title: Regulation of a maize HD-ZIP IV transcription factor by a non-conventional RDR2-dependent small RNA.
abstract: Small non-coding RNAs are versatile riboregulators that control gene expression at the transcriptional or post-transcriptional level, governing many facets of plant development. Here we present evidence for the existence of a 24 nt small RNA (named small1) that is complementary to the 3' UTR of OCL1 (Outer Cell Layer1), the founding member of the maize HD-ZIP IV gene family encoding plant-specific transcription factors that are mainly involved in epidermis differentiation and specialization. The biogenesis of small1 depends on DICER-like 3 (DCL3), RNA-dependent RNA polymerase 2 (RDR2) and RNA polymerase IV, components that are usually required for RNA-dependent DNA-methylation. Unexpectedly, GFP sensor experiments in transient and stable transformation systems revealed that small1 may regulate its target at the post-transcriptional level, mainly through translational repression. This translational repression is attenuated in an rdr2 mutant background in which small1 does not accumulate. Our experiments further showed the possible involvement of a secondary stem-loop structure present in the 3' UTR of OCL1 for efficient target repression, suggesting the existence of several regulatory mechanisms affecting OCL1 mRNA stability and translation.
authors.affiliation: Unité Reproduction et Développement des Plantes, Université de Lyon, Ecole Normale Supérieure de Lyon, Université Lyon 1, F-69364, Lyon, France; Institut National de la Recherche Agronomique, UMR879 Reproduction et Développement des Plantes, F-69364, Lyon, France; Centre National de la Recherche Scientifique, UMR5667 Reproduction et Développement des Plantes, F-69364, Lyon, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Klein-Cosson
authors.forename: Pierre
authors.initials: P
authors.lastname: Chambrier
authors.forename: Peter M
authors.initials: PM
authors.lastname: Rogowsky
authors.forename: Vanessa
authors.initials: V
authors.lastname: Vernoud
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics; D019175:DNA Methylation; D018506:Gene Expression Regulation, Plant; D017930:Genes, Reporter; D008565:Membrane Proteins / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics*; D011499:Protein Processing, Post-Translational; D012333:RNA, Messenger / Q000235:genetics; D018749:RNA, Plant / Q000235:genetics; D034741:RNA, Small Interfering; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*; D003313:Zea mays / Q000235:genetics*
chemical_list: D020413:3' Untranslated Regions; D008565:Membrane Proteins; C120341:OCL1 protein, Zea mays; D010940:Plant Proteins; D012333:RNA, Messenger; D018749:RNA, Plant; D034741:RNA, Small Interfering; D014157:Transcription Factors; D012324:RNA-Dependent RNA Polymerase
keywords: DCL3; HD-ZIP IV; RDR2; hairpin; small RNA; translational repression