E(y)2/Sus1 is required for blocking PRE silencing by the Wari insulator in Drosophila melanogaster.
Chromatin insulators affect interactions between promoters and enhancers/silencers and function as barriers to the spread of repressive chromatin. Recently, we have found an insulator, named Wari, located on the 3' side of the white gene. Here, we show that the previously identified 368-bp core of this insulator is sufficient for blocking Polycomb response element-mediated silencing. Although Wari does not contain binding sites for known insulator proteins, the E(y)2 and CP190 proteins bind to Wari as well as to the Su(Hw)-containing insulators in vivo. It may well be that these proteins are recruited to the insulator by as yet unidentified DNA-binding protein. Partial inactivation of E(y)2 in a weak e(y)2 ( u1 ) mutation impairs only the anti-silencing but not the enhancer-blocking activity of the Wari insulator. Thus, the E(y)2 protein in different Drosophila insulators serves to protect gene expression from silencing.
Erokhin
Maksim
M
Department of the Control of Genetic Processes, Institute of Gene Biology, Russian Academy of Sciences, 34/5 Vavilov St, Moscow, 119334, Russia.
Parshikov
Alexander
A
Georgiev
Pavel
P
Chetverina
Darya
D
D000818:Animals; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D020868:Gene Silencing; D038101:Insulator Elements; D063150:Polycomb Repressive Complex 1; D011485:Protein Binding; D020218:Response Elements; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029721:Drosophila Proteins; C066770:Pc protein, Drosophila; D014157:Transcription Factors; C423782:e(y)2 protein, Drosophila; D063150:Polycomb Repressive Complex 1