在RNA指导的DNA甲基化位点的聚合酶IV占用需要SHH1
Julie A Law1, Jiamu Du, Christopher J Hale
1Department of Molecular, Cell and Developmental Biology, University of California at Los Angeles, Los Angeles, California 90095, USA.
Nature
|May 3, 2013
概括
萨瓦迪家庭域同类蛋白1 (SHH1) 蛋白质能够在Arabidopsis.中产生siRNA和准DNA甲基化. 一个SHH1的SHH1
科学领域:
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 植物分子生物学 植物分子生物学
- 基因规则 基因规则
背景情况:
- DNA甲基化对于基因沉默和基因组稳定至关重要.
- 在阿拉比多普西斯的RNA导向DNA甲基化 (RdDM) 途径使用小干扰RNA (siRNA) 和植物特异性RNA聚合酶 (Pol-IV,Pol-V).
- 了解Pol-IV的向机制对于控制基因表达至关重要.
研究的目的:
- 研究SAWADEE HOMEODOMAIN HOMOLOG 1 (SHH1) 在RdDM通路中的功能.
- 阐明Pol-IV向的机制及其调节.
- 探索SHH1染色体结合模块的作用.
主要方法:
- 在Arabidopsis中研究了SHH1功能.
- 分析了RdDM目标的siRNA生产和Pol-IV占用率.
- 描述了SHH1 SAWADEE域的染色素结合特性.
- 评估了关键SHH1残留物的体内功能.
主要成果:
- 在RdDM路径上,SHH1作用于上游,使siRNA产生和Pol-IV占用在活跃的RdDM目标上成为可能.
- SHH1 SAWADEE域是一个新的双 lysine 阅读器,识别未甲基化 H3K4 和甲基化 H3K9.
- 在SHH1的氨酸结合口袋中的关键残留物对于维持siRNA水平,DNA甲基化和Pol-IV占用至关重要.
结论:
- 在RdDM通路内的特定位置上准Pol-IV,SHH1起着至关重要的作用.
- SHH1 SAWADEE域的双素结合活性是其功能的核心.
- 了解SHH1的机制为农业和基因治疗相关的表观遗传控制提供了洞察力.
相关概念视频
Restarting Stalled Replication Forks
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart, a...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
Translesion DNA Polymerases
Translesion (TLS) polymerases rescue stalled DNA polymerases at sites of damaged bases by replacing the replicative polymerase and installing a nucleotide across the damaged site. Doing so, TLS allows additional time for the cell to repair the damage before resuming regular DNA replication.
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...

