Transcriptional profiling of Saccharomyces cerevisiae cells under adhesion-inducing conditions.

The ability to adhere to other cells is one of the most prominent determinants of fungal pathogenicity. Thus, adherence of fungi to human tissues or plastics triggers hospital-acquired fungal infections, which are an increasing clinical problem, especially in immunocompromised persons. In the model fungus Saccharomyces cerevisiae adhesion can be induced by starvation for amino acids, and depends on the transcriptional activator of the general amino acid control system, Gcn4p. However, not much is known about the transcriptional program that mediates adhesive growth under such conditions. In this study, we present a genome-wide transcriptional analysis of Sigma1278b yeast cells that were subjected to adhesion-inducing conditions imposed by amino acid starvation. Twenty-two novel genes were identified as inducible by amino acid starvation; 72 genes belonging to different functional groups, which were not previously known to be regulated by Gcn4p, require Gcn4p for full transcriptional induction under adhesion-inducing conditions. In addition, several genes were identified in Sigma1278b cells that were inducible by amino acid starvation in a Gcn4p-independent manner. Our data suggest that adhesion of yeast cells induced by amino acid starvation is regulated by a complex, Sigma1278b-specific transcriptional response.