Identification of Trichophyton rubrum expressed genes involved in pH modulation

CAZZANIGA RA; SILVEIRA HC; GRAS DE; SANCHES PR; MAZUCATO M; ROSSI A; MARTINEZ-ROSSI NM

Asilomar

Conferencia; The 25th Fungal Genetics Conference at Asilomar; 2009

Genetics Society of America

Trichophyton rubrum is a dermatophyte fungus that infects human skin, hair and nails, utilizing keratin as nutrient source, secreting a variety of enzymes, such as keratinases, phosphatases, elastases, among others, which may be regulated by the extracellular pH. During infection, this dermatophyte must have metabolic machinery that allows environmental pH modulation, since it has to sense and adapt to the acidic pH of the skin, and to change environment pH to alkaline, enabling the maintenance of the infection. The aim of this study is the identification of T. rubrum differentially expressed genes in acid (pH 5.0) and alkaline (pH 8.0) pH. For this purpose, forward and reverse suppression subtractive hybridization (SSH) libraries were constructed, after cultivation of a T. rubrum strain on minimal media pH 5.0 or pH 8.0. After differential screening assays, the differentially expressed genes from both libraries were sequenced, annotated, and some genes were validated by Northern blot analyses. Taken together, these results contribute to the understanding of T. rubrum extracellular pH response, and the regulatory mechanisms possibly involved in pathogenhost interaction.