H3K27脱甲基酶,在最后一个长时间
1Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305, USA.
Cell
|October 10, 2007
概括
聚合物抑制复合体2 (PRC2) 蛋白质在素27 (H3K27me) 处甲基化素H3以使基因沉默. UTX和JMJD3脱甲基酶去除了这种标记,激活了发育和免疫的基因.
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
- 发育生物学 发展生物学
背景情况:
- 基因组甲基化,特别是H3K27me,是一种由Polycomb Repressive Complex 2 (PRC2) 调节的关键表观遗传标记.
- H3K27me通常与基因沉默有关,并在发育过程中发挥关键作用.
- 清除H3K27me和随后的基因激活的精确机制尚未完全阐明.
研究的目的:
- 为了识别和描述负责H3K27me.me去甲基化的酶.
- 了解H3K27me的去除如何影响发育和炎症情境中的基因表达.
主要方法:
- 生物化学试验测试脱甲基酶对H3K27me的活性.
- 在模型生物中进行遗传研究,以评估已识别的脱甲基酶的功能.
- 在去甲基酶活动后对基因表达变化的分析.
主要成果:
- 确定JmjC域蛋白UTX和JMJD3是特定的H3K27脱甲基酶.
- UTX和JMJD3催化了H3K27me标记的去除.
- 通过UTX和JMJD3的脱甲基化导致关键的基因的激活动物的身体模式和炎症反应.
结论:
- UTX和JMJD3是关键的H3K27特异性脱甲基酶.
- 这些脱甲基酶对H3K27me的动态调节对于激活关键的发育和免疫基因至关重要.
- 这些发现揭示了在发育和免疫过程中对基因表达的表观遗传控制的新机制.
相关概念视频
02:25Spreading 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...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:32Histone Modification
The histone proteins have a flexible N-terminal tail extending out from the nucleosome. These histone tails are often subjected to post-translational modifications such as acetylation, methylation, phosphorylation, and ubiquitination. Particular combinations of these modifications form “histone codes” that influence the chromatin folding and tissue-specific gene expression.
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
Acetylation
The enzyme histone acetyltransferase adds acetyl group to the histones. Another enzyme, histone deacetylase,...
02:30Histone Variants at the Centromere
Histone variants are the histone proteins with structural and sequence variations. These variants may be regarded as “mutant” forms that replace their canonical histone counterparts in the nucleosomes. Specific post-translational modifications on the histone variants enable further chromatin complexity and regulate tissue-specific gene expression. The most common histone variants are from histone H2A, H2B, and linker histone H1 families. However, several variants of histone H3 variants are also...
02:32Position-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.
02:38Heterochromatin
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...