Modulations of SIR-nucleosome interactions of reconstructed yeast silent pre-heterochromatin by O-acetyl-ADP-ribose and magnesium.

Yeast silent heterochromatin provides an excellent model with which to study epigenetic inheritance. Previously we developed an in vitro assembly system to demonstrate the formation of filament structures with requirements that mirror yeast epigenetic gene silencing in vivo. However, the properties of these filaments were not investigated in detail. Here we show that the assembly system requires Sir2, Sir3, Sir4, nucleosomes, and O-acetyl-ADP-ribose. We also demonstrate that all Sir proteins and nucleosomes are components of these filaments to prove that they are SIR-nucleosome filaments. Furthermore, we show that the individual localization patterns of Sir proteins on the SIR-nucleosome filament reflect those patterns on telomeres in vivo. In addition, we reveal that magnesium exists in the SIR-nucleosome filament, with a role similar to that for chromatin condensation. These results suggest that a small number of proteins and molecules are sufficient to mediate the formation of a minimal yeast silent pre-heterochromatin in vitro. © 2017 Tung et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

Citation

Shu-Yun Tung, Sue-Hong Wang, Sue-Ping Lee, Shu-Ping Tsai, Hsiao-Hsuian Shen, Feng-Jung Chen, Yu-Yi Wu, Sheng-Pin Hsiao, Gunn-Guang Liou. Modulations of SIR-nucleosome interactions of reconstructed yeast silent pre-heterochromatin by O-acetyl-ADP-ribose and magnesium. Molecular biology of the cell. 2017 Feb 01;28(3):381-386

Mesh Tags

Substances

PMID: 27932495

search → result