Intron retention and transcript chimerism conserved across mammals: Ly6g5b and Csnk2b-Ly6g5b as examples
Intron retention and transcript chimerism conserved across mammals: Ly6g5b and Csnk2b-Ly6g5b as examples
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DOI：
10.1186/1471-2164-14-199
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发表时间：
2013-03-22
期刊：
影响因子：
4.4
通讯作者：
Aguado, Begona
中科院分区：
文献类型：
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作者：
Hernandez-Torres, Francisco;Rastrojo, Alberto;Aguado, Begona
背景：选择性剪接（AS）是调节生物体基因表达的主要机制，允许从一个独特的基因合成几种结构和功能不同的mrna和蛋白质亚型。与AS相关的是转录诱导嵌合（TIC）或串联嵌合（Tandem Chimerism），通过这种嵌合可以发现相邻基因之间的嵌合rna，增加蛋白质组的组合复杂性。Ly6g5b基因在其表达中表现出特殊的行为，包括内含子保留事件，并能够与上游基因Csnk2b形成RNA嵌合体转录本。我们想在六种不同哺乳动物的四种组织中更深入地描述这些事件，并分析它们的蛋白质产物。结果：虽然典型的Csnk2b亚型广泛表达，但Ly6g5b亚型不太普遍，尽管Ly6g5b第一内含子保留转录物存在于所有分析的组织和物种中。Csnk2b-Ly6g5b嵌合体存在于所有分析的样品中，但具有受限的表达模式。其中一些嵌合转录本保持了来自Csnk2b和Ly6g5b的正确结构域。此外，我们发现Csnk2b、Ly6g5b和Csnk2b-Ly6g5b转录本存在外显子跳跃、5‘和3’剪切位点替代和内含子保留事件。这将产生截断或异常的蛋白质，其作用仍然未知。一些嵌合转录物编码CSNK2B蛋白，其c端发生改变，从而影响其生物学功能，扩大其底物特异性。人CSNK2B、LY6G5B和CSNK2B-LY6G5B蛋白的过表达表现出不同的翻译后修饰和细胞分布模式。结论：Ly6g5b内含子保留和Csnk2b-Ly6g5b转录嵌合现象广泛分布于不同哺乳动物的组织中。
Background: Alternative splicing (AS) is a major mechanism for modulating gene expression of an organism, allowing the synthesis of several structurally and functionally distinct mRNAs and protein isoforms from a unique gene. Related to AS is the Transcription Induced Chimerism (TIC) or Tandem Chimerism, by which chimeric RNAs between adjacent genes can be found, increasing combinatorial complexity of the proteome. The Ly6g5b gene presents particular behaviours in its expression, involving an intron retention event and being capable to form RNA chimera transcripts with the upstream gene Csnk2b. We wanted to characterise these events more deeply in four tissues in six different mammals and analyse their protein products.Results: While canonical Csnk2b isoform was widely expressed, Ly6g5b canonical isoform was less ubiquitous, although the Ly6g5b first intron retained transcript was present in all the tissues and species analysed. Csnk2b-Ly6g5b chimeras were present in all the samples analysed, but with restricted expression patterns. Some of these chimeric transcripts maintained correct structural domains from Csnk2b and Ly6g5b. Moreover, we found Csnk2b, Ly6g5b, and Csnk2b-Ly6g5b transcripts that present exon skipping, alternative 5' and 3' splice site and intron retention events. These would generate truncated or aberrant proteins whose role remains unknown. Some chimeric transcripts would encode CSNK2B proteins with an altered C-terminus, which could affect its biological function broadening its substrate specificity. Over-expression of human CSNK2B, LY6G5B, and CSNK2B-LY6G5B proteins, show different patterns of post-translational modifications and cell distribution.Conclusions: Ly6g5b intron retention and Csnk2b-Ly6g5b transcript chimerism are broadly distributed in tissues of different mammals.