Noncoding RNA-nucleated heterochromatin spreading is intrinsically labile and requires accessory elements for epigenetic stability.

Autor:	Greenstein RA; Department of Microbiology & Immunology, George Williams Hooper Foundation, University of California San Francisco, San Francisco, United States.; TETRAD graduate program, University of California San Francisco, San Francisco, United States., Jones SK; Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States., Spivey EC; Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States., Rybarski JR; Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States., Finkelstein IJ; Department of Molecular Biosciences, The University of Texas at Austin, Austin, United States.; Center for Systems and Synthetic Biology, The University of Texas at Austin, Austin, United States., Al-Sady B; Department of Microbiology & Immunology, George Williams Hooper Foundation, University of California San Francisco, San Francisco, United States.
Jazyk:	angličtina
Zdroj:	ELife [Elife] 2018 Jul 18; Vol. 7. Date of Electronic Publication: 2018 Jul 18.
DOI:	10.7554/eLife.32948
Abstrakt:	The heterochromatin spreading reaction is a central contributor to the formation of gene-repressive structures, which are re-established with high positional precision, or fidelity, following replication. How the spreading reaction contributes to this fidelity is not clear. To resolve the origins of stable inheritance of repression, we probed the intrinsic character of spreading events in fission yeast using a system that quantitatively describes the spreading reaction in live single cells. We show that spreading triggered by noncoding RNA-nucleated elements is stochastic, multimodal, and fluctuates dynamically across time. This lack of stability correlates with high histone turnover. At the mating type locus, this unstable behavior is restrained by an accessory cis- acting element REIII , which represses histone turnover. Further, REIII safeguards epigenetic memory against environmental perturbations. Our results suggest that the most prevalent type of spreading, driven by noncoding RNA-nucleators, is epigenetically unstable and requires collaboration with accessory elements to achieve high fidelity. Competing Interests: RG, SJ, ES, JR, IF, BA No competing interests declared (© 2018, Greenstein et al.)
Databáze:	MEDLINE
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