Regulation of alternative splicing in the generation of isoforms of the mouse Ly-5 (CD45) glycoprotein.
Regulation of alternative splicing in the generation of isoforms of the mouse Ly-5 (CD45) glycoprotein.
复制标题
小鼠 Ly-5 (CD45) 糖蛋白亚型生成过程中选择性剪接的调节。
DOI：
10.1073/pnas.87.10.3728
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发表时间：
1990
影响因子：
11.1
通讯作者：
Boyse,EA
中科院分区：
文献类型：
--
作者：
Saga,Y;Lee,JS;Saraiya,C;Boyse,EA
选择性剪接产生细胞表面的各种Ly-5糖蛋白亚型，代表小鼠不同的细胞谱系和造血细胞分化阶段；外显子4-6被结合以产生B细胞亚型(B220)，并从T细胞亚型(T200)中排除，其他编码外显子(3和7-33)是共享的。作为了解Ly-5选择性剪接调控机制从而确定Ly-5亚型的第一步，我们将一个代表外显子3-7的微型基因导入表达Ly-5的T细胞和B细胞以及不表达Ly-5的L细胞，以比较剪接模式。我们的结论是，根据细胞类型选择忠实的剪接位点所需的所有信息都包含在生成的Pre-mRNA中。不表达的L细胞所表现出的剪接模式可能代表了一种缺省和非调节型。我们假设反式作用因子(S)可以解释合适的外显子的选择，我们通过对融合的杂交T-B细胞的分析提供了支持这一解释，这些细胞表现出B细胞特异性的Ly-5转录本。剪接模式被很好地保存下来，尽管结构发生了实质性的破坏。然而，广泛的缺失分析表明，外显子6两侧和内的顺式序列会影响T细胞中该外显子的排除。
Alternative splicing generates various Ly-5 glycoprotein isoforms of the cell surface that typify different cell lineages and stages of hematopoietic differentiation in the mouse; exons 4-6 are incorporated to generate a B-cell isoform (B220) and excluded from a T-cell isoform (T200), the other coding exons (3 and 7-33) being shared. As a first step to understanding the mechanisms regulating Ly-5 alternative splicing, and thus determining Ly-5 isoforms, a minigene representing exons 3-7 was transfected into Ly-5-expressor T cells and B cells and into nonexpressor L cells for comparison of splicing patterns. We conclude that all the information required for faithful splice-site selection according to cell type is contained within the resulting pre-mRNA. The splicing pattern manifested by nonexpressor L cells may represent a default and nonregulated type. We postulate trans-acting factor(s) to account for the selection of appropriate exons, and we provide support for this interpretation from analysis of fused hybrid T-B cells, which exhibited B-cell specific Ly-5 transcripts. Splicing patterns were well conserved despite substantial disruption of constructs. However, extensive deletion analyses suggested that cis sequences flanking and within exon 6 affect the exclusion of that exon in T cells.