酵母端粒异染色质的分子模型。

Molecular model for telomeric heterochromatin in yeast.

作者信息

Grunstein M

机构信息

Department of Biological Chemistry, UCLA School of Medicine, Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA.

出版信息

Curr Opin Cell Biol. 1997 Jun;9(3):383-7. doi: 10.1016/s0955-0674(97)80011-7.

DOI:10.1016/s0955-0674(97)80011-7

PMID:9159071

Abstract

A molecular model for the formation of yeast core telomeric heterochromatin has been proposed recently. The RAP1 protein provides the specificity for the localization of heterochromatin through its recognition of telomeric DNA sequences. Its complexing with silencing information regulators (SIR2, SIR3 and SIR4) and histones H3 and H4 generates a folded-back DNA structure. This not only represses adjacent genes through SIR-protein-histone interactions, but also enables condensation and protection of the telomeric end. The SIR2 and SIR4 levels at the core differ from those in the extended telomeric heterochromatin produced when the limiting protein, SIR3, is overexpressed.

摘要

最近有人提出了一种酵母核心端粒异染色质形成的分子模型。RAP1蛋白通过识别端粒DNA序列为异染色质的定位提供特异性。它与沉默信息调节因子（SIR2、SIR3和SIR4）以及组蛋白H3和H4结合，产生一种折返的DNA结构。这不仅通过SIR蛋白-组蛋白相互作用抑制相邻基因，还能使端粒末端浓缩并得到保护。核心区域的SIR2和SIR4水平与当限制蛋白SIR3过表达时产生的延伸端粒异染色质中的水平不同。