FUNCTIONAL STUDIES OF ARABIDOPSIS MAGO NASHI AND Y14 GENE PROMOTERS

MUFARREGE, EDUARDO; GONZÁLEZ, DANIEL AND CURI, GRACIELA

Carlos Paz

Congreso; XLIV Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2008

We have previously shown that expression of Arabidopsis COX5cCOX5c genes, encoding a cytochrome oxidase subunit, depends on a leader intron that produces an increase in transcription and translation efficiency. This effect may be mediated by the exon junction complex (EJC), a multiprotein assembly deposited by the spliceosome upstream of mRNA exon–exon junctions. The EJC is thought to provide a link between splicing and postsplicing mRNA metabolism, influencing mRNA export, stability, and translation. Two proteins of the EJC, Y14 and Mago, remain associated with the mRNA after its export to the cytoplasm. In this work, we tried to gain insight into the expression patterns of Arabidopsis Mago and Y14. For this, we analyzed GUS activity in plants that express the gus (ß-glucuronidase) gene under the control of AtY14 and AtMago promoter sequences. Both promoters direct GUS activity in the root meristem, cotyledon and leaf veins, and pollen grains. For Y14, expression was also observed in the root cortex, vascular bundle and hairs, in cotyledon blades, and the shoot apical meristem. The results indicate that both promoters produce partially overlapping expression patterns. Cells/tissues of preferential expression are coincident with those observed for the COX5c genes, suggesting that these proteins may be involved in the intron-mediated enhancement of the expression of these genes. the intron-mediated enhancement of the expression of these genes. genes, suggesting that these proteins may be involved in the intron-mediated enhancement of the expression of these genes.