Atrx promotes heterochromatin formation at retrotransposons. (21st May 2015)

• Record Type: Journal Article
• Authors: Sadic, Dennis; Schmidt, Katharina; Groh, Sophia; Kondofersky, Ivan; Ellwart, Joachim; Fuchs, Christiane; Theis, Fabian J; Schotta, Gunnar
• Is Part Of: EMBO reports. Volume 16:Number 7(2015:Jul.)
• Page Start: 836
• Page End: 850
• Publication Date: 2015-05-21
• Subjects: Molecular biology -- Periodicals; Molecular Biology -- Periodicals; Molecular biology; Periodicals; 572.8
• DOI: 10.15252/embr.201439937
• Languages: English
• ISSNs: 1469-221X

Abstract

<abstract abstract-type="main" id="embr201439937-abs-0001"> <title>Abstract</title> <p>More than 50% of mammalian genomes consist of retrotransposon sequences. Silencing of retrotransposons by heterochromatin is essential to ensure genomic stability and transcriptional integrity. Here, we identified a short sequence element in intracisternal A particle (IAP) retrotransposons that is sufficient to trigger heterochromatin formation. We used this sequence in a genome‐wide shRNA screen and identified the chromatin remodeler <italic>Atrx</italic> as a novel regulator of IAP silencing. Atrx binds to IAP elements and is necessary for efficient heterochromatin formation. In addition, Atrx facilitates a robust and largely inaccessible heterochromatin structure as <italic>Atrx</italic> knockout cells display increased chromatin accessibility at retrotransposons and non‐repetitive heterochromatic loci. In summary, we demonstrate a direct role of Atrx in the establishment and robust maintenance of heterochromatin.</p> </abstract>