Related Experiment Video
Updated: Jun 10, 2026

Identification of MyoD Interactome Using Tandem Affinity Purification Coupled to Mass Spectrometry
Published on: May 17, 2016
Preferential association of irreversibly silenced E2F-target genes with pericentromeric heterochromatin in
Valentina Guasconi1, Linda-Louise Pritchard, Lauriane Fritsch
1Institut André Lwoff, Centre National de la Recherche Scientifique (CNRS), FRE2944, Université Paris-Sud, Villejuif, France.
Abstract:
The heterochromatin-associated H3K9 tri-methylase Suv39h1 is involved in the permanent silencing of E2F target genes in differentiating but not in quiescent cells. Here, we tested the hypothesis that permanent silencing of E2F target genes is associated with their subnuclear positioning close to the pericentromeric heterochromatin compartment, enriched in Suv39h1. Using fluorescence in situ hybridization, we analyzed the subnuclear localization of three E2F target genes relative to the pericentromeric heterochromatin, in cycling fibroblasts or differentiating myoblasts. We observed that all three E2F-target genes have a tendency to relocate closer to the pericentromeric heterochromatin, only when cells differentiate and undergo an irreversible cell cycle withdrawal. These data suggest that repression of E2F target genes in cycling or in differentiating cells is achieved through distinct mechanisms. In differentiating cells, permanent silencing is driven by a Suv39h1-dependent H3K9 tri-methylation and positioning close to the heterochromatin compartment, whereas repression in cycling cells seems independent from subnuclear positioning and requires distinct H3K9 methylation levels.
Related Concept Videos
Master Transcription Regulators
Heterochromatin
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Euchromatin
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Position-effect Variegation
Inheritance of Chromatin Structures
Satellite Stem Cells and Muscular Dystrophy

