サイト固有のRループは,CGGの繰り返し収縮と脆弱なX遺伝子の再活性化を誘導する
Hun-Goo Lee1, Sachiko Imaichi1, Elizabeth Kraeutler1
1Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Genetics, Harvard Medical School, Boston, MA 02114, USA.
Cell
|May 20, 2023
まとめ
研究者らは,MEKとBRAF阻害剤は,CGGの繰り返し拡大を収縮させ,脆弱なX症候群 (FXS) を引き起こすことを発見した. このアプローチはFMR1遺伝子を再活性化し,FMRPタンパク質の生成を回復し,FXSの将来の治療の可能性を提供します.
科学分野:
- 遺伝学
- 神経科学
- 分子生物学
背景:
- 脆いX症候群 (FXS) は自閉症スペクトル障害の主な原因である.
- FXSは,大きなCGGの繰り返し拡大によるFMR1遺伝子のエピジェネティックサイレンスから生じる.
- FXSの現在の治療法は限られており,新しい治療戦略が必要である.
研究 の 目的:
- 固有の修復メカニズムをターゲットにすることで,FXSに対する新しい治療アプローチを調査する.
- FXSの遺伝的欠陥を逆転させる 条件と化合物を特定する
- FMR1遺伝子の発現と FMRPタンパク質の生成を回復する.
主な方法:
- FMR1の再活性化を促進する化合物のスクリーニング
- 脆弱X症候群の 細胞モデルを使って
- DNA脱メチル化とRループ形成を含む,繰り返し収縮と遺伝子再活性化に伴う分子機構を調査する.
主要な成果:
- MEKとBRAFの阻害剤は,細胞モデルでCGGの重複収縮を誘導することが確認された.
- これらの阻害剤は,FMR1遺伝子の完全な再活性化をもたらしました.
- このメカニズムは DNA 脱メチル化と R ループ形成を伴うもので,内生的な DNA 修復経路を駆使して再発を抑制する.
- FMR1に特異的であり,FMRPのタンパク質合成が回復した.
結論:
- MEKとBRAF阻害剤を含むFXSの新しい治療戦略が特定されました.
- このアプローチは,内生的なDNA修復メカニズムを活用して,FXSの遺伝的欠陥を修正します.
- FMR1機能を回復させることで,脆弱X症候群に対する有望な治療の可能性を示しています.
関連する概念動画
Conservative Site-specific Recombination and Phase Variation
6.0K
Because the DNA segments are cut and reorganized in a direction-specific manner, site-specific recombination has emerged as an efficient genetic engineering technique. Flippase and Cyclization recombinases or Flp and Cre, respectively, are two members of the tyrosine recombinase family derived from bacteriophages, that are used to mediate site-specific DNA insertions, deletions, and targeted expression of proteins in mammalian cell lines.
The recognition sites for Cre recombinase called LoxP...
The recognition sites for Cre recombinase called LoxP...
6.0K
Restarting Stalled Replication Forks
5.9K
DNA replication is initiated at sites containing predefined DNA sequences known as origins of replication. DNA is unwound at these sites by the minichromosome maintenance (MCM) helicase and other factors such as Cdc45 and the associated GINS complex.The unwound single strands are protected by replication protein A (RPA) until DNA polymerase starts synthesizing DNA at the 5’ end of the strand in the same direction as the replication fork. To prevent the replication fork from falling apart,...
5.9K
Inheritance of Chromatin Structures
6.3K
Epigenetics is the study of inherited changes in a cell's phenotype without changing the DNA sequences. It provides a form of memory for the differential gene expression pattern to maintain cell lineage, position-effect variegation, dosage compensation, and maintenance of chromatin structures such as telomeres and centromeres. For example, the structure and location of the centromere on chromosomes are epigenetically inherited. Its functionality is not dictated or ensured by the underlying...
6.3K
Long-patch Base Excision Repair
7.1K
Since the discovery of the two BER pathways, there has been a debate about how a cell chooses one pathway over the other and the factors determining this selection. Numerous in vitro experiments have pointed out multiple determinants for the sub-pathway selection. These are:
7.1K
Non-LTR Retrotransposons
11.6K
As the name suggests, non-LTR retrotransposons lack the long terminal repeats characteristic of the LTR retrotransposons. Additionally, both LTR and non-LTR retrotransposons use distinct mechanisms of mobilization. Non-LTR retrotransposons are further divided into two classes - Long interspersed nuclear elements (LINEs) and short interspersed nuclear elements (SINEs), both of which occur abundantly in most mammals, including humans. Some of the active non-LTR retrotransposons in humans are L1...
11.6K
Crossing Over
4.5K
Crossing over is the exchange of genetic information between homologous chromosomes during prophase I of meiosis I. Genetic recombination gives rise to allelic diversity in the newly formed daughter cells. In humans, crossing over produces genetically distinct haploid egg and sperm cells that undergo fertilization to produce unique offspring. Before cell division starts, the germ cell’s chromosome(s) undergo duplication in the S phase of the cell cycle. As the cells enter prophase I,...
4.5K


