Sahu Satya Ranjan, Parida Sushree Subhashree, Utkalaja Bhabasha Gyanadeep, Nayak Shreenath, Dalei Amrita, Acharya Narottam
Laboratory of Genomic Instability and Diseases, Department of Infectious Disease Biology, Institute of Life Sciences, Bhubaneswar, India.
Regional Center of Biotechnology, Faridabad, India.
Mol Microbiol. 2025 Jul 17. doi: 10.1111/mmi.70013.
Translesion DNA synthesis (TLS) is a fundamental biological process that enables DNA replication through various lesions to ensure genome stability and to prevent cell death due to replication fork collapse. Rev1, a member of Y-family DNA polymerase (Pol), functions in concert with a B-family enzyme Polζ in promoting TLS through various lesions. Interestingly, for such a function, the catalytic activity of Rev1 seems to be dispensable in Saccharomyces cerevisiae. Unlike Polζ, which possesses robust DNA polymerase activity, biochemical assays suggest that Rev1 predominantly incorporates a "C" opposite any templating residues, but the biological relevance of this activity of Rev1 remains elusive. Here we characterized Rev1 from Candida albicans, an opportunistic fungal pathogen responsible for maximum casualties due to systemic candidiasis in immunosuppressed individuals. Concerted genetic analyses of several Rev1 mutants in various DNA-damaging conditions suggested that in most lesion bypasses except 4-NQO-induced DNA lesions, the catalytic role of Rev1 is not important. However, simultaneous interactions of BRCT and the C-terminal domain of Rev1 with PCNA and Polζ, respectively, enable Rev1 to be essential during TLS. DNA damage recovery and mutagenesis assays further confirmed the lesion-specific roles of various domains of Rev1. Contrary to ex vivo data, animal studies suggested that CaRev1 is dispensable for systemic candidiasis development. We discuss the possible involvement of other TLS DNA polymerases in DNA damage response while C. albicans replicates and establishes itself in the host.
跨损伤DNA合成（TLS）是一种基本的生物学过程，它能够使DNA通过各种损伤进行复制，以确保基因组稳定性，并防止因复制叉坍塌而导致的细胞死亡。Rev1是Y家族DNA聚合酶（Pol）的成员之一，它与B家族酶Polζ协同作用，促进通过各种损伤的TLS。有趣的是，对于这样一种功能，Rev1的催化活性在酿酒酵母中似乎是可有可无的。与具有强大DNA聚合酶活性的Polζ不同，生化分析表明，Rev1主要在任何模板残基的对面掺入一个“C”，但Rev1这种活性的生物学相关性仍然难以捉摸。在这里，我们对白色念珠菌的Rev1进行了表征，白色念珠菌是一种机会性真菌病原体，在免疫抑制个体中因系统性念珠菌病导致了最多的伤亡。对几种Rev1突变体在各种DNA损伤条件下进行的协同遗传分析表明，在除4 - NQO诱导的DNA损伤外的大多数损伤绕过过程中，Rev1的催化作用并不重要。然而，Rev1的BRCT结构域和C末端结构域分别与增殖细胞核抗原（PCNA）和Polζ同时相互作用，使得Rev1在TLS过程中变得至关重要。DNA损伤恢复和诱变分析进一步证实了Rev1各个结构域的损伤特异性作用。与体外数据相反，动物研究表明CaRev1对于系统性念珠菌病的发展是可有可无的。我们讨论了在白色念珠菌在宿主体内复制并定殖时，其他TLS DNA聚合酶可能参与DNA损伤反应的情况。
