Gene expression of 70 kDa heat shock protein ofCandida albicans: transcriptional activation and response to heat shock

CaHSP70 (70 kDa heat shock protein) is a highly immunogenic protein of Candida albicans. We have studied heat shock-induced expression of the CaHSP70 gene under germ tube-inductive and non-inductive conditions. The CaHSP70 upstream regulatory region was cloned and sequenced. It contains at least three heat shock elements (HSEs), specific DNA sequences that are bound by the heat shock transcription factor (HSF), and one stress response element (STRE), which is an upstream activator sequence (UAS) that causes transcription activation under stress. The binding of HSF to HSE in the CaHSP70 promoter region is constitutive, although the mobility of protein/DNA complexes is altered after heat shock. The CaHSP70 promoter was cloned into a lacZ reporter plasmid, and was able to respond to heat shock in C. albicans as well as in Saccharomyces cerevisiae.