研究發現改造RNA二級結構可以提高CRISPR特異性
作者:
小柯機器人發布時間:2019/7/8 16:28:41
改造RNA的二級結構可以提高CRISPR系統的特異性,這一成果由杜克大學Charles A. Gersbach團隊取得。 該成果發表在2019年6月出版的國際學術期刊《Nature Biotechnology》上。
課題組研究人員表示,在單導向RNA的間隔區域(hp-sgRNAs)改造一個髮夾結構的RNA二級結構,與各種CRISPR效應物結合使用,可以提高几個數量級的特異性。該團隊首先證明設計hp-sgRNAs,根據化膿性鏈球菌來源的Cas9(SpCas9),可以調節反式激活因子的活性。然後課題組表明hp-sgRNAs可以增加基因編輯的特異性在五個不同Cas9或Cas12a變體中。他們的結果表明RNA二級結構是一個基本參數,可以調節不同的CRISPR系統的活性。
據介紹,CRISPR (簇狀規則間隔短回文重複序列)系統已經廣泛應用於基礎科學、生物技術、基因和細胞治療。在某些情況下,些細菌核酸酶出現了脫靶效應。這對於應用治療程序的創建是潛在的危險,還可能會影響生物研究的最終結果。因此,提高這些核酸酶的精確度具有廣泛的意義。
附:英文原文
Title: Increasing the specificity of CRISPR systems with engineered RNA secondary structures
Author: D. Dewran Kocak, Eric A. Josephs, Vidit Bhandarkar, Shaunak S. Adkar, Jennifer B. Kwon, Charles A. Gersbach
Issue&Volume: Volume 37 Issue 6, June 2019
Abstract: CRISPR (clustered regularly interspaced short palindromic repeat) systems have been broadly adopted for basic science, biotechnology, and gene and cell therapy. In some cases, these bacterial nucleases have demonstrated off-target activity. This creates a potential hazard for therapeutic applications and could confound results in biological research. Therefore, improving the precision of these nucleases is of broad interest. Here we show that engineering a hairpin secondary structure onto the spacer region of single guide RNAs (hp-sgRNAs) can increase specificity by several orders of magnitude when combined with various CRISPR effectors. We first demonstrate that designed hp-sgRNAs can tune the activity of a transactivator based on Cas9 from Streptococcus pyogenes (SpCas9). We then show that hp-sgRNAs increase the specificity of gene editing using five different Cas9 or Cas12a variants. Our results demonstrate that RNA secondary structure is a fundamental parameter that can tune the activity of diverse CRISPR systems.
DOI: 10.1038/s41587-019-0095-1
Source:https://www.nature.com/articles/s41587-019-0095-1