聚蛋白EED在抑制性基因素标记的传播中的作用
Raphael Margueron1, Neil Justin, Katsuhito Ohno
1Howard Hughes Medical Institute and Department of Biochemistry, New York University Medical School, 522 First Avenue, New York, New York 10016, USA.
Nature
|September 22, 2009
概括
在Polycomb Repressive Complex 2 (PRC2) 中的EED蛋白与抑制性基因素标记结合,激活其基因沉默活性. 这种机制有助于维持染色质状态,并在细胞分裂过程中传递表观遗传信息.
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
- 发展生物学 发展生物学
背景情况:
- 聚合组蛋白保持压制性染色体状态.
- 聚合物抑制复合物2 (PRC2) 通过基因素H3氨酸27三甲基化 (H3K27me3) 调解基因沉默.
- EZH2,SUZ12和EED是PRC2.2的关键子单位.
研究的目的:
- 调查EED分部在PRC2活动中的作用.
- 阐明PRC2识别和传播压制性色素标记的机制.
主要方法:
- 生物化学试验研究EED-海斯尾巴相互作用.
- 在实验室中测试PRC2.2.的甲基转移酶活性.
- 在Drosophila中对EED进行基因操纵,以评估发育影响.
主要成果:
- EED的碳氧终端域与基因组尾的三甲基化氨酸残留物结合.
- 这种结合在异质上激活了PRC2.2的甲基转移酶活性.
- 在EED中破坏三甲基-氨酸结合的突变取消了PRC2激活,并导致Drosophila的发育缺陷.
结论:
- EED作为抑制色素标记的传感器,激活PRC2.
- 这种机制对于H3K27me3标记的传播和维持至关重要.
- 这些发现提出了细胞分裂期间表观遗传记忆传递的模型.
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...
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...
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...
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...


