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.
ABCD4 编码一种与 ATP 结合盒(ABC)转运蛋白相关的蛋白质,其在溶酶体内钴胺素(维生素 B12)处理过程中发挥作用:通过促进钴胺素从溶酶体输出到细胞质,使其得以进一步转化为活性辅因子腺苷钴胺素(adenosylcobalamin)和甲基钴胺素(methylcobalamin)。借由这一功能,ABCD4 支持一碳代谢以及依赖蛋氨酸合成酶和甲基丙二酰辅酶 A 变位酶活性的线粒体相关通路,从而影响甲基化平衡与能量代谢。ABCD4 功能受损与钴胺素代谢的先天性错误有关,其生化特征包括再甲基化受损和/或丙酸代谢(丙酸盐分解)障碍。因此,ABCD4 常在溶酶体转运、辅因子稳态以及代谢应激反应等研究背景下被关注。
ABCD4 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 ABCD4 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ABCD4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ABCD4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。