Alternative splicing of Mef2c promoted by Fox-1 during neural differentiation in P19 cells
Alternative splicing of Mef2c promoted by Fox-1 during neural differentiation in P19 cells
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DOI：
10.1111/j.1365-2443.2009.01378.x
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发表时间：
2010-03-01
期刊：
影响因子：
2.1
通讯作者：
Suzuki, Hitoshi
中科院分区：
文献类型：
--
作者：
Ab Hakim, Nor Hakimah;Kounishi, Toshiki;Suzuki, Hitoshi
Mef 2c蛋白是参与肌肉分化和突触形成的MADS盒型转录因子之一。此前有报道称，Mef 2c基因负责三种选择性剪接调控。在这里，我们研究了Mef 2c的选择性剪接变体在P19细胞的神经分化过程中和在P19克隆6（P19 CL 6）的心肌分化过程中。我们检测到两个Mef 2c mRNA亚型，使用外显子α 1与和没有在外显子10的γ区域，主要产生于未成熟的P19细胞。值得注意的是，含有外显子β的Mef 2c亚型特异性地出现在神经细胞阶段。由于大多数转录本在神经细胞阶段和大脑中含有外显子β，这表明外显子β的选择性剪接受到高度调节。在已知的调节因子中，Fox-1在神经细胞阶段特异性表达，与Mef 2c外显子β相关。在使用Mef 2c β小基因的转染实验中，Fox-1促进外显子β包含。此外，我们发现该启动需要位于外显子β的相邻内含子中的Fox-1和GCAUG序列的RNA结合活性。总之，我们的结果表明，Fox-1，在神经细胞阶段，特别是表达，促进Mef 2c外显子β通过GCAUG列入。
Mef2c protein is one of the MADS-box type transcription factors involved in muscular differentiation and synaptic formation. Previously, it has been reported that the Mef2c gene is responsible for three alternative splicing regulations. Here, we investigated the alternative splicing variants of Mef2c during neural differentiation of P19 cells and during cardio muscular differentiation of P19 clone 6 (P19CL6). We detected that two Mef2c mRNA isoforms, using exon alpha 1 with and without the gamma region at exon 10, are mainly produced in immature P19 cells. Remarkably, Mef2c isoforms containing exon beta specifically appeared in the neural cell stage. Because most transcripts contain exon beta in the neural cell stage and in the brain, this suggests that the alternative splicing of exon beta is highly regulated. Among known regulators, Fox-1 was specifically expressed in the neural cell stage in correlation with Mef2c exon beta. Fox-1 promoted exon beta inclusion in transfection experiments using Mef2c beta minigene. Moreover, we found that the promotion required RNA-binding activity of Fox-1 and GCAUG sequence located in adjacent intron of exon beta. Taken together, our results suggest that Fox-1, expressed specifically in the neural cell stage, promoted Mef2c exon beta inclusion via the GCAUG.