1855-1869
- https://doi.org/10.1101/gad.1102803
Abstract
Heterochromatin protein 1 (HP1) is a key component of constitutive heterochromatin inDrosophilaand is required for stable epigenetic gene silencing classically observed as position effect variegation. Less is known of the family of mammalian HP1 proteins, which may be euchromatic, targeted to expressed loci by repressor-corepressor complexes, and retained there by Lys 9-methylated histone H3 (H3-MeK9). To characterize the physical properties of euchromatic loci bound by HP1, we developed a strategy for regulated recruitment of HP1 to an expressed transgene in mammalian cells by using a synthetic, hormone-regulated KRAB repression domain. We show that its obligate corepressor, KAP1, can coordinate all the machinery required for stable gene silencing. In the presence of hormone, the transgene is rapidly silenced, spatially recruited to HP1-rich nuclear regions, assumes a compact chromatin structure, and is physically associated with KAP1, HP1, and the H3 Lys 9-specific methyltransferase, SETDB1, over a highly localized region centered around the promoter. Remarkably, silencing established by a short pulse of hormone is stably maintained for >50 population doublings in the absence of hormone in clonal-cell populations, and the silent transgenes in these clones show promoter hypermethylation. Thus, like variegation inDrosophila, recruitment of mammalian HP1 to a euchromatic promoter can establish a silenced state that is epigenetically heritable.Keywords
This publication has 43 references indexed in Scilit:
- A Kruüppel-Associated Box-Zinc Finger Protein, NT2, Represses Cell-Type-Specific Promoter Activity of the α2(XI) Collagen GeneMolecular and Cellular Biology, 2002
- Retinoblastoma Protein Transcriptional Repression through Histone Deacetylation of a Single NucleosomeMolecular and Cellular Biology, 2002
- Translating the Histone CodeScience, 2001
- Heterochromatin Formation in Mammalian CellsMolecular Cell, 2001
- Targeting histone deacetylase complexes via KRAB-zinc finger proteins: the PHD and bromodomains of KAP-1 form a cooperative unit that recruits a novel isoform of the Mi-2α subunit of NuRDGenes & Development, 2001
- Conserved interaction between distinct Kruppel-associated box domains and the transcriptional intermediary factor 1 betaProceedings of the National Academy of Sciences of the United States of America, 2001
- Molecular Determinants for Targeting Heterochromatin Protein 1-Mediated Gene Silencing: Direct Chromoshadow Domain–KAP-1 Corepressor Interaction Is EssentialMolecular and Cellular Biology, 2000
- HP1γ associates with euchromatin and heterochromatin in mammalian nuclei and chromosomesCytogenetic and Genome Research, 2000
- Reconstitution of the KRAB-KAP-1 repressor complex: a model system for defining the molecular anatomy of RING-B box-coiled-coil domain-mediated protein-protein interactionsJournal of Molecular Biology, 2000
- Reversible Activation of c-Myc in SkinMolecular Cell, 1999