EXPRESSION ANALYSIS OF COX19 GENES IN ARABIDOPSIS

ATTALLAH CV, WELCHEN E, GONZÁLEZ DH.

Iguazú, Misiones. Argentina.

Congreso; XL Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2004

SOCIEDAD ARGENTINA DE INVESTIGACIÓN BIOQUÍMICA Y BIOLOGÍA MOLECULAR

We have studied the expression of an Arabidopsis novel nuclear gene, Atcox19, that shares sequence similarity to cox19, a gene encoding a protein required for expression of cytochrome oxidase in Saccharomyces cerevisiae. COX19p  is present in the cytoplasm and mitochondria of yeast. This protein probably functions post-translationally during assembly of the enzyme and it is likely to be involved in metal transport. In Arabidopsis, there are two genes for cox19 with high sequence homology and two cDNAs that are originated in an alternative splicing event from one of these two genes. To study the expression mechanisms of this gene we have made northern blot analysis. Incubation of plants in solutions containing metal ions (Cu2+, Fe2+, Zn2+), compounds related with the generation of reactive oxygen species, like salicylic acid, sodium nitroprusside and H2O2, cytokinins (6-benzylaminopurine) and carbohydrates (sucrose), produced an increase in transcript levels. Our results, as well as the presence of four conserved cysteine residues in AtCOX19p, suggest that the products of Atcox19 may function in metal transport to mitochondria and cytochrome c oxidase assembly in plants.