IAL   21557
INSTITUTO DE AGROBIOTECNOLOGIA DEL LITORAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
The expression of the Arabidopsis COX17 gene is regulated by an intron into their 5?URT and the polycomb repressor complex 2.
Autor/es:
TORTI P; WELCHEN E; ARIEL F; ATTALLAH C
Reunión:
Congreso; LASDB Meeting 2019 Xth Meeting of the Latin American Society for Developmental Biology; 2019
Resumen:
A common characteristic of genes encoding accessory proteins for Cytochrome c Oxidase (COX) biogenesis in Arabidopsis, is the presence of an intron-leader in the 5'-UTR region with regulatory functions on their expression. We characterised the expression of AtCOX17, coding for a metallochaperone involved in the copper delivery into COX. AtCOX17 is induced by abiotic stress like UV-B or salinity, both at the transcriptional and post-transcriptional levels. AtCOX17 possesses a 5?-UTR intron, that is necessary for detectable gene expression in all tissues were it was analysed. Into this region, we identified a segment containing three cis-regulatory motifs known as telo-box, positioned in tandem. We analysed the expression of the GUS reporter gene, driven by AtCOX17 promoter, including a WT or a mutated version of the telo-box motifs presents in their intron leader. GUS-reporter expression and their activity were highly increased when telo-box were mutated. Also, the tissue expression patterns of AtCOX17, analysed by histochemical staining, were considerably changed. Recently, it was proposed that telo-box motif recruits proteins of the Polycomb Repressor Complex 2 (PRC2) that downregulate gene expression by DNA methylation. By performing a CHIP-qPCR assay, we found an enrichment in the H3K27m3 marks in the intron region of AtCOX17. In agreement, levels of AtCOX17 were higher in prc2-mutant backgrounds. We postulate that the spatial tissue-distribution and the expression levels of AtCOX17 are regulated by a complex mechanism that includes telo-box motifs presents in the intronic region, wichs probably recruit proteins of the PRC2, to fine-tune the expression of this metallochaperone basally or under different stress conditions.