コヘシンは,転写,CTCF,Waplによって哺乳類のゲノムに位置づけられる
Georg A Busslinger1, Roman R Stocsits1, Petra van der Lelij1
1Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus-Vienna-Biocenter 1, A-1030 Vienna, Austria.
Nature
|April 21, 2017
まとめ
哺乳類のゲノム組織は,CCCTC結合因子 (CTCF) とコヘシンに依存しています. この研究は,転写がコヘシンを移動させ,CTCFの位置と遺伝子調節に影響を与えることを明らかにしています.
科学分野:
- ゲノミクス
- 分子生物学
- エピジェネティクス
背景:
- 哺乳類のゲノムはCTCFとコヘシンによってクロマチンループと トポロジカルに関連したドメインに分類される.
- CTCF結合部位はコヘシン媒介の長距離染色体相互作用に不可欠ですが,コヘシン徴用メカニズムはまだ不明です.
研究 の 目的:
- 哺乳類のゲノムにおけるコヘシン分布を制御する要因を調査する.
- トランスクリプション,CTCF,およびWaplがコヘシンダイナミクスと局所化における役割を明らかにする.
主な方法:
- CTCFが枯渇したマウスの線維芽細胞を用いて,コヘシン行動を観察した.
- CTCFとWaplの両方の不在でコヘシン分布を分析した.
- コヘシン局所化に対する変化した遺伝子発現の影響を調査した.
主要な成果:
- Cohesinは,CTCFが枯渇した細胞のCTCF部位に結合せず,代わりに活性遺伝子転写開始部位に蓄積する.
- CTCFとWaplが存在しない場合,コヘシンが活性遺伝子の3'-端に"島"を形成し,遺伝子の発現レベルに影響を与えます.
- 酵母に類似した長いDNA距離におけるコヘシンの転写媒介による転位が観察された.
結論:
- 転写は哺乳類のコヘシン移転に重要な役割を果たし,CTCFの位置づけに寄与する.
- 活性遺伝子は,転写媒介による転位またはWapl媒介による放出によってコヘシンから放出され,遺伝子調節に影響を与えます.
関連する概念動画
Cohesins
5.8K
Cohesin protein complexes are a molecular glue that holds two sister chromatids together. They play an important role both in mitosis and meiosis. In mitosis, all cohesin complexes present on the chromosomes are removed before the start of the anaphase stage.
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
Cohesin complexes in Meiotic Division
Meiosis involves two distinct rounds of chromosomal segregation and cell divisions— Meiosis I followed by Meiosis II – producing four daughter cells. Meiosis I includes the separation of...
5.8K
Chromatin Position Affects Gene Expression
25.1K
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the...
25.1K
Condensins
4.8K
Condensins are large protein complexes that use ATP to fuel the assembly of chromosomes during mitosis. They transform the tangled, shapeless mass of post-interphase DNA into individualized chromosomes by compacting, organizing, and segregating chromosomal DNA.
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
The plant and animal cells contain two types of condensin complexes—condensin I and condensin II. Both complexes have five subunits: two SMC (Structural Maintenance of Chromosomes) subunits, a kleisin subunit, and two HEAT-repeat...
4.8K
Separation of Sister Chromatids
4.6K
At the transition from prophase to metaphase, there is a reduction in cohesion along the chromosomal arms, resulting in the resolution of sister chromatids. However, residual cohesin connections remain to hold the sister chromatids together until the transition from metaphase to anaphase. The residual connection prevents any premature separation of sister chromatids, blocking the risks of aneuploidy within the daughter cells.
At the onset of anaphase, separase, a proteolytic enzyme, is...
At the onset of anaphase, separase, a proteolytic enzyme, is...
4.6K
Histone Variants at the Centromere
5.2K
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...
5.2K
Position-effect Variegation
7.2K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.2K


