Expression levels and spatial distribution of AtCOX17 are regulated by a complex mechanism including cis-regulatory motifs and chromatin regulatory factors

TORTI PABLO; FEDERICO, ARIEL; ATTHALA, CAROLINA; GONZALEZ, DANIEL H.; WELCHEN, ELINA

Buenos Aires

Congreso; LASDB Xth; 2019

We have previously characterized promoter regions of several accessory proteins involved in mitochondrial biogenesis in Arabidopsis. A relative common characteristic of these genes is the presence of an intron in their 5? UTR. We characterize the regulatory mechanisms for the expression of the Arabidopsis gene COX17, encoding for a metallochaperone that transport copper into the COX in the mitochondrial respiratory chain. This gene is induced by abiotic stress like UV-B or salinity. We identify that the presence of this intron in their 5? UTR is necessary for gene expression. Into this region we identify three telo-box motifs in tandem and we focus on their function. We analysed the expression of the reporter GUS directed by the wt intron and one mutated intron in wich the telo-boxs motif were deleted or mutated in tandem or individually. The expression and the activity of the reporter gene increased in the mutated versions. It?s been described that telo-box motif can recruit the polycom repressor complex 2 (PRC2) and downregulates gene expression by methylation of DNA. We found H3K27m3 marks in the region in these elements and increased levels of COX17 in mutants of PRC2. Based on this, we can postulate that COX17 expression is regulated by telo-box motif wichs recruit the PRC2. We assume that the expression of COX17 or its RNA stability is also related to an internal element, an antisense-lncRNA, for whose function is not yet clear.