General regulatory factors (GRFs) as genome partitioners.
Insulators are sequences that uncouple adjacent chromosome domains. Here we have shown that Saccharomyces cerevisiae Rap1p and Abf1p proteins are endowed with a potent insulating capacity. Insulating domains in Rap1p coincide with previously described transcription activation domains, whereas four adjacent subdomains spanning the whole of the Abf1p C terminus (440-731) were found to display autonomous insulating capacity. That both Rap1p and Abf1p silencing domains either contain or largely overlap with an insulating domain suggests that insulation conveys some undefined chromosome organization capacity that also contributes a function in silencing. Together with Reb1p and Tbf1p, previously involved in the activity of Saccharomyces cerevisiae subtelomeric insulators, insulating potential emerges as a supplementary common property of General Regulatory Factors (GRFs). Thus GRFs, which bind to sites scattered throughout the genome within promoters, would not only play a key role in regulating gene expression but also partition the genome in functionally independent domains.
Fourel
Genevieve
G
CNRS/ENSL 5665, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, France. Genevieve.Fourel@ens-lyon.fr
Miyake
Tsuyoshi
T
Defossez
Pierre-Antoine
PA
Li
Rong
R
Gilson
Eric
E
D015825:Chromosomes, Fungal; D004268:DNA-Binding Proteins / Q000502:physiology*; D020868:Gene Silencing; D016681:Genome, Fungal; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins / Q000502:physiology*; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation
C061886:ABF1 protein, S cerevisiae; D004268:DNA-Binding Proteins; C440829:RAP1 protein, S cerevisiae; C065681:REB1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D000089804:Shelterin Complex; D034501:Telomere-Binding Proteins; D014157:Transcription Factors