p8/TTDA overexpression enhances UV-irradiation resistance and suppresses TFIIH mutations in a Drosophila trichothiodystrophy model.
Mutations in certain subunits of the DNA repair/transcription factor complex TFIIH are linked to the human syndromes xeroderma pigmentosum (XP), Cockayne's syndrome (CS), and trichothiodystrophy (TTD). One of these subunits, p8/TTDA, interacts with p52 and XPD and is important in maintaining TFIIH stability. Drosophila mutants in the p52 (Dmp52) subunit exhibit phenotypic defects similar to those observed in TTD patients with defects in p8/TTDA and XPD, including reduced levels of TFIIH. Here, we demonstrate that several Dmp52 phenotypes, including lethality, developmental defects, and sterility, can be suppressed by p8/TTDA overexpression. TFIIH levels were also recovered in rescued flies. In addition, p8/TTDA overexpression suppressed a lethal allele of the Drosophila XPB homolog. Furthermore, transgenic flies overexpressing p8/TTDA were more resistant to UV irradiation than were wild-type flies, apparently because of enhanced efficiency of cyclobutane-pyrimidine-dimers and 6-4 pyrimidine-pyrimidone photoproducts repair. This study is the first using an intact higher-animal model to show that one subunit mutant can trans-complement another subunit in a multi-subunit complex linked to human diseases.
Aguilar-Fuentes
Javier
J
Department of Developmental Genetics, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
Fregoso
Mariana
M
Herrera
Mariana
M
Reynaud
Enrique
E
Braun
Cathy
C
Egly
Jean Marc
JM
Zurita
Mario
M
D000818:Animals; D004195:Disease Models, Animal; D015536:Down-Regulation; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects*; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D006801:Humans; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D011836:Radiation Tolerance; D013489:Suppression, Genetic; D051758:Transcription Factor TFIIH / Q000235:genetics* / Q000378:metabolism; D054463:Trichothiodystrophy Syndromes / Q000235:genetics* / Q000378:metabolism; D014466:Ultraviolet Rays
D029721:Drosophila Proteins; D021122:Protein Subunits; C520555:mrn protein, Drosophila; D051758:Transcription Factor TFIIH