Induction of H3K9me3 and DNA methylation by tethered heterochromatin factors in Neurospora crassa .

Autor: Gessaman JD; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403., Selker EU; Institute of Molecular Biology, University of Oregon, Eugene, OR 97403 selker@uoregon.edu.
Jazyk: angličtina
Zdroj: Proceedings of the National Academy of Sciences of the United States of America [Proc Natl Acad Sci U S A] 2017 Nov 07; Vol. 114 (45), pp. E9598-E9607. Date of Electronic Publication: 2017 Oct 23.
DOI: 10.1073/pnas.1715049114
Abstrakt: Functionally different chromatin domains display distinct chemical marks. Constitutive heterochromatin is commonly associated with trimethylation of lysine 9 on histone H3 (H3K9me3), hypoacetylated histones, and DNA methylation, but the contributions of and interplay among these features are not fully understood. To dissect the establishment of heterochromatin, we investigated the relationships among these features using an in vivo tethering system in Neurospora crassa Artificial recruitment of the H3K9 methyltransferase DIM-5 (defective in methylation-5) induced H3K9me3 and DNA methylation at a normally active, euchromatic locus but did not bypass the requirement of DIM-7, previously implicated in the localization of DIM-5, indicating additional DIM-7 functionality. Tethered heterochromatin protein 1 (HP1) induced H3K9me3, DNA methylation, and gene silencing. The induced heterochromatin required histone deacetylase 1 (HDA-1), with an intact catalytic domain, but HDA-1 was not essential for de novo heterochromatin formation at native heterochromatic regions. Silencing did not require H3K9me3 or DNA methylation. However, DNA methylation contributed to establishment of H3K9me3 induced by tethered HP1. Our analyses also revealed evidence of regulatory mechanisms, dependent on HDA-1 and DIM-5, to control the localization and catalytic activity of the DNA methyltransferase DIM-2. Our study clarifies the interrelationships among canonical aspects of heterochromatin and supports a central role of HDA-1-mediated histone deacetylation in heterochromatin spreading and gene silencing.
Competing Interests: The authors declare no conflict of interest.
(Published under the PNAS license.)
Databáze: MEDLINE