依赖HP1的转录抑制和染色质紧缩的结构机制
Vladyslava Sokolova1, Jacob Miratsky2, Vladimir Svetlov3
1Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY, USA.
Structure (London, England : 1993)
|October 9, 2024
概括
异染色素蛋白1 (HP1) 在两个位点结合了核体,影响了DNA动态,以维持异染色素和静止基因. 这揭示了HP1在DNA损伤反应中的一个新的H3K9me独立作用.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 结构生物学 结构生物学
背景情况:
- 异染色素蛋白1 (HP1) 对于维持异染色素的结构和功能至关重要.
- 精确的HP1-核相互作用机制及其在异色染色体中的作用尚未完全理解.
研究的目的:
- 阐明HP1α-核酶体相互作用的结构基础.
- 了解这些相互作用如何影响核酶体动力学,并有助于维护异色素蛋白和基因沉默.
- 为了研究HP1.1的潜在的H3K9me独立功能.
主要方法:
- 低温电子显微镜 (cryo-EM) 用于确定HP1α与H2A.Z核酶体结合的结构.
- 生物化学测试,以评估HP1α结合对DNA动态的影响.
主要成果:
- 冷-EM结构揭示了核体上两个不同的HP1α结合接口:一个在H3N终端 (K9me3区域) 和一个在H2B (SHL4) 附近的次要位置.
- HP1α结合被证明可以促进核细胞进入/退出部位的DNA解,同时限制SHL4.4附近的DNA可访问性.
- 生物化学数据表明HP1α会影响核细胞体上的DNA动态.
结论:
- 基于已识别的结合接口和DNA动态,提出了一种HP1α介导的异染色质维护和基因沉默模型.
- 该研究强调HP1在DNA损伤反应途径中的H3K9me独立作用.
相关概念视频
Heterochromatin
11.5K
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at...
11.5K
Nucleosome Remodeling
9.0K
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
9.0K
Duplication of Chromatin Structure
5.4K
The process of chromosome duplication during cell division requires genome-wide disruption and re-assembly of chromatin. The chromatin structure must be accurately inherited, reassembled, and maintained in the daughter cells to ensure lineage propagation.
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
The basic unit of the chromatin is the nucleosome, consisting of DNA wrapped around octameric histone proteins and short stretches of linker DNA separating individual nucleosomes. The histone proteins within the nucleosome have their...
5.4K
Spreading of Chromatin Modifications
8.2K
The histone proteins in the nucleosomes are post-translationally modified (PTM) to increase or decrease access to DNA. The commonly observed PTMs are methylation, acetylation, phosphorylation, and ubiquitination of lysine amino acids in the histone H3 tail region. These histone modifications have specific meaning for the cell. Hence, they are called "histone code". The protein complex involved in histone modification is termed as "reader-writer" complex.
Writers
The writer...
Writers
The writer...
8.2K
DNA Packaging
102.2K
Overview
102.2K
Co-activators and Co-repressors
7.3K
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
7.3K


