Valine 181 is critical for the nucleotide exchange activity of human mitochondrial ADP/ATP carriers in yeast.
We isolated yeast Saccharomyces cerevisiae cells transformed with one of the three human adenine 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 HANC that led to replacement of valine 181 located in the fourth transmembrane segment by methionine or phenylalanine. Tolerance of this position toward substitution with various amino acids was systematically investigated, and since HANC/V181M was among the most efficient in growth complementation, it was more extensively studied. Here we show that increased growth capacities were associated with higher ADP/ATP exchange activities and not with higher human carrier amount in yeast mitochondria. These results are discussed in the light of the bovine Ancp structure, that shares more than 90% amino acid identity with Hancps, and its interaction with the lipid environment.
De Marcos Lousa
Carine
C
Laboratoire de Physiologie Moléculaire et Cellulaire, IBGC-CNRS, UMR 5095, 1 rue Camille Saint-Saëns, 33077 Bordeaux Cedex, France.
Trézéguet
Véronique
V
David
Claudine
C
Postis
Vincent
V
Arnou
Bertrand
B
Pebay-Peyroula
Eva
E
Brandolin
Gérard
G
Lauquin
Guy J-M
GJ
D033741:Adenine Nucleotide Translocator 1 / Q000235:genetics / Q000378:metabolism*; D033742:Adenine Nucleotide Translocator 2 / Q000235:genetics / Q000378:metabolism*; D033781:Adenine Nucleotide Translocator 3 / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D002417:Cattle; D005816:Genetic Complementation Test; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D008715:Methionine / Q000235:genetics; D008928:Mitochondria / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D000226:Mitochondrial ADP, ATP Translocases / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D014466:Ultraviolet Rays; D014633:Valine / Q000235:genetics
D033741:Adenine Nucleotide Translocator 1; D033742:Adenine Nucleotide Translocator 2; D033781:Adenine Nucleotide Translocator 3; D020662:Guanine Nucleotide Exchange Factors; D029701:Saccharomyces cerevisiae Proteins; D000226:Mitochondrial ADP, ATP Translocases; D008715:Methionine; D014633:Valine