基因边界的负超线圈调节了基因拓
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在PubMed上查看摘要
概括
此摘要是机器生成的。在复制和转录过程中,DNA拓对于染色体的完整性至关重要. 这项研究揭示了DNA拓酶Top1,Top2和Hmo1蛋白如何维持基因结构并防止冲突.
科学领域
- 分子生物学
- 遗传学
- 生物化学
背景情况
- DNA复制和转录产生拓压力,挑战染色体的完整性.
- 在细胞过程中管理DNA拓酶 (Top1,Top2) 和HMGB蛋白 (Hmo1) 是必不可少的.
研究的目的
- 在G1和S阶段阐明Saccharomyces cerevisiae基因的拓结构.
- 了解Top1,Top2和Hmo1在维护DNA拓和预防复制和转录过程中的冲突中的作用.
主要方法
- 在不同细胞周期阶段对基因区域内的DNA拓分析.
- 研究Top1,Top2和Hmo1在调节DNA超级卷和预防转录相关冲突中的作用.
主要成果
- 在基因边界和编码区域内识别过多的DNA,独立于Pol II或S阶段.
- 在基因边界,Top2和Hmo1保持负超线圈,而Top1则在编码区域内起作用.
- 在S阶段,Hmo1保护伤下DNA,Top2限制聚合酶和Top1,防止转录泄漏和异常RNA-DNA杂交.
结论
- 这项研究揭示了基因组稳定性至关重要的特定拓结构.
- Hmo1和Top2调节基因架构,可能将基因边界锁定在十字形形状中,并保留拓记忆.
- 这种拓调节对于防止复制,转录和保持基因组完整性之间的冲突至关重要.
相关概念视频
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
Topoisomerases are enzymes that relax overwound DNA molecules during various cell processes, including DNA replication and transcription. These enzymes regulate positive and negative DNA supercoiling without changing the nucleotide sequence. DNA overwinding in a clockwise direction results in positively supercoiled DNA, whereas underwinding in a counterclockwise direction produces negatively supercoiled DNA.
Types and Mechanism of action
Topoisomerases are divided into two main types. ...
Epigenetic changes alter the physical structure of the DNA without changing the genetic sequence and often regulate whether genes are turned on or off. This regulation ensures that each cell produces only proteins necessary for its function. For example, proteins that promote bone growth are not produced in muscle cells. Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
X-chromosome...
Epigenetic mechanisms play an essential role in healthy development. Conversely, precisely regulated epigenetic mechanisms are disrupted in diseases like cancer.
In most mammals, females have two X chromosomes (XX) while males have an X and a Y chromosome (XY). The X chromosome contains significantly more genes than the Y chromosome. Therefore, to prevent an excess of X chromosome-linked gene expression in females, one of the two X chromosomes is randomly silenced during early development....
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...