特殊なヌクレオソームには"ポイント"が作られています
Weiguo Zhang1, Barbara G Mellone, Gary H Karpen
1Department of Genome and Computational Biology, Lawrence Berkeley National Laboratory, MS 84-171, 1 Cyclotron Road, Berkeley, CA 94720, USA.
Cell
|June 19, 2007
まとめ
非ヒストンタンパク質Scm3は,ヒストンH3変異体Cse4を芽生えた酵母中のセントロメアに誘導するために重要である. Scm3は独特のクロマチンの成分を形成し,セントロメア組立とクロマチンの機能に影響を与えます.
科学分野:
- 分子生物学は分子生物学である.
- クロマチンの生物学
- イースト遺伝学 イースト遺伝学
背景:
- セントロメアは,細胞分裂中の染色体分離に不可欠です.
- ヒストンH3変種Cse4は,セントロメア特異的な核細胞体の重要な構成要素である.
- セントロメアへのCse4の徴集の正確なメカニズムは,まだ完全に理解されていません.
研究 の 目的:
- Cse4.4のセントロメリックリクルートメントにおける非ヒストンタンパク質Scm3の役割を明らかにする.
- Scm3とCse4.4を含むクロマチン複合体の組成を特徴づけること.
主な方法:
- 芽生える酵母をモデル生物として利用した.
- タンパク質とタンパク質の相互作用とクロマチンの組立を研究した.
- セントロメリッククロマチンの組成を分析した.
主要な成果:
- セントロメアへのCse4の徴集にScm3が不可欠であることを示した.
- Scm3がCse4:ヒストンH4テトラマーとクロマチンの成分を形成することを示した.
- この複合体はヒストーンH2A/H2Bが欠けているように見える.
結論:
- Scm3は,Cse4の中心部局所化の経路において重要な役割を果たしています.
- この発見は,セントロメアにおける新しい染色体構造を明らかにし,染色体組織と機能に関する私たちの理解に影響を与えています.
関連する概念動画
01:19The Nucleosome
Human DNA is almost two meters long. However, it is compressed inside a tiny nucleus measuring only a few microns in diameter. To make this degree of compaction possible, DNA is organized into several sequential levels so that it can fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
In a chromosome, DNA is wound twice around a protein complex called a histone octamer core, which consists of 8 histone proteins. This...
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
02:33The Nucleosome
DNA in a human cell is almost 2m long and it is packed inside a tiny nucleus that is only a few microns in diameter. The level of compaction of DNA inside the nucleus is astonishing. It is organized into several sequentially higher levels of compaction to fit into such a tiny space. The most compact form of DNA is a chromosome that can be seen under a microscope in a dividing cell.
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
DNA is wound twice around a protein complex called histone core, that consist of 8 histone proteins. This complex...
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...
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...
02:30Histone 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...