Expression of the Drosophila melanogaster ATP synthase alpha subunit gene is regulated by a transcriptional element containing GAF and Adf-1 binding sites.

Mitochondrial biogenesis is a complex and highly regulated process that requires the controlled expression of hundreds of genes encoded in two separated genomes, namely the nuclear and mitochondrial genomes. To identify regulatory proteins involved in the transcriptional control of key nuclear-encoded mitochondrial genes, we have performed a detailed analysis of the promoter region of the alpha subunit of the Drosophila melanogaster F1F0 ATP synthase complex. Using transient transfection assays, we have identified a 56 bp cis-acting proximal regulatory region that contains binding sites for the GAGA factor and the alcohol dehydrogenase distal factor 1. In vitro mutagenesis revealed that both sites are functional, and phylogenetic footprinting showed that they are conserved in other Drosophila species and in Anopheles gambiae. The 56 bp region has regulatory enhancer properties and strongly activates heterologous promoters in an orientation-independent manner. In addition, Northern blot and RT-PCR analysis identified two alpha-F1-ATPase mRNAs that differ in the length of the 3' untranslated region due to the selection of alternative polyadenylation sites.