title: Arabidopsis ARGONAUTE7 selects miR390 through multiple checkpoints during RISC assembly.
abstract: Plant ARGONAUTE7 (AGO7) assembles RNA-induced silencing complex (RISC) specifically with miR390 and regulates the auxin-signalling pathway via production of TAS3 trans-acting siRNAs (tasiRNAs). However, how AGO7 discerns miR390 among other miRNAs remains unclear. Here, we show that the 5' adenosine of miR390 and the central region of miR390/miR390* duplex are critical for the specific interaction with AGO7. Furthermore, despite the existence of mismatches in the seed and central regions of the duplex, cleavage of the miR390* strand is required for maturation of AGO7-RISC. These findings suggest that AGO7 uses multiple checkpoints to select miR390, thereby circumventing promiscuous tasiRNA production.
authors.affiliation: Institute of Molecular and Cellular Biosciences, Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 1-1-1, Yayoi, Bunkyo-ku, Tokyo 113-0032, Japan.
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Endo
authors.forename: Hiro-oki
authors.initials: HO
authors.lastname: Iwakawa
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Tomari
mesh_terms: D000241:Adenosine / Q000737:chemistry / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D059367:RNA Cleavage; D018749:RNA, Plant / Q000235:genetics* / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics* / Q000378:metabolism; D034743:RNA-Induced Silencing Complex / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; C584086:MIRN390 microRNA, Arabidopsis; D035683:MicroRNAs; D018749:RNA, Plant; D034741:RNA, Small Interfering; D034743:RNA-Induced Silencing Complex; C486145:ZIPPY protein, Arabidopsis; D000241:Adenosine