INVESTIGADORES
GRAS Diana Ester
congresos y reuniones científicas
Título:
Transcription factor PacC also has metabolic functions specific to acid pH sensing by the dermatophyte Trichophyton rubrum
Autor/es:
SILVEIRA HC; GRAS DE; SANCHES PR; ROSSI A; MARTINEZ-ROSSI NM
Lugar:
Edimburgo
Reunión:
Conferencia; 9th European Conference on Fungal Genetics; 2008
Institución organizadora:
Federation of European Microbiological Societies
Resumen:
Dermatophytosis is commonly caused by fungi that parasite human skin and nails. Although several factors contribute to their pathogenicity, the successful initiation of infection depends on the capacity of the infecting dermatophyte to sense and overcome the acid pH of the skin. Thus, it is important to understand the metabolic responses that govern the acid pH signaling in dermatophytes. To identify genes supposedly expressed in the initial steps of infection, a suppression subtractive hybridization (SSH) was used between RNA isolated from the H6 strain of the dermatophyte T. rubrum exposed to pH 5.0 and to pH 8.0. This study reveled genes involved in diverse cellular processes as, for example, defense and virulence, protein synthesis and cell transport, which are significantly up-regulated in the H6 strain exposed to pH 5.0. Among these, we confirmed by Northern blot analyses the over-expression of the genes coding for carboxipeptidase S1, acetamidase, aconitase, fatty acid desaturase, TINA, amino acid permease, elongation factor 1-alpha, 60S ribosomal protein L10 and an hypothetical protein. It is worth noting that the expression of at least three of these transcripts is lowered in the pacC-1 mutant strain of T. rubrum (pacC gene disrupted) exposed to pH 5.0, indicating that protein PacC may also have metabolic functions specific to acidic growth pH. The pacC gene encodes a protein homologous to the PacC/Rim101p transcriptional regulator of the conserved route of pH signaling, whose functionality was previously described as exclusive to alkaline pH. We also showed previously that disruption of gene pacC was correlated with a decreased ability of the pacC-1 mutant strain to grow on human nail fragments as the only source of nutrition, which is consistent with the fact that keratinolytic proteases are under the regulation of gene pacC.