SINE RNA induces severe developmental defects in Arabidopsis thaliana and interacts with HYL1 (DRB1), a key member of the DCL1 complex.
The proper temporal and spatial expression of genes during plant development is governed, in part, by the regulatory activities of various types of small RNAs produced by the different RNAi pathways. Here we report that transgenic Arabidopsis plants constitutively expressing the rapeseed SB1 SINE retroposon exhibit developmental defects resembling those observed in some RNAi mutants. We show that SB1 RNA interacts with HYL1 (DRB1), a double-stranded RNA-binding protein (dsRBP) that associates with the Dicer homologue DCL1 to produce microRNAs. RNase V1 protection assays mapped the binding site of HYL1 to a SB1 region that mimics the hairpin structure of microRNA precursors. We also show that HYL1, upon binding to RNA substrates, induces conformational changes that force single-stranded RNA regions to adopt a structured helix-like conformation. Xenopus laevis ADAR1, but not Arabidopsis DRB4, binds SB1 RNA in the same region as HYL1, suggesting that SINE RNAs bind only a subset of dsRBPs. Consistently, DCL4-DRB4-dependent miRNA accumulation was unchanged in SB1 transgenic Arabidopsis, whereas DCL1-HYL1-dependent miRNA and DCL1-HYL1-DCL4-DRB4-dependent tasiRNA accumulation was decreased. We propose that SINE RNA can modulate the activity of the RNAi pathways in plants and possibly in other eukaryotes.
Pouch-Pélissier
Marie-Noëlle
MN
Université de Perpignan Via Domitia, CNRS UMR5096 LGDP, Perpignan, France.
Pélissier
Thierry
T
Elmayan
Taline
T
Vaucheret
Hervé
H
Boko
Drasko
D
Jantsch
Michael F
MF
Deragon
Jean-Marc
JM
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D009690:Nucleic Acid Conformation; D018749:RNA, Plant / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D043244:Ribonuclease III / Q000235:genetics / Q000378:metabolism*; D020086:Short Interspersed Nucleotide Elements
D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; C511456:DRB4 protein, Arabidopsis; C420966:HYL1 protein, Arabidopsis; D035683:MicroRNAs; D018832:Molecular Chaperones; D018749:RNA, Plant; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C402383:DCL1 protein, Arabidopsis; D043244:Ribonuclease III