title: The rem mutations in the ATP-binding groove of the Rad3/XPD helicase lead to Xeroderma pigmentosum-Cockayne syndrome-like phenotypes.
abstract: The eukaryotic TFIIH complex is involved in Nucleotide Excision Repair and transcription initiation. We analyzed three yeast mutations of the Rad3/XPD helicase of TFIIH known as rem (recombination and mutation phenotypes). We found that, in these mutants, incomplete NER reactions lead to replication fork breaking and the subsequent engagement of the homologous recombination machinery to restore them. Nevertheless, the penetrance varies among mutants, giving rise to a phenotype gradient. Interestingly, the mutations analyzed reside at the ATP-binding groove of Rad3 and in vivo experiments reveal a gain of DNA affinity upon damage of the mutant Rad3 proteins. Since mutations at the ATP-binding groove of XPD in humans are present in the Xeroderma pigmentosum-Cockayne Syndrome (XP-CS), we recreated rem mutations in human cells, and found that these are XP-CS-like. We propose that the balance between the loss of helicase activity and the gain of DNA affinity controls the capacity of TFIIH to open DNA during NER, and its persistence at both DNA lesions and promoters. This conditions NER efficiency and transcription resumption after damage, which in human cells would explain the XP-CS phenotype, opening new perspectives to understand the molecular basis of the role of XPD in human disease.
authors.affiliation: Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Seville, Spain.
authors.forename: Emilia
authors.initials: E
authors.lastname: Herrera-Moyano
authors.affiliation: Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Seville, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Moriel-Carretero
authors.affiliation: Division of Biology and College of Arts & Sciences, Kansas State University, Manhattan, Kansas, United States of America.
authors.forename: Beth A
authors.initials: BA
authors.lastname: Montelone
authors.affiliation: Centro Andaluz de Biología Molecular y Medicina Regenerativa CABIMER, Universidad de Sevilla, Seville, Spain.
authors.forename: Andrés
authors.initials: A
authors.lastname: Aguilera
mesh_terms: D003057:Cockayne Syndrome / Q000235:genetics; D004249:DNA Damage; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D004260:DNA Repair; D006367:HeLa Cells; D006801:Humans; D009154:Mutation; D010641:Phenotype; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000528:radiation effects; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D051758:Transcription Factor TFIIH / Q000378:metabolism; D014466:Ultraviolet Rays; D014983:Xeroderma Pigmentosum / Q000235:genetics; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics
chemical_list: D029701:Saccharomyces cerevisiae Proteins; D051758:Transcription Factor TFIIH; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human