Functional complementation of a membrane transport deficiency in Saccharomyces cerevisiae by recombinant ND4 fusion protein.
ND4 is a mitochondrially encoded component of NADH dehydrogenase (Complex I) of the respiratory chain. A cDNA encoding a fusion protein comprised of the N-terminus of GAL10 of Saccharomyces cerevisiae and an N-terminally truncated form of human ND4 was isolated by its ability to functionally complement the thymidine transport deficiency of S. cerevisiae grown under conditions of thymidylate starvation. Epitope-tagged GAL10-ND4 was shown by immunological methods to be present in the plasma membranes of yeast expressing the GAL10-ND4 encoding cDNA. The ability of the GAL10-ND4 fusion protein to induce uptake of thymidine raises the possibility that native ND4, which is predicted to have 12 transmembrane domains, may function as a transporter or channel in the mitochondrial inner membrane.
Hogue
D L
DL
BC Cancer Research Centre, Vancouver, Canada.
Ellison
M J
MJ
Vickers
M
M
Cass
C E
CE
D000595:Amino Acid Sequence; D001483:Base Sequence; D001692:Biological Transport / Q000235:genetics; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D018076:DNA, Complementary / Q000302:isolation & purification; D005656:Fungal Proteins / Q000235:genetics*; D005690:Galactose / Q000235:genetics; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009245:NADH Dehydrogenase / Q000235:genetics*; D012333:RNA, Messenger / Q000096:biosynthesis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D018076:DNA, Complementary; D005656:Fungal Proteins; C098483:NADH dehydrogenase subunit 4; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D009245:NADH Dehydrogenase; D005690:Galactose