不同染色质和RNAi是建立CENP-A染色质在中间体的必要条件
Hernan Diego Folco1, Alison L Pidoux, Takeshi Urano
1Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, School of Biological Sciences, University of Edinburgh, 6.34 Swann Building, Edinburgh EH9 3JR, Scotland, UK.
Science (New York, N.Y.)
|January 5, 2008
概括
导向RNA干扰 (RNAi) 的异位染色体对于在裂变酵母中位的CENP-A染色体和动态基因组合至关重要. 这种 heterochromatin 引导初始组装,之后 CENP-A 染色体被表观遗传维护.
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
- 染色体生物学 染色体生物学
背景情况:
- 异染色素,标记为基因素H3氨酸9甲基化 (H3K9me),招募异染色素蛋白1 (HP1) 并在CENP-A染色素附近发现,对于动态细胞组装至关重要.
- 中心色素,特别是CENP-A,对于细胞分裂期间适当的染色体分离至关重要.
研究的目的:
- 调查RNA干扰 (RNAi) 导向的异染色素在裂变酵母中心体中CENP-A染色素和动态基因组合中的作用.
- 确定建立和维护中心性异色素的关键因素及其与CENP-A.A.的关系.
主要方法:
- 利用裂变酵母作为一个模型生物.
- 研究了关键蛋白质的功能,包括H3K9甲基转移酶Clr4,核糖核酶Dicer,RNA诱导的转录基因沉默 (RITS) 组件Chp1和Swi6 (HP1) 的功能.
- 检查了对CENP-A ((Cnp1) 和对原始中心模板上的kinetochore组装的这些因素的要求.
主要成果:
- 证明了RNAi导向的异染色蛋白围绕着中央动态域是促进CENP-A ((Cnp1) 和动态组装的必要条件.
- 表明Clr4,Dicer,Chp1和Swi6是建立CENP-A(Cnp1) 染色体在新的中心基序列上所需的.
- 发现,一旦组装,CENP-A(Cnp1) 染色体是表观遗传传播独立于异性染色体.
结论:
- 集中式RNAi导向的异色染色素在CENP-A染色素和动态细胞组合的初始建立中发挥着关键作用.
- 这项研究揭示了中间体RNAi在中心体标识的表观遗传调节中的保留作用.
- 这些发现突出了RNAi在指导中心色素的表观遗传中的新功能.
相关概念视频
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...
02:38Heterochromatin
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...
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...
03:17Inheritance of Chromatin Structures
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying DNA...
01:01Euchromatin
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...
01:01Euchromatin
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...