title: Introns of plant pri-miRNAs enhance miRNA biogenesis.
abstract: Plant MIR genes are independent transcription units that encode long primary miRNA precursors, which usually contain introns. For two miRNA genes, MIR163 and MIR161, we show that introns are crucial for the accumulation of proper levels of mature miRNA. Removal of the intron in both cases led to a drop-off in the level of mature miRNAs. We demonstrate that the stimulating effects of the intron mostly reside in the 5'ss rather than on a genuine splicing event. Our findings are biologically significant as the presence of functional splice sites in the MIR163 gene appears mandatory for pathogen-triggered accumulation of miR163 and proper regulation of at least one of its targets.
authors.affiliation: Department of Gene Expression, Faculty of Biology, Adam Mickiewicz University, Umultowska Street 89, 61-614 Poznan, Poland.
authors.forename: Dawid
authors.initials: D
authors.lastname: Bielewicz
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Kalak
authors.forename: Maria
authors.initials: M
authors.lastname: Kalyna
authors.forename: David
authors.initials: D
authors.lastname: Windels
authors.forename: Andrea
authors.initials: A
authors.lastname: Barta
authors.forename: Franck
authors.initials: F
authors.lastname: Vazquez
authors.forename: Zofia
authors.initials: Z
authors.lastname: Szweykowska-Kulinska
authors.forename: Artur
authors.initials: A
authors.lastname: Jarmolowski
mesh_terms: D017398:Alternative Splicing; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000382:microbiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D007438:Introns; D008780:Methyltransferases / Q000235:genetics / Q000378:metabolism; D035683:MicroRNAs / Q000096:biosynthesis / Q000235:genetics*; D009154:Mutation; D011061:Poly A / Q000235:genetics / Q000378:metabolism; D044224:Pseudomonas syringae / Q000502:physiology; D012322:RNA Precursors / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; C577258:MIRN163 microRNA, Arabidopsis; D035683:MicroRNAs; D012322:RNA Precursors; D011061:Poly A; D008780:Methyltransferases; C434266:S-adenosyl-L-methionine-dependent N-methyltransferase