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.
FUT7 编码 α1,3-岩藻糖基转移酶 VII(FucT-VII),这是一种定位于高尔基体的糖基转移酶,催化合成唾液酸化 Lewis X(sialyl Lewis X)及相关岩藻糖化糖链所需的末端岩藻糖基化步骤。该酶活性通过在糖蛋白和糖脂上形成具有功能的选择素(selectin)配体,支撑炎症过程中白细胞的滚动黏附与迁移,因此在白细胞黏附生物学中处于核心地位。FUT7 介导的糖基化与更广泛的糖链生物合成通路相互交织,共同塑造细胞—细胞识别、受体信号传导以及免疫细胞表面糖链结构。FUT7 表达或岩藻糖基化模式的改变与炎症反应失调以及肿瘤相关的糖链重塑有关,因此它也是研究黏附机制与糖链—免疫相互作用的一个有价值靶点。
FucT-VII 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 FUT7 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FUT7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FUT7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。