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.
F5 编码凝血因子 V(factor V),这是一种血浆糖蛋白,可经蛋白水解激活为因子 Va,并在凝血酶原酶复合体(prothrombinase complex)中作为因子 Xa 的辅因子,加速凝血酶生成与纤维蛋白血栓形成。因子 V 的活性受限于有限蛋白水解调控,并可被活化蛋白 C 失活,从而使 F5 与蛋白酶级联反应、磷脂依赖的膜组装以及止血过程的反馈调控相联系。F5 的遗传性或获得性改变可影响凝血动力学,常在血栓形成与出血表型研究中被关注,包括因子 V 缺乏症以及因子 V Leiden 相关的活化蛋白 C 抵抗。因而,F5 常被用于解析凝血网络的结构特征、内皮细胞与血小板相关的促凝活性,以及与炎症信号之间的相互作用。
Factor V 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 F5 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F5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F5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。