文摘
We isolated yeast Saccharomyces cerevisiae cells transformed with one of the three humanadenine nucleotide carrier genes (HANC) that exhibited higher growth capacity than previously observed.The HANC genes were isolated from these clones, and we identified two independent mutations of HANCthat led to replacement of valine 181 located in the fourth transmembrane segment by methionine orphenylalanine. Tolerance of this position toward substitution with various amino acids was systematicallyinvestigated, and since HANC/V181M was among the most efficient in growth complementation, it wasmore extensively studied. Here we show that increased growth capacities were associated with higherADP/ATP exchange activities and not with higher human carrier amount in yeast mitochondria. Theseresults are discussed in the light of the bovine Ancp structure, that shares more than 90% amino acididentity with Hancps, and its interaction with the lipid environment.