Identification and characterization of HAP1, a YAP1 homologue, in the fungus Histoplasma capsulatum

Blain Tesfaye Fente, The College of Wooster

Abstract

Histoplasma capsulatum is the fungus that causes the respiratory disease Histoplasmosis. Its pathogenicity is linked to its ability to survive in the host macrophage cells, phagocytic white blood cells that release reactive oxygen species (ROS) and degradative enzymes to lyse engulfed foreign materials. To study how H. capsulatum survives in this harsh environment, we predicted the presence of a YAP1 homologue in the two North American (NAm1 and NAm2) strains of H. capsulatum. YAP1 is a transcription factor found in Saccharomyces cerevisiae that has been shown to be responsible in regulating gene expression to effectively control the redox environment. Sequence analysis has been used to identify a homologue with 2265bp-ORF, and 1665bp coding sequence. The gene was named HAP1, for H. capsulatum AP-1. The HAP1 gene encodes for a 555 amino acid protein. The 2265bp-ORF has been cloned out of NAm1 and NAm2. This ORF has been cloned into entry clones. It will be expressed in yap1 mutant strains (S. cerevisiae with the YAP1 gene knockout) and wild type S. cerevisiae. These transformed S. cerevisiae will be exposed to increasing concentration of H2O2 to check for functional complementation of HAP1 for YAP1.