The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
Cas9n Nickase gRNA Plasmid Targeting: Dual gRNA plasmids create single-strand nicks at precise DNA sequences for efficient genome editing using Cas9n Nickase.
This image illustrates the Cas9n Nickase mechanism used for precise genome editing. Two plasmids (Plasmid 1 and Plasmid 2) are shown, each containing a targeted DNA sequence. The system utilizes single-guide RNAs (sgRNA) to direct Cas9n Nickase to specific genomic locations, represented by the blue and pink DNA strands. The sgRNA scaffold aids in guiding Cas9n to the 20 nucleotide (nt) target sequence on the DNA. Cas9n makes single-strand cuts at NCC and NGG sites, enabling precise gene modifications without creating double-strand breaks.
The Double Nickase Plasmid features a U6 promoter for sgRNA expression, a 20 nt targeting sequence, and a gRNA scaffold to guide Cas9n. It includes a CBh promoter for Cas9n (D10A) and puromycin resistance, GFP for transfection verification, and nuclear localization signals (NLS). The 2A peptide allows co-expression of Cas9n and Puro from a single promoter, enabling precise genome editing with reduced off-target effects.
CHD1(chromodomain helicase DNA binding protein 1,染色质结构域解旋酶 DNA 结合蛋白 1)是一种 ATP 依赖性的染色质重塑因子,可通过其染色质结构域识别甲基化的组蛋白标记,并通过重新定位核小体来调控染色质可及性。它参与支持转录调控、RNA 聚合酶 II 的延伸过程,并维持活跃启动子及基因体区域的开放染色质状态,因此与 DNA 复制、DNA 损伤应答和基因组稳定性等过程相关。CHD1 的功能与影响细胞身份与分化程序的染色质组织及表观遗传调控通路相互交织。CHD1 活性或基因组状态的改变与转录失衡和基因组不稳定等表型相关,这些表型与癌症生物学及其他由染色质驱动的疾病机制具有相关性。
CHD1 双切酶质粒(h)由一对匹配的质粒组成,专为在 human 细胞系中对 CHD1 位点进行高特异性编辑而设计。每个质粒分别表达Cas9 D10A切口酶和针对CHD1内不同DNA链的独特sgRNA。当这两种切口酶被引导至相邻但位于DNA链相反侧的位点时,会产生错位的单链切口,从而共同形成错位双链断裂,这需要两个引导RNA在靶位点上协同发挥作用。由此产生的DNA断裂通过内源性细胞修复途径(最常见的是非同源末端连接(NHEJ))得到修复,从而导致插入或缺失,进而破坏CHD1的功能。通过要求双sgRNA在靶位点结合,双切口方法提高了编辑特异性,并为需要对靶向精度进行额外控制的应用提供了互补的CRISPR策略。