Transcriptional coordination of genes encoding plant mitochondrial respiratory chain components

DANIEL H. GONZÁLEZ, CAROLINA V. ATTALLAH, RAÚL N. COMELLI, EDUARDO F. MUFARREGE, ELINA WELCHEN

Rosario, Argentina

Simposio; XLII Reunión Anual de la Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB); 2006

Sociedad Argentina de Investigación Bioquímica y Biología Molecular (SAIB)

Biogenesis of the mitochondrial respiratory chain requires the expression of a vast set of genes from two different genomes. It is generally assumed that the expression of most genes that encode respiratory components must be somehow coordinated. We are studying the expression of Arabidopsis genes encoding proteins involved in respiration to determine the extent, conditions and mechanisms of this coordination in plants. Analysis of expression data from available microarray experiments indicates that most nuclear genes encoding respiratory chain components show similar expression characteristics and responses. Studies on the promoter of one of the Arabidopsis cytochrome c genes using deletions and mutagenesis indicated that DNA elements known as site II, that bind transcription factors of the TCP family, are essential for expression. Similar motifs are present in most promoters of nuclear genes encoding respiratory components. Mutagenesis of site II elements in several of these promoters revealed their importance for expression. Cluster analysis of microarray experiments allowed the identification of other genes that show similar expression characteristics. Genes encoding mitochondrial components and promoters with site II elements are enriched in this group of genes, reinforcing the notion of coordination of gene expression through these elements during mitochondrial biogenesis.