Molecular characterisation of a NADH ubiquinone oxidoreductase subunit 5 from Schistosoma mansoni and inhibition of mitochondrial respiratory chain function by testosterone.
Complementary DNA, encoding the mitochondrial enzyme NADH-ubiquinone oxidoreductase subunit 5 (SmND5) of the human parasite Schistosoma mansoni was isolated by screening a S. mansoni cDNA library with a human androgen receptor (hAR) cDNA probe. The complete nucleotide and deduced aminoacid sequences of SmND5 were determined. Southern blot analysis revealed the occurrence of a single copy gene for SmND5 and by means of RT-PCR, it was shown that sex- and stage-specific expression of SmND5 occurred. In order to establish a functional relationship between the mitochondrial enzyme and the androgen receptor, the effects of testosterone were compared to those of classical respiratory chain inhibitors, using adult schistosome and beef heart submitochondrial particles. Physiological concentrations of testosterone were able to inhibit the maintenance of proton gradient across the mitochondrial membranes, as well as ATP synthesis. The steroid was found to be cytotoxic to the larvae, but not to adult schistosomes. A model is proposed to explain the observed in vivo testosterone-related differences in worm burdens, in experimental chronic infections.
Fantappié
M R
MR
Departamento de Bioquímica Médica ICB/CCS, Universidade Federal do Rio de Janeiro-Ilha do Fundão, Rio de Janeiro, Brasil.
Galina
A
A
Luís de Mendonça
R
R
Furtado
D R
DR
Secor
W E
WE
Colley
D G
DG
Corrêa-Oliveira
R
R
Freeman
G
G
Tempone
A J
AJ
Lannes de Camargo
L
L
Rumjanek
D F
DF
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001516:Bees / Q000201:enzymology; D017173:Caenorhabditis elegans / Q000201:enzymology; D002417:Cattle; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary; D042967:Electron Transport Complex I; D015723:Gene Library; D006801:Humans; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D008969:Molecular Sequence Data; D009247:NADH, NADPH Oxidoreductases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects; D011944:Receptors, Androgen / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012550:Schistosoma mansoni / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013367:Submitochondrial Particles / Q000187:drug effects / Q000378:metabolism; D013739:Testosterone / Q000494:pharmacology
D018076:DNA, Complementary; D011944:Receptors, Androgen; D011994:Recombinant Proteins; D013739:Testosterone; D009247:NADH, NADPH Oxidoreductases; D042967:Electron Transport Complex I