Introns and splicing elements of five diverse fungi
Introns and splicing elements of five diverse fungi
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DOI：
10.1128/ec.3.5.1088-1100.2004
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发表时间：
2004-10-01
期刊：
影响因子：
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通讯作者：
Murphy, JW
中科院分区：
文献类型：
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作者：
Kupfer, DM;Drabenstot, SD;Murphy, JW
不同真菌（酿酒酵母、粟酒裂殖酵母、构巢曲霉、粗糙脉孢菌和新型隐球菌）的基因组序列和表达序列标签数据提供了准确表征保守内含子元件的机会。对大型内含子数据集的检查显示，真菌内含子一般都很短，其中98%或更多属于典型剪接位点（ss）类（5 'GU... AG 3 '），并且它们具有多聚嘧啶束，主要在5' ss和分支点之间的区域。在所检测的真菌中，内含子的5' ss、分支位点和3' ss区域中的信息含量高，而与内含子相邻的外显子区域中的信息含量低。与其他真菌相比，这两种酵母具有更宽的内含子长度范围和相应更高的内含子信息含量。通常，随着真菌中内含子长度的增加，内含子信息含量也增加。WAIT剪接体蛋白的同源物在除S.酿酒酵母，这表明在大多数内含子中没有典型的多聚嘧啶道的情况下U2 AF的非常规作用。我们的观察结果表明，真菌中的剪接可能不同于脊椎动物中的剪接，并且可能需要额外的蛋白质与多嘧啶道上游的分支点相互作用。发现了Nam 8 p和TIA-1的理论蛋白质同源物，这两种蛋白质需要分支点上游的富含U的区域来发挥功能。酿酒酵母和酿酒酵母。粟酒裂殖酵母内含子和子囊菌门的两个丝状成员和担子菌门的一个成员的内含子，以保证新的模式生物的发展，用于研究真菌的剪接机制。
Genomic sequences and expressed sequence tag data for a diverse group of fungi (Saccharomyces cerevisiae, Schizosaccharomyces pombe, Aspergillus nidulans, Neurospora crassa, and Cryptococcus neoformans) provided the opportunity to accurately characterize conserved intronic elements. An examination of large intron data sets revealed that fungal introns in general are short, that 98% or more of them belong to the canonical splice site (ss) class (5'GU...AG3'), and that they have polypyrimidine tracts predominantly in the region between the 5' ss and the branch point. Information content is high in the 5' ss, branch site, and 3' ss regions of the introns but low in the exon regions adjacent to the introns in the fungi examined. The two yeasts have broader intron length ranges and correspondingly higher intron information content than the other fungi. Generally, as intron length increases in the fungi, so does intron information content. Homologs of WAIT spliceosomal proteins were found in all species except for S. cerevisiae, suggesting a nonconventional role for U2AF in the absence of canonical polypyrimidine tracts in the majority of introns. Our observations imply that splicing in fungi may be different from that in vertebrates and may require additional proteins that interact with polypyrimidine tracts upstream of the branch point. Theoretical protein homologs for Nam8p and TIA-1, two proteins that require U-rich regions upstream of the branch point to function, were found. There appear to be sufficient differences between S. cerevisiae and S. pombe introns and the introns of two filamentous members of the Ascomycota and one member of the Basidiomycota to warrant the development of new model organisms for studying the splicing mechanisms of fungi.