The Candida albicans HWP2 protein is necessary for proper adhesion, biofilm formation and can complement a saccharomyces cerevisiae MUC1 null strain. (c2010)

Abstract

Candida albica7zs is a fungal pathogen of humans that is responsible for the majority of mucosal and systemic candidiasis. The host-pathogen interaction in C. albicans has been the subject of intense investigation as it is the primary step of infection. I-Iwp2 is a GPI-anchored cell wall protein that was previously shown to be necessary for hyphal and invasive growth on solid media. The purpose o f the current study is to further characterize the protein as far as its role in oxidative stress, sensitivity to cell wall disrupting agents, adhesion to human epithelial and endothelial cells, biofilm formation and chitin content. It appears that Hwp2 is necessary for proper oxidative stress tolerance, adhesion and bio film formation as an hJVp2 null is more susceptible to increasing doses of hydrogen peroxide, unable to adhere efficiently to epithelial and endotl1elial cell lines, and unable to form biofilms. Furthermore and according to the Candida genome database Muc1 is tl1e protein witl1 tl1e closest similarity-albeit slight- to Hwp2 in Saccharonryces cerevisiae. By transforming I-ITW2 into a mucl null strain we were able to complement tl1e lack of pseudohyphal growth of the mutant and confer upon S. cemvisiae adhesive properties. We thus show that in this case sequence sin1ilarity reflects true orthology.