Abf1 participates in the response to DNA damage and replicative stress in Candida glabrata (Nakaseomyces glabratus)

ARS binding factor 1 (Abf1) is a DNA-binding protein found in various fungal species. In the opportunistic pathogenic fungus Candida glabrata (Nakaseomyces glabratus), Abf1 (CgAbf1) is encoded by the ABF1 gene. Our research has demonstrated that CgAbf1 is essential for the viability of C. glabrata and is involved in the subtelomeric silencing of several EPA genes, which encode adhesins that mediate adhesion to epithelial cells, underscoring its significance as a virulence factor in this pathogen. Our previous findings established that both the depletion and overexpression of CgAbf1 result in growth defects and induce a delay in cell cycle progression. In this work, we wanted to determine if CgAbf1 is involved in the response to replicative and DNA damage stresses. We analyzed the CgAbf1 protein levels under these conditions and the activity of the CgABF1 promoter and found that CgAbf1 negatively regulates its own transcription. A Bimolecular Fluorescence Complementation assay showed that CgAbf1 localizes to the nucleus and forms homodimers. We also found that CgAbf1 is involved in the survival to DNA damage caused by UV light and we demonstrated that Saccharomyces cerevisiae Abf1 (ScAbf1) can complement the lethality of the C. glabrata abf1∆ strain.