PDF(Pubmed)
Abstract：
Although lack of ADAR (adenosine deaminase acting on RNA) orthologs, genome-wide A-to-I editing occurs specifically during sexual reproduction in a number of filamentous ascomycetes, including Fusarium graminearum and Neurospora crassa. Unlike ADAR-mediated editing in animals, fungal A-to-I editing has a strong preference for hairpin loops and U at -1 position, which leads to frequent editing of UAG and UAA stop codons. Majority of RNA editing events in fungi are in the coding region and cause amino acid changes. Some of these editing events have been experimentally characterized for providing heterozygote and adaptive advantages in F. graminearum. Recent studies showed that FgTad2 and FgTad3, 2 ADAT (adenosine deaminase acting on tRNA) enzymes that normally catalyze the editing of A34 in the anticodon of tRNA during vegetative growth mediate A-to-I mRNA editing during sexual reproduction. Stage specificity of RNA editing is conferred by stage-specific expression of short transcript isoforms of FgTAD2 and FgTAD3 as well as cofactors such as AME1 and FIP5 that facilitate the editing of mRNA in perithecia. Taken together, fungal A-to-I RNA editing during sexual reproduction is catalyzed by ADATs and it has the same sequence and structural preferences with editing of A34 in tRNA.
摘要：
虽然缺乏ADAR（腺苷脱氨酶作用于RNA）直向同源物，全基因组A到I编辑特别发生在有性生殖过程中，在许多丝状子囊菌中，包括镰刀菌和粗糙神经孢子菌。与动物中ADAR介导的编辑不同，真菌A-to-I编辑对发夹环和U在-1位置有很强的偏好，这导致UAG和UAA终止密码子的频繁编辑。真菌中的大多数RNA编辑事件都在编码区并引起氨基酸变化。这些编辑事件中的一些已经在实验上表征为在禾谷镰刀菌中提供杂合子和适应性优势。最近的研究表明，在营养生长过程中通常催化tRNA反密码子中A34编辑的FgTad2和FgTad3，2ADAT（作用于tRNA的腺苷脱氨酶）酶介导有性生殖过程中的A到ImRNA编辑。RNA编辑的阶段特异性是由FgTAD2和FgTAD3的短转录同种型以及辅因子如AME1和FIP5的阶段特异性表达赋予的，这些因子有助于在鞘周中编辑mRNA。一起来看,有性生殖过程中的真菌A到IRNA编辑由ADAT催化，并且与tRNA中A34的编辑具有相同的序列和结构偏好。
