基质特异性和蛋白质稳定性推动了植物特异性DNA甲基转移酶的分歧
bioRxiv : the preprint server for biology
|July 29, 2024
概括
植物DNA甲基化酶染色甲基酶3 (CMT3) 和CMT2在进化过程中分离. CMT2是从CMT3进化而来的,但失去了CHG甲基化能力,影响了基因组完整性.
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
- 进化生物学 进化生物学
背景情况:
- 基因组甲基化对于基因组稳定性和转子子沉默至关重要.
- 植物DNA甲基化涉及CHG的染色甲基酶3 (CMT3) 和CHH甲基化的染色甲基酶2 (CMT2).
- 对于CMT酶的基质特异性的进化差异尚不清楚.
研究的目的:
- 研究植物中CMT3和CMT2的进化分歧.
- 了解CMT2失去CHG甲基化活性的分子基础.
- 探索CMT2的N端在蛋白质稳定性和功能中的作用.
主要方法:
- 遗传学分析,以追踪CMT2.2的起源.
- 位点定向突变发生,以评估特定残留物 (如V1200R) 在CMT2活性中的作用.
- 在Arabidopsis突变物中分析DNA甲基化模式.
主要成果:
- CMT2是从CMT3在开花植物中的重复进化而来的.
- 在CMT3中缺少CMT2中的关键氨酸残留物对CHG甲基化至关重要.
- 一个工程突变 (V1200R) 恢复了CMT2中的CHG和CHH甲基化,表明在进化过程中功能丧失.
- CMT2的N端对稳定性至关重要,特别是在热应激下,并且耐受突变.
结论:
- 由于进化变化,CMT2和CMT3在基质特异性上有所不同,主要是失去用于CHG识别的关键残留物.
- CMT2 N端的可塑性有助于其稳定性和适应性.
- 这项研究阐明了染色甲基酶进化的机制,用于植物中特定环境的DNA甲基化.
相关概念视频
RNA Stability
33.4K
Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
33.4K
Mismatch Repair
4.8K
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
4.8K
Export of Mitochondrial and Chloroplast Genes
3.7K
A eukaryotic cell can have up to three different types of genetic systems: nuclear, mitochondrial, and chloroplast. During evolution, organelles have exported many genes to the nucleus; this transfer is still ongoing in some plant species. Approximately 18% of the Arabidopsis thaliana nuclear genome is thought to be derived from the chloroplast’s cyanobacterial ancestor, and around 75% of the yeast genome derived from the mitochondria’s bacterial ancestor. This export has occurred...
3.7K
Conservative Site-specific Recombination and Phase Variation
6.0K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.0K
Evolutionary Relationships through Genome Comparisons
5.7K
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
5.7K
Epigenetic Regulation
3.0K
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...
X-chromosome...
3.0K


