IAL   21557
INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
An Open Reading Frame present in the 5?UTR of the Arabidopsis AtHB1 gene repressed its translation
Autor/es:
CAPELLA M; RIBONE PA; CHAN RL
Lugar:
Córdoba
Reunión:
Congreso; LII Reunión de Sociedad Argentina de Investigación Bioquímica y Biología Molecular; 2016
Institución organizadora:
Sociedad Argentina de Investigación Bioquímica y Biología Molecular
Resumen:
AtHB1 is an Arabidopsis transcription factor (TF) belonging to the HD-Zip I subfamily. It was previously demonstrated that this TF interacts with AtTBP2 to exert its function, acting downstream of PIF1. The AtHB1 gene is expressed in hypocotyls and roots to regulate genes involved in the elongation and synthesis of the cell wall.Here we show that bioinformatic analyses considering AtHB1 homologues in several plant species resulted in the detection of a conserved upstream Open Reading Frame (uORF) in the 5?UTR region of these genes, named CPuORF33. These uORFs exhibit a higher degree of conservation in the aminoacidic sequences than in the nucleotide ones, and they do not overlap with the mORF (main ORF). Generation of different constructs, bearing the native or/and the mutated uORF, used to transform Arabidopsis plants allowed us to demonstrate that the CPuORF33 represses the mORF translation but not transcription, independently on the mORF nature. This regulation occurs in cis, probably through a ribosome stalling mechanism. On the other hand, AtHB1 overexpression is also repressed by small RNAs in Arabidopsis.Altogether, our results reveal a novel mechanism by which the expression of AtHB1 (and that of its homologues in other plant species) is tightly regulated in order to avoid aberrant phenotypes observed when the TF is overexpressed leading to sterile plants.