基因组H2A.Z和DNA甲基化是相互对抗的染色质标记
Daniel Zilberman1, Devin Coleman-Derr, Tracy Ballinger
1University of California, 211 Koshland Hall, Berkeley, California 94720, USA. daniel.zilberman@nature.berkely.edu
Nature
|September 26, 2008
概括
基因甲基化通过排除 histone 变体 H2A.Z 来沉默基因,这通常会促进基因活动. 这项研究揭示了DNA甲基化和H2A.Z在调节染色质结构和基因表达中的关键相互作用.
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.
- 分子生物学分子生物学
- 植物科学 植物科学
背景情况:
- 细胞染色体组织依赖于DNA甲基化和基因组修饰来调节基因.
- 基因甲基化通常会沉默转录,而基因组变异H2A.Z则促进基因活动.
- 在转录调节中,DNA甲基化和H2A.Z之间的相互作用尚未得到充分理解.
研究的目的:
- 为了研究DNA甲基化和H2A.Z沉积在Arabidopsis thaliana之间的关系.
- 阐明DNA甲基化和H2A.Z影响基因转录和染色质结构的机制.
主要方法:
- 分析H2A.Z占用在地区的DNA甲基化在野生类型和突变的Arabidopsis thaliana.
- 研究DNA甲基转移酶MET1和Swr1复合体子单元PIE1中突变对DNA甲基化和H2A.Z沉积的影响.
- 对表观遗传修饰和基因表达的全基因组分析.
主要成果:
- 在Arabidopsis thaliana.中,DNA甲基化区域在H2A.Z方面有数量不足.
- H2A.Z排除发生在活跃转录的基因和转子体内的甲基化位点.
- MET1和PIE1的突变表明DNA甲基化和H2A.Z沉积之间的相互调节,PIE1突变导致全基因组的超甲基化.
结论:
- 基因甲基化有助于基因沉默,通过从染色质中积极排除H2A.Z.
- H2A.Z作为一种保护因素,防止DNA甲基化并保持转录能力.
- 这项研究揭示了一种新的表观遗传调节机制,涉及DNA甲基化和H2A.Z.之间的对抗性相互作用.
相关概念视频
Position-effect Variegation
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
Spreading of Chromatin Modifications
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 is an enzyme that can...
Writers
The writer is an enzyme that can...
Euchromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions take up more dye, appearing darker, while the less-compact areas take up less dye and appear lighter. Based on the compaction level, chromatins are classified into two primary forms – euchromatin and heterochromatin.
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
Euchromatin is the less dense region of the chromatin and stains lighter. Euchromatin contains histone H3 extensively...
DNA Helicases
DNA unwinding helicase enzymes are a type of motor protein. Motor proteins can translocate along filaments or polymers using energy generated from ATP hydrolysis. Helicases are involved in all the important cellular processes where DNA unwinding is required, such as DNA replication, repair, recombination, and transcription. They are present in all living organisms, but vary in their structure, function, and mechanism of action. For example, in prokaryotes, DnaB helicase binds and translocates...
Heterochromatin
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 9th...
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 9th...
Heterochromatin
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 9th...
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 9th...


