title: p8/TTDA overexpression enhances UV-irradiation resistance and suppresses TFIIH mutations in a Drosophila trichothiodystrophy model.
abstract: 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.
authors.affiliation: Department of Developmental Genetics, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.
authors.forename: Javier
authors.initials: J
authors.lastname: Aguilar-Fuentes
authors.forename: Mariana
authors.initials: M
authors.lastname: Fregoso
authors.forename: Mariana
authors.initials: M
authors.lastname: Herrera
authors.forename: Enrique
authors.initials: E
authors.lastname: Reynaud
authors.forename: Cathy
authors.initials: C
authors.lastname: Braun
authors.forename: Jean Marc
authors.initials: JM
authors.lastname: Egly
authors.forename: Mario
authors.initials: M
authors.lastname: Zurita
mesh_terms: 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
chemical_list: D029721:Drosophila Proteins; D021122:Protein Subunits; C520555:mrn protein, Drosophila; D051758:Transcription Factor TFIIH