Adhesive and mammalian transglutaminase substrate properties of Candida albicans Hwp1

The pathogenesis of candidiasis involves invasion of host tissues by filame ntous forms of the opportunistic yeast Candida albicans. Morphology-specifi c gene products may confer proinvasive properties. A hypha-specific surface protein, Hwp1, with similarities to mammalian small proline-rich proteins was shown to serve as a substrate for mammalian transglutaminases. Candida albicans strains lacking Hwp1 were unable to form stable attachments to hum an buccal epithelial cells and had a reduced capacity to cause systemic can didiasis in mice. This represents a paradigm for microbial adhesion that im plicates essential host enzymes.