Analysis of the response of Candida albicans cells to Silver(I)

Abstract

The response of the pathogenic yeast Candida albicans to the silver(I) perchlorate salt (AgClO₄) was assessed. By employing an anti-phospho-p38 MAPK antibody, dual phosphorylation of a high osmolarity protein (Hog1p) in C. albicans in the presence of AgClO₄ was demonstrated. Phosphorylation of C. albicans Hog1p in response to hydrogen peroxide or AgClO₄ resulted in the translocation of this mitogen-activated protein (MAP) kinase to the nucleus. Nuclear translocation of C. albicans activating protein-1 (Cap1p) was demonstrated by Western blot analysis and detected using polyclonal anti-Cap1p antibody. Upon AgClO₄-induced translocation of Cap1p there was a concomitant activation of genes coding for glutathione reductase-1 and Mn-superoxide dismutase but no increase in the expression of flavin oxidoreductase or mitochondrial processing protease was recorded. In addition, exposure to AgClO₄ increased the activity of superoxide dismutase, glutathione reductase and catalase. The activation of C. albicans oxidative stress response genes and enzymes following exposure to AgClO₄ is evidence of the generation of oxidative stress within this medically important yeast.

Keywords:

• antifungal
• Candida albicans
• oxidative stress in yeast
• silver(I)
• Hog1p
• Cap1p

Acknowledgements

This work was supported by funding from the Higher Education Authority of Ireland through the Programme for Research in Third Level Institutes III.

Declaration of interest: The authors have no conflicts of interest to declare. The authors alone are responsible for the content and writing of this paper.

This paper was first published online on Early Online on 29 September 2009.