APOBEC-1 dependent cytidine to uridine editing of apolipoprotein B RNA in yeast

Cytidine to uridine editing of apolipoprotein B (apoB) mRNA requires the cytidine deaminase APOBEC-1 as well as a tripartite sequence motif flanking a target cytidine in apoB mRNA and an undefined number of auxiliary proteins that mediate RNA recognition and determine site-specific editing. Yeast engineered to express APOBEC-1 and apoB mRNA supported editing under conditions of late log phase growth and stationary phase. The cis-acting sequence requirements and the intracellular distribution of APOBEC-1 in yeast were similar to those described in mammalian cells. These findings suggest that auxiliary protein functions necessary for the assembly of editing complexes, or ‘editosomes’, are expressed in yeast and that the distribution of editing activity is to the cell nucleus.

载脂蛋白B（apolipoprotein B, apoB）mRNA的胞苷-尿苷编辑，依赖胞苷脱氨酶APOBEC-1，同时还需要apoB mRNA中靶胞苷两侧的三单元序列基序，以及若干介导RNA识别并决定编辑位点特异性的辅助蛋白（数量尚未明确）。经基因工程改造以表达APOBEC-1和apoB mRNA的酵母，在对数生长期后期及静止期的培养条件下可支持编辑反应。酵母中APOBEC-1的顺式作用序列需求及其细胞内分布特征，与哺乳动物细胞中已报道的结果高度相似。上述研究结果表明，酵母可表达编辑复合物（或称“编辑体”，editosomes）组装所必需的辅助蛋白功能，且编辑活性定位于细胞核。