MEC-8 regulates alternative splicing of unc-52 transcripts in C. elegans hypodermal cells.
MEC-8 regulates alternative splicing of unc-52 transcripts in C. elegans hypodermal cells.
复制标题
DOI：
--
复制
发表时间：
2002-11
期刊：
影响因子：
4.6
通讯作者：
C. Spike;A. Davies;J. Shaw;R. K. Herman
中科院分区：
文献类型：
--
作者：
C. Spike;A. Davies;J. Shaw;R. K. Herman
先前的研究表明，秀丽隐杆线虫的MEC-8是一种假定的rna结合蛋白，可促进unc-52转录物的特异性选择性剪接。Unc-52编码哺乳动物的perlecan同源物，它位于细胞外的肌肉和皮下组织之间，对胚胎和幼虫的肌肉发育至关重要。我们发现MEC-8是在大多数发育阶段的皮下发现的核蛋白，而不是在大多数晚期胚胎或幼虫的体壁肌肉中发现。我们还发现MEC-8在皮下而非肌肉中过表达可以抑制某些unc-52突变表型。这是出乎意料的结果，因为有人认为UNC-52只由肌肉产生。我们已经构建了各种组织特异性的unc-52小基因融合到绿色荧光蛋白的基因，使我们能够监测组织特异性的mec-8依赖性的选择性剪接；我们发现，为了调节unc-52的表达，mec-8必须在与unc-52基因相同的细胞类型中表达，这支持了mec-8直接作用于unc-52转录本，而unc-52必须主要由皮下组织合成的观点。事实上，我们对unc-52基因嵌合体的分析表明，unc-52的作用重点不在体壁肌肉，而很可能在皮下组织。
Previous work has shown that C. elegans MEC-8 is a putative RNA-binding protein that promotes specific alternative splices of unc-52 transcripts. unc-52 encodes homologs of mammalian perlecan that are located extracellularly between muscle and hypodermis and are essential for muscle development in both embryos and larvae. We show that MEC-8 is a nuclear protein found in hypodermis at most stages of development and not in most late embryonic or larval body-wall muscle. We have also found that overexpression of MEC-8 in hypodermis but not muscle can suppress certain unc-52 mutant phenotypes. These are unexpected results because it has been proposed that UNC-52 is produced exclusively by muscle. We have constructed various tissue-specific unc-52 minigenes fused to a gene for green fluorescent protein that have allowed us to monitor tissue-specific mec-8-dependent alternative splicing; we show that mec-8 must be expressed in the same cell type as the unc-52 minigene in order to regulate its expression, supporting the view that MEC-8 acts directly on unc-52 transcripts and that UNC-52 must be synthesized primarily by the hypodermis. Indeed, our analysis of unc-52 genetic mosaics has shown that the focus of unc-52 action is not in body-wall muscle but most likely is in hypodermis.