CENP-T-W-S-Xは,ヒストンのような折りたたみを持つユニークなセントロメリッククロマチン構造を形成します
Tatsuya Nishino1, Kozo Takeuchi, Karen E Gascoigne
1Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies (SOKENDAI), Mishima, Shizuoka 411-8540, Japan.
Cell
|February 7, 2012
まとめ
CENP-T-W-S-X複合体は,キネトコア組立に不可欠な,ニュクレオソームのようなユニークな構造を形成します. この複合体は,正確な染色体分離に不可欠なDNAを結合し,スーパーコイルします.
科学分野:
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- 正確な染色体分離は,特定の染色体部位に集まるキネトコア複合体に依存する.
- キネトコアを位置付けるDNAとタンパク質の相互作用を理解することは,重要な研究目標です.
研究 の 目的:
- キネトコア形成におけるCENP-T-W-S-X複合体の構造と機能を明らかにする.
- この複合体のDNA結合とスーパーコーリング活動を定義する.
主な方法:
- 個々の複合体の高解像度構造分析とCENP-T-W-S-Xヘテロテトラマー.
- DNAの結合とスーパーコーリングを評価するためのインビトロ生化学測定法.
- キネトコア組立を評価するために突然変異体を用いたインビボ研究.
主要な成果:
- CENP-T-WとCENP-S-X複合体は,安定したCENP-T-W-S-Xヘテロテトラマーに組み合わされます.
- ヘテロテトラメアは,正規のヒストンと構造的に類似しており,DNAを結合/スーパーコイルする.
- ヘテロテトラメリゼーションやDNA接触を阻害する突然変異は,DNAの結合,スーパーコーリング,および体内のキネトコア組成を損なう.
結論:
- CENP-T-W-S-X複合体は,ニュクレオソームのような構造として機能し,キネトコア組立のためのDNA相互作用を媒介する.
- この発見は",ヒストンコード"の概念を拡張し,DNA組織に関与する非正規のタンパク質を含める.
関連する概念動画
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...
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...
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...
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...