Abstract

DNA damage response has a central role in the maintenance of genomic integrity while mutations in related genes may result in a range of disorders, including neoplasic formations. The uvsZ1 characterized in this report is a novel uvs mutation in Aspergillus nidulans, resulting in a nucleotide excision repair (NER) phenotype: UV-sensitivity before DNA synthesis (quiescent cells), high UV-induced mutation frequency and probable absence of involvement with mitotic and meiotic recombinations. The mutation is recessive and non-allelic to the previously characterized uvsA101 mutation, also located on the paba-y interval on chromosome I. uvsZ1 showed wild-type sensitivity to MMS, which suggests non-involvement of this mutation with BER. Epitasis tests showed that the uvsZ gene product is probably involved in the same repair pathways as UVSB or UVSH proteins. Although mutations in these proteins result in an NER phenotype, UVSB is related with cell cycle control and UVSH is associated with the post-replicational repair pathway. The epistatic interaction among uvsZ1 and uvsB413 and uvsH77 mutations indicates that different repair systems may be related with the common steps of DNA damage response in Aspergillus nidulans.

• Keywords: uvs mutation; DNA repair; UV light; alkylating agents; Aspergillus nidulans