Tec1p-independent activation of a hypha-associated Candida albicans virulence gene during infection.

The Tec1p transcription factor is involved in the expression of hypha-specific genes in Candida albicans. Although the induction of the hypha-associated SAP5 gene by serum in vitro depends on Tec1p, deletion of all Tec1p binding site consensus sequences from the SAP5 promoter did not affect its activation. In two different animal models of candidiasis, the SAP5 promoter was induced even in a Deltatec1 deletion mutant, demonstrating that the requirement for Tec1p in gene expression in C. albicans depends on the environmental conditions within the host.