title: Degradation of microRNAs by a family of exoribonucleases in Arabidopsis.
abstract: microRNAs (miRNAs) play crucial roles in numerous developmental and metabolic processes in plants and animals. The steady-state levels of miRNAs need to be properly controlled to ensure normal development. Whereas the framework of miRNA biogenesis is established, factors involved in miRNA degradation remain unknown. Here, we show that a family of exoribonucleases encoded by the SMALL RNA DEGRADING NUCLEASE (SDN) genes degrades mature miRNAs in Arabidopsis. SDN1 acts specifically on single-stranded miRNAs in vitro and is sensitive to the 2'-O-methyl modification on the 3' terminal ribose of miRNAs. Simultaneous knockdown of three SDN genes in vivo results in elevated miRNA levels and pleiotropic developmental defects. Therefore, we have uncovered the enzymes that degrade miRNAs and demonstrated that miRNA turnover is crucial for plant development.
authors.affiliation: Department of Botany and Plant Sciences, Institute of Integrative Genome Biology, University of California Riverside, Riverside, CA 92521, USA.
authors.forename: Vanitharani
authors.initials: V
authors.lastname: Ramachandran
authors.forename: Xuemei
authors.initials: X
authors.lastname: Chen
mesh_terms: D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D060565:Argonaute Proteins; D005095:Exoribonucleases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017343:Genes, Plant; D026161:MADS Domain Proteins / Q000235:genetics; D008745:Methylation; D035683:MicroRNAs / Q000378:metabolism*; D018515:Plant Leaves / Q000254:growth & development / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: C117457:AGO1 protein, Arabidopsis; C091535:AP1 protein, Arabidopsis; D029681:Arabidopsis Proteins; D060565:Argonaute Proteins; D026161:MADS Domain Proteins; D035683:MicroRNAs; D018749:RNA, Plant; D034741:RNA, Small Interfering; D005095:Exoribonucleases; C531524:SDN1 protein, Arabidopsis
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