AG-dependent 3′-splice sites are predisposed to aberrant splicing due to a mutation at the first nucleotide of an exon
AG-dependent 3′-splice sites are predisposed to aberrant splicing due to a mutation at the first nucleotide of an exon
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DOI：
10.1093/nar/gkr026
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发表时间：
2011-05-01
影响因子：
14.9
通讯作者：
Ohno, Kinji
中科院分区：
文献类型：
--
作者：
Fu, Yuan;Masuda, Akio;Ohno, Kinji
在前 mRNA 剪接中，3' 剪接位点的保守 AG/G 被 U2AF(35) 识别。废除外显子第一个位置处的 G 核苷酸 (E(+1)) 的致病突变会导致 GH1、FECH 和 EYA1 中的外显子跳跃，但不会导致 LPL 或 HEXA 中的外显子跳跃。 U2AF(35) 的敲低增强了 GH1 和 FECH 中的外显子跳跃。 RNA-EMSA显示野生型FECH需要U2AF(35)，但野生型LPL不需要。 GH1、FECH、EYA1、LPL和HEXA的多嘧啶片段中的一系列人工突变揭示，在E(+1)处存在突变的情况下，需要至少10-15个嘧啶片段来确保正常剪接。对 E(+1) 处其他九个致病突变的分析检测到五个剪接突变。我们的研究表明，需要 U2AF(35) 进行剪接体组装的 AG 依赖性 3' 剪接位点的突变会导致外显子跳跃，而不需要 U2AF(35) 的 AG 独立 3' 剪接位点的突变会产生正常剪接。我们在 E(+1) 的致病突变中分析了 3' 剪接位点的 AG 依赖性，这可能有助于识别 E(+1) 处尚未识别的剪接突变。
In pre-mRNA splicing, a conserved AG/G at the 3'-splice site is recognized by U2AF(35). A disease-causing mutation abrogating the G nucleotide at the first position of an exon (E(+1)) causes exon skipping in GH1, FECH and EYA1, but not in LPL or HEXA. Knockdown of U2AF(35) enhanced exon skipping in GH1 and FECH. RNA-EMSA revealed that wild-type FECH requires U2AF(35) but wild-type LPL does not. A series of artificial mutations in the polypyrimidine tracts of GH1, FECH, EYA1, LPL and HEXA disclosed that a stretch of at least 10-15 pyrimidines is required to ensure normal splicing in the presence of a mutation at E(+1). Analysis of nine other disease-causing mutations at E(+1) detected five splicing mutations. Our studies suggest that a mutation at the AG-dependent 3'-splice site that requires U2AF(35) for spliceosome assembly causes exon skipping, whereas one at the AG-independent 3'-splice site that does not require U2AF(35) gives rise to normal splicing. The AG-dependence of the 3'-splice site that we analyzed in disease-causing mutations at E(+1) potentially helps identify yet unrecognized splicing mutations at E(+1).