Characterization of Arabidopsis genes encoding cytochrome c oxidase assembly factors

CAROLINA V. ATTALLAH, ELINA WELCHEN, RAÚL N. COMELLI Y DANIEL H. GONZÁLEZ.

Villa Carlos Paz, Córdoba. Argentina.

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

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

The biogenesis of cytochrome c oxidase (COX) requires accesory proteins, including COX11, COX17, and SCO1, that have been implicated in copper metallation of two COX subunits. Another protein, COX19, is essential for COX biogenesis but its exact function is unknown. Based on structural similarities with COX17, it has also been implicated in metal transport. The Arabidopsis genome contains one AtCOX11 gene and  two genes for each AtCOX17, AtCOX19, and AtSCO1. It is noteworthy that AtCOX11, AtCOX17 and AtCOX19 genes contain an intron located near the translation start site and share certain motifs in their promoter proximal regions. Expression of AtCOX17 and AtCOX19 genes was localized preferentially in young roots, anthers and siliques and was induced by different treatments that produce oxidative stress in plants. Expression of these genes was completely dependent on the presence of the intron and site II motifs located around -200 from the translation start site. For AtCOX11, similar expression patterns were observed, but induction by stress and dependence on the intron and site II motifs was not evident. Our results indicate that, in addition to the structural similarities observed for COX17 and COX19 proteins, the expression mechanisms of these genes are highly conserved. This further supports the view that these copper chaperones have closely related functions in COX assembly.