CARPEL FACTORY, a Dicer homolog, and HEN1, a novel protein, act in microRNA metabolism in Arabidopsis thaliana
CARPEL FACTORY, a Dicer homolog, and HEN1, a novel protein, act in microRNA metabolism in Arabidopsis thaliana
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DOI：
10.1016/s0960-9822(02)01017-5
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发表时间：
2002-09-03
期刊：
影响因子：
9.2
通讯作者：
Chen, XM
中科院分区：
文献类型：
--
作者：
Park, W;Li, JJ;Chen, XM
背景：在后生动物中，microRNA或miRNAs构成了一个不断增长的小调控RNA家族，通常长度为19-25个核苷酸。它们由较长的前体RNA加工而成，这些前体RNA通过核糖核酸酶Dicer折叠成茎环结构，并被认为通过与蛋白质编码基因的RNA进行碱基配对来调节基因表达。在拟南芥（Arabidopsis thaliana）中，一个Dicer同源基因CARPEL FACTORY（CAF）的突变和一个新基因HEN 1的突变导致了相似的多方面的发育缺陷，这表明这两个基因的功能相似，可能在miRNA代谢中。为了研究CAF和HEN 1在miRNA代谢中的潜在功能，我们的目的是从拟南芥中分离miRNAs，并在野生型植物和hen 1 -1和caf-1突变体植物中检测它们在植物发育过程中的积累。我们已经分离出11种miRNAs，其中一些在烟草、水稻和玉米中具有潜在的同源物。这些miRNA的推定前体具有形成稳定茎环结构的能力。这些miRNAs的积累似乎在植物发育中受到空间或时间控制，并且它们的丰度在caf-1和hen 1 -1突变体中大大降低。在细菌、真菌和后生动物的基因组中发现了HEN 1同源物。结论：miRNAs在植物和动物界都存在。一种涉及蛋白质的进化保守机制在miRNA代谢中发挥作用，该蛋白质在动物中称为Dicer，在拟南芥中称为CAF。HEN 1是拟南芥中miRNA积累的新参与者，后生动物中的HEN 1同源物可能具有类似的功能。与caf-1和hen 1 -1突变相关的发育缺陷以及miRNA积累的模式表明，miRNA在植物发育中起着重要作用。
Background: In metazoans, microRNAs, or miRNAs, constitute a growing family of small regulatory RNAs that are usually 19-25 nucleotides in length. They are processed from longer precursor RNAs that fold into stem-loop structures by the ribonuclease Dicer and are thought to regulate gene expression by base pairing with RNAs of protein-coding genes. In Arabidopsis thaliana, mutations in CARPEL FACTORY (CAF), a Dicer homolog, and those in a novel gene, HEN1, result in similar, multifaceted developmental defects, suggesting a similar function of the two genes, possibly in miRNA metabolism.Results: To investigate the potential functions of CAF and HEN1 in miRNA metabolism, we aimed to isolate miRNAs from Arabidopsis and examine their accumulation during plant development in wild-type plants and in hen1-1 and caf-1 mutant plants. We have isolated 11 miRNAs, some of which have potential homologs in tobacco, rice, and maize. The putative precursors of these miRNAs; have the capacity to form stable stem-loop structures. The accumulation of these miRNAs; appears to be spatially or temporally controlled in plant development, and their abundance is greatly reduced in caf-1 and hen1-1 mutants. HEN1 homologs are found in bacterial, fungal, and metazoan genomes.Conclusions: miRNAs are present in both plant and animal kingdoms. An evolutionarily conserved mechanism involving a protein, known as Dicer in animals and CAF in Arabidopsis, operates in miRNA metabolism. HEN1 is a new player in miRNA accumulation in Arabidopsis, and HEN1 homologs in metazoans may have a similar function. The developmental defects associated with caf-1 and hen1-1 mutations and the patterns of miRNA accumulation suggest that miRNAs play fundamental roles in plant development.