Cas9は,CRISPR-Cas適応の際に機能的なウイルスの標的を指定しています
Robert Heler1, Poulami Samai1, Joshua W Modell1
1Laboratory of Bacteriology, The Rockefeller University, 1230 York Avenue, New York, New York 10065, USA.
Nature
|February 25, 2015
まとめ
Cas9タンパク質は,バクテリアの適応免疫に不可欠なスペーサー獲得プロセス中に,PAMと呼ばれる特定のDNA配列を認識します. この発見は,プロカリオット免疫記憶の発達におけるCas9の新たな役割を明らかにしています.
科学分野:
- 微生物学 微生物学とは
- 分子生物学は分子生物学である.
- 免疫学 免疫学とは
背景:
- プロカリオットは,CRISPR-Casシステムを通じてウイルスに対する適応免疫を持っています.
- CRISPR-Casシステムは,小さなRNA分子を用いて,Cas核酸を誘導して,ウイルスのDNAを標的にします.
- Streptococcus pyogenes Cas9は,DNAの分裂のためにプロトスペーサー隣接モチーフ (PAM) を必要とします.
研究 の 目的:
- CRISPR-Casシステムにおけるスペーサー取得のメカニズムを調査する.
- Cas9が取得中のスペーサー配列の選択に作用するかどうかを判断する.
- プロカリオット免疫記憶の生成におけるPAM認識の役割を明らかにする.
主な方法:
- PAM認識を変更するためにCas9アレルの遺伝子操作.
- Streptococcus pyogenesにおけるスペーサー獲得特異性の分析.
- コイムノプレシピテーションは,採取機構内のタンパク質の相互作用を研究するための測定法です.
主要な成果:
- Cas9は,スペーサー取得中にPAM配列を直接認識します.
- Cas9 修正されたスペーサー取得特異性の PAM 認識モチーフの変更または削除.
- Cas9は他の取得タンパク質 (Cas1, Cas2, Csn2) と相互作用して,PAM特異性を授与する.
結論:
- Cas9は,新しいスペーサーの獲得中にPAM配列を認識する新しい機能を持っています.
- Cas9によるこのPAM認識は,プロカリオット適応免疫の特異性にとって不可欠である.
- この研究は,プロカリオットにおける免疫学的記憶の生成のための新しいメカニズムを確立しています.
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