Transposition of the Zorro2 Retrotransposon Is Activated by Miconazole in Candida albicans

Abstract

Zorro2 is a member of a non-long terminal repeat (LTR) retrotransposon family in Candida albicans, but as yet no clear evidence has been provided to establish either transcription or transposition activity for Zorro2. In this study, the relative expression changes of two open reading frames in Zorro2, ORF19.7274 and ORF19.7275, were examined in response to miconazole (MCZ), and were found to be increased by this treatment. As well, the copy number and the transcripts of Zorro2 in MCZ-induced resistant daughter strains were increased compared to the parental strain, indicating that transposition of Zorro2 occurred during long-term MCZ treatment. Intriguingly, the transcription activity of Zorro2 retrotransposons was significantly inhibited when the cells were treated with MCZ together with antioxidant N-acetyl-L-cysteine (NAC). As both the level of intracellular reactive oxygen species (ROS) and the expression of genes involving DNA repair activated by MCZ were reduced when combined with the treatment of NAC, we propose that the damage caused by accumulation of ROS under MCZ stress is a major reason for the transcription and transposition activation of the Zorro2 retrotransposon.