Filamentous growth of Candida albicans in response to physical environmental cues and its regulation by the unique CZF1 gene

Hyphal growth in the opportunistic fungal pathogen Candida albicans is believed to contribute to the virulence of the organism by promoting penetration of fungal cells into host tissue. In this study, stimulation of hyphal growth by a feature of the physical environment was demonstrated. Specifically, growth of cells embedded within a matrix promoted the formation of hyphae. The CZF1 gene, encoding a putative transcription factor, was shown to be involved in the regulation of hyphal growth under certain conditions, including embedded conditions. Ectopic expression of CZF1 in embedded cells promoted the rapid formation of hyphae. Elimination of CZF1 and CPH1, encoding a homologue of the Saccharomyces cerevisiae Ste12p transcription factor, led to a pronounced defect in filamentous growth of embedded cells. Elimination of CZF1 alone led to a moderate defect in hyphal growth under some conditions, including embedded conditions. Hyphal morphogenesis in response to matrix embedding may occur in the opportunistic pathogen, C. albicans, to promote invasion of fungal cells into host tissue.