核孔复合体在静音端粒染色素组织中的作用
V Galy1, J C Olivo-Marin, H Scherthan
1Laboratoire de Biologie Cellulaire du Noyau, Institut Pasteur, CNRS URA 1773, Paris, France.
Nature
|January 19, 2000
概括
核孔复合扩展,Mlp1和Mlp2,在酵母中组织周核色素域. 这些结构将端粒和Yku70连接到核外围,调节基因抑制和DNA修复.
科学领域:
- 细胞生物学 细胞生物学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 核中的染色体组织和空间布局对其功能调节至关重要.
- 在酵母中,周核色素域与转录抑制有关,并以周核端粒集群为特征.
- 已知Yku70/Yku80异构体结合端粒,并参与DNA双链断裂修复和端粒维护,但其在周核静态域的结构组织中的作用尚不清楚.
研究的目的:
- 为了阐明酵母中周核静音域的结构基础.
- 确定负责周核染色体结构和功能组织的蛋白质.
- 了解将染色质与核外连接的机制及其在基因调节中的作用.
主要方法:
- 研究了Mlp1和Mlp2 (保存的TPR同类物) 在周核染色体组织中的作用.
- 评估了MLP2删除对双链断裂修复的影响.
- 分析了MLP1和MLP2双删除对端粒聚类和端粒基因抑制的影响.
- 研究了Mlp2和Yku70.0之间的相互作用.
- 研究了Mlp2-Yku70复合体通过Nup145.5与核孔复合体的对接.
主要成果:
- 核孔复合扩展,Mlp1和Mlp2,负责周核色素的结构和功能组织.
- 丢失MLP2显著损害了双链断裂的修复.
- 删除MLP1和MLP2会破坏周核端粒聚类,并缓解端粒基因抑制.
- Mlp2在物理上将Yku70与核外围连接起来,建立了染色质-核外连接.
- 这种链接通过核蛋白Nup145.5通过核孔复合体与核孔复合体挂.
结论:
- 核孔复合扩展 (Mlp1/Mlp2) 是周核色素域的关键组织者.
- 这些结构在DNA修复,端粒定位和调节端粒中的基因沉默中发挥着关键作用.
- 通过与Yku70和Nup145的相互作用,Mlp蛋白在染色质和核外之间建立了结构联系,组织了参与染色质代谢的核子域.
相关概念视频
02:54Nucleosome Remodeling
Nucleosomes are the basic units of chromatin compaction. Each nucleosome consists of the DNA bound tightly around a histone core, which makes the DNA inaccessible to DNA binding proteins such as DNA polymerase and RNA polymerase. Hence, the fundamental problem is to ensure access to DNA when appropriate, despite the compact and protective chromatin structure.
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
Nucleosome remodeling complex
Eukaryotic cells have specialized enzymes called ATP-dependent nucleosome remodeling enzymes. These enzymes...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
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...
02:21Chromatin Packaging
Each human somatic cell contains 6 billion base-pairs of DNA. Each base-pair is 0.34 nm long, which means that each diploid cell contains a staggering 2 meters of DNA. How is such a long DNA strand packed inside a nucleus measuring only 10 - 20 microns in diameter?
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
The chromatin
In combination with specialized DNA binding protein called Histones, the DNA double helix forms a compact DNA: protein complex called chromatin. The chromatin itself is further compacted into higher-order structures.
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...
01:32Chromatin Packaging
Each human somatic cell contains 6 billion base pairs of DNA. Each base pair is 0.34 nm long, meaning each diploid cell contains a staggering 2 meters of DNA. This long DNA strand is packed inside a nucleus measuring only 10-20 microns in diameter with the help of specialized DNA-binding proteins called histones. Together they form a compact DNA-protein complex called chromatin. The chromatin is further compacted into higher-order structures. The highest level of compaction is achieved during...