Cu transporter protein CrpF protects against Cu-induced toxicity in .

Cu is an essential trace element for cell growth and proliferation. However, excess of Cu accumulation leads to cellular toxicity. Thus, precise and tight regulation of Cu homeostasis processes, including transport, delivery, storage, detoxification, and efflux machineries, is required. Moreover, the maintenance of Cu homeostasis is critical for the survival and virulence of fungal pathogens. Cu homeostasis has been extensively studied in mammals, bacteria, and yeast, but it has not yet been well documented in filamentous fungi. In the present work, we investigated Cu tolerance in the filamentous fungus by analysing the Cu transporter coding gene , previously studied in . The expression studies demonstrated that is upregulated in the presence of Cu and its deletion leads to severe sensitivity to low levels of CuSO in . Targeted deletion of did not significantly alter the resistance of the fungus to macrophage killing, nor its pathogenic behaviour on the tomato plants. However, the targeted deletion mutant Δ showed increased virulence in a murine model of systemic infection compared to wild-type strain (wt).