Grant-funded Project Nr. 011/2004/C/1.LF
Final Report

Project title:Expression of genes coding for specific assembly factors of mammalian mitochondrial ATP synthase
Research leader:Ing. Andrea Pícková, 2000
Co-researcher: MUDr. Josef Houštěk, DrSc.; Mgr. Jan Paul; Kristýna Dudová
Period of project:2004-2004
Overall grant:154 000 CZK

Project Results

F1FO-ATP synthases are multisubunit enzyme complexes with common composition of the F1 sector while the structure of the FO part varies among organisms. Assembly of the yeast enzyme is not a self-catalysed process and rather requires at least five proteins with substrate-specific chaperone-type functions: Atp10p, Atp11p, Atp12p, Atp22p and Fmc1p.
We used primary data from genome sequenations to search for the yeast orthologues of ATP synthase assembly factors. We found that, similary to the subunit composition, the assembly of the F1 part is common to eukaryotic lineages capable of ATP synthesis via oxidative phosphorylation and dependends on the action of Atp11p and Atp12p. On the other hand, the assembly of the FO part goes in hand with the complexity of its structure and is more versatile. We report two subtypes of the FO-a subunit distinguishable by the requirement/nonessentiality of Atp10p chaperone. Furthemore, limited occurence of Atp22p and Fmc1p orthologues points to the existence of lineage-specific factors. Our phylogenetic data were further used for computational sequence analysis which identified evolutionary conserved residues, putative functional domains and their basic structural features for Atp10p, Atp11p and Atp12p orthologues. These results provide the basis for detailed molecular analysis of the ATP synthase-specific chaperones.
Hen serum, prepared against recombinant human Atpaf2p, reacted with the antigen only. A rabbit is currently undergoing immunization.
Antibody prepared against Atp11p reacted quantitatively with human samples. Levels of Atpaf1p in controls and patients with ATP-synthase deficiency are comparable. 2D electrophoresis revealed that Atpaf1p may exist as a dimer or asociated with another protein.