PDF(Pubmed)
Abstract：
Spinal muscular atrophy (SMA) genes, SMN1 and SMN2 (hereinafter referred to as SMN1/2), produce multiple circular RNAs (circRNAs), including C2A-2B-3-4 that encompasses early exons 2A, 2B, 3 and 4. C2A-2B-3-4 is a universally and abundantly expressed circRNA of SMN1/2. Here we report the transcriptome- and proteome-wide effects of overexpression of C2A-2B-3-4 in inducible HEK293 cells. Our RNA-Seq analysis revealed altered expression of ~ 15% genes (4172 genes) by C2A-2B-3-4. About half of the affected genes by C2A-2B-3-4 remained unaffected by L2A-2B-3-4, a linear transcript encompassing exons 2A, 2B, 3 and 4 of SMN1/2. These findings underscore the unique role of the structural context of C2A-2B-3-4 in gene regulation. A surprisingly high number of upregulated genes by C2A-2B-3-4 were located on chromosomes 4 and 7, whereas many of the downregulated genes were located on chromosomes 10 and X. Supporting a cross-regulation of SMN1/2 transcripts, C2A-2B-3-4 and L2A-2B-3-4 upregulated and downregulated SMN1/2 mRNAs, respectively. Proteome analysis revealed 61 upregulated and 57 downregulated proteins by C2A-2B-3-4 with very limited overlap with those affected by L2A-2B-3-4. Independent validations confirmed the effect of C2A-2B-3-4 on expression of genes associated with chromatin remodeling, transcription, spliceosome function, ribosome biogenesis, lipid metabolism, cytoskeletal formation, cell proliferation and neuromuscular junction formation. Our findings reveal a broad role of C2A-2B-3-4, and expands our understanding of functions of SMN1/2 genes.
摘要：
脊髓性肌萎缩症（SMA）基因，SMN1和SMN2（以下简称SMN1/2），产生多个环状RNA(circRNAs)，包括包含早期外显子2A的C2A-2B-3-4，2B,3和4。C2A-2B-3-4是SMN1/2的普遍且大量表达的circRNA。在这里，我们报道了C2A-2B-3-4在诱导型HEK293细胞中过表达的转录组和蛋白质组范围的影响。我们的RNA-Seq分析显示C2A-2B-3-4改变了约15%基因(4172个基因)的表达。受C2A-2B-3-4影响的基因中约有一半不受L2A-2B-3-4影响，L2A-2B-3-4是包含外显子2A的线性转录本，2B,3和SMN1/2的4。这些发现强调了C2A-2B-3-4的结构背景在基因调控中的独特作用。令人惊讶的是，C2A-2B-3-4上调的基因位于4号和7号染色体上，而许多下调的基因位于10号和X号染色体上。支持SMN1/2转录本的交叉调节，C2A-2B-3-4和L2A-2B-3-4上调和下调SMN1/2mRNA，分别。蛋白质组分析显示，C2A-2B-3-4有61种上调和57种下调的蛋白质，与受L2A-2B-3-4影响的蛋白质重叠非常有限。独立验证证实了C2A-2B-3-4对染色质重塑相关基因表达的影响，转录,剪接体函数，核糖体生物发生，脂质代谢，细胞骨架形成，细胞增殖和神经肌肉接头形成。我们的发现揭示了C2A-2B-3-4的广泛作用，并扩展了我们对SMN1/2基因功能的理解。
