Alu elements, the most abundant retrotransposed elements in the human genome, are commonly located in introns and affect alternative splicing. We previously showed that an intronic antisense Alu element enhanced alternative splicing in a minigene model. The RNA splicing experiment was performed using a minigene consisting of exons 9–11 of ACAT1 with an antisense AluSx inserted into intron 10 in a pCAGGS vector. Here, we explored the sequence in the intronic antisense AluSx that affects downstream exon skipping. Our RNA splicing analysis with antisense AluSx deletion mutants confirmed a short sequence of 16 bp within the right arm of antisense AluSx that resulted in exon skipping. Our findings help clarify the mechanism of RNA splicing by Alu elements.

Alu元件是人类基因组中最丰富的逆转录元件，通常位于内含子中并影响选择性剪接。我们之前表明，内含子反义Alu元素增强了小基因模型中的选择性剪接。使用由ACAT1的外显子 9-11 组成的小基因进行 RNA 剪接实验，反义Alu Sx 插入到 pCAGGS 载体的内含子 10 中。在这里，我们探索了影响下游外显子跳跃的内含子反义Alu Sx 中的序列。我们对反义Alu Sx 缺失突变体的RNA 剪接分析证实了反义Alu右臂内的 16 bp 短序列Sx 导致外显子跳跃。我们的发现有助于阐明Alu元素对 RNA 剪接的机制。