title: Bruno-like proteins modulate flowering time via 3' UTR-dependent decay of SOC1 mRNA.
abstract: The Bruno RNA-binding protein (RBP) has been shown to initially repress the translation of oskar mRNA during Drosophila oogenesis and later to be involved in a broad range of RNA regulation. Here, we show that homologous constitutive overexpression of each of two Arabidopsis thaliana Bruno-like genes, AtBRN1 and AtBRN2, delayed the flowering time, while the atbrn1 atbrn2-3 double mutant flowered early and exhibited increased expression of APETALA1 (AP1) and LEAFY (LFY) transcripts. Crossing of 35S::AtBRNs with SOC1 101-D plants demonstrated that 35S::AtBRNs suppress an early-flowering phenotype of SOC1 101-D in which the coding sequence (CDS) with the 3' UTR of SUPPRESSOR OF OVEREXPRESSION OF CONSTANS1 (SOC1) gene is overexpressed. However, this early-flowering phenotype by SOC1 overexpression was maintained in the plants coexpressing 35S::AtBRNs and 35S::SOC1 without the 3' UTR (-3' UTR). Using yeast three-hybrid, electrophoretic mobility shift, RNA immunoprecipitation, and protoplast transient assays, we found that AtBRNs bind to the 3' UTR of SOC1 RNA and participate in mRNA decay, which was mediated by the distal region of the SOC1 3' UTR. Overall, AtBRNs repress SOC1 activity in a 3' UTR-dependent manner, thereby controlling the flowering time in Arabidopsis.
authors: Division of Bioscience and Bioinformatics, Myongji University, Yongin, Kyunggi-do, 449-728, South Korea.
authors: Hyung-Sae
authors: HS
authors: Kim
authors: School of Biotechnology and Environmental Engineering, Myongji University, Yongin, Kyunggi-do, 449-728, South Korea.
authors: Nazia
authors: N
authors: Abbasi
authors: Division of Bioscience and Bioinformatics, Myongji University, Yongin, Kyunggi-do, 449-728, South Korea.|School of Biotechnology and Environmental Engineering, Myongji University, Yongin, Kyunggi-do, 449-728, South Korea.
authors: Sang-Bong
authors: SB
authors: Choi
mesh_terms: D020413:3' Untranslated Regions; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics; D004843:Epistasis, Genetic; D035264:Flowers / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D026161:MADS Domain Proteins / Q000235:genetics* / Q000378:metabolism*; D010641:Phenotype; D030821:Plants, Genetically Modified; D020871:RNA Stability / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors
chemical_list: D020413:3' Untranslated Regions; C419046:AGL20 protein, Arabidopsis; D029681:Arabidopsis Proteins; D029721:Drosophila Proteins; D026161:MADS Domain Proteins; C584520:MADS-box protein SOC1, Arabidopsis; D016601:RNA-Binding Proteins; C584519:RNA-binding protein-defense related 1, Arabidopsis; C093437:bru1 protein, Drosophila