保守组装和分离的核细胞组合组合和核细胞组合组合的核细胞组合组合和分离的核细胞组合组合和分离
Cell
|November 1, 1977
概括
在DNA复制过程中,新的基因素八基组组合得很保守,不会混合旧和新蛋白质. 通过多个细胞代,这种保守的基因素八聚体分离得到了维持.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 细胞生物学 细胞生物学
背景情况:
- 基因组是基本的蛋白质,它们将DNA包装成核体,形成染色体.
- 了解组织蛋白组合和分离对于细胞分裂和遗传至关重要.
- 在DNA复制过程中,基因组动态的精确机制仍然是活跃研究的领域.
研究的目的:
- 为了研究组装过程的新组织蛋白进入核细胞.
- 为了确定DNA复制过程中老基因组是如何分离的.
- 为了分析细胞几代的基因素八合体的稳定性和分离模式.
主要方法:
- 在肉肉细胞培养物中用密集氨基酸和3H-氨酸标记组织蛋白.
- 从核细胞体中分离和交叉链接素八合体.
- 密度梯度沉积平衡分析使用酸-瓜尼迪尼-HCI梯度.
主要成果:
- 新合成的希斯八聚体以保守的方式组合在一起,而不与先前存在的希斯混合.
- 密度高的希斯八基体在3-4个细胞代中表现出稳定性.
- 有证据表明,邻近的 histone 八合体是同时合成的.
- 在2-3代的时间里观察到旧和新素八基体的保守分离.
结论:
- 在DNA复制过程中组建 histone octamer 是一个保守的过程.
- 希斯八聚体是稳定的实体,在细胞分裂过程中保守地分离.
- 这些发现提供了有关维护染色质结构和表观遗传信息的见解.
相关概念视频
02:10The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
The paradox
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their main responsibility is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. While on the other hand, they must allow polymerase enzymes to access DNA...
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...
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...
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...
01:12The Nucleosome Core Particle
Nucleosomes are the DNA-histone complex, where the DNA strand is wound around the histone core. The histone core is an octamer containing two copies of H2A, H2B, H3, and H4 histone proteins.
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...
Nucleosomes, paradoxically, perform two opposite functions simultaneously. On the one hand, their primary aim is to protect the delicate DNA strands from physical damage and help achieve a higher compaction ratio. On the other hand, they must allow polymerase enzymes to access histone-bound DNA during...