An antagonistic function for Arabidopsis DCL2 in development and a new function for DCL4 in generating viral siRNAs
An antagonistic function for Arabidopsis DCL2 in development and a new function for DCL4 in generating viral siRNAs
复制标题
DOI：
10.1038/sj.emboj.7601217
复制
发表时间：
2006-07-26
期刊：
影响因子：
11.4
通讯作者：
Vaucheret, Herve
中科院分区：
文献类型：
--
作者：
Bouche, Nicolas;Lauressergues, Dominique;Vaucheret, Herve
植物比其他真核生物含有更多的DICER-LIKE（DCL）酶和双链RNA结合（DRB）蛋白，导致小RNA网络复杂性增加。对单、双、三和四重dcl突变体的分析表明，DCL 1是一种复杂的酶，能够产生microRNA（miRNA）和siRNA，不像其他三种DCL只产生siRNA。siRNA特异性DCL的耗尽导致不平衡的小RNA水平，表明DCL/DRB复合物的重新部署。特别地，DCL 2在某些情况下拮抗由DCL 1产生的miRNA和siRNA，并且不利地影响dcl 1 dcl 4和dcl 1 dcl 3 dcl 4突变体植物的发育，而dcl 1 dcl 2 dcl 3 dcl 4四重突变体植物是存活的。我们还表明，病毒siRNA是由DCL 4产生的，当后者的活性被病毒降低或抑制时，DCL 2可以取代DCL 4，这表明DCL 2具有竞争力。考虑到植物中小RNA库的复杂性，每个DCL，特别是DCL 2，在产生没有已知功能的小RNA中的意义将构成下一个挑战之一。
Plants contain more DICER-LIKE (DCL) enzymes and double-stranded RNA binding (DRB) proteins than other eukaryotes, resulting in increased small RNA network complexities. Analyses of single, double, triple and quadruple dcl mutants exposed DCL1 as a sophisticated enzyme capable of producing both microRNAs ( miRNAs) and siRNAs, unlike the three other DCLs, which only produce siRNAs. Depletion of siRNA-specific DCLs results in unbalanced small RNA levels, indicating a redeployment of DCL/DRB complexes. In particular, DCL2 antagonizes the production of miRNAs and siRNAs by DCL1 in certain circumstances and affects development deleteriously in dcl1 dcl4 and dcl1 dcl3 dcl4 mutant plants, whereas dcl1 dcl2 dcl3 dcl4 quadruple mutant plants are viable. We also show that viral siRNAs are produced by DCL4, and that DCL2 can substitute for DCL4 when this latter activity is reduced or inhibited by viruses, pointing to the competitiveness of DCL2. Given the complexity of the small RNA repertoire in plants, the implication of each DCL, in particular DCL2, in the production of small RNAs that have no known function will constitute one of the next challenges.