INVESTIGADORES
GRAS Diana Ester
congresos y reuniones científicas
Título:
Identification of genes up regulated in the palA1 mutant strain of Aspergillus nidulans
Autor/es:
SILVA EM; FREITAS JS; GRAS DE; LEAL J; SQUINA FM; SILVEIRA HC; MARTINEZ-ROSSI NM; ROSSI A
Lugar:
Asilomar
Reunión:
Conferencia; 24th Fungal Genetics Conference at Asilomar; 2007
Institución organizadora:
Genetics Society of America
Resumen:
The conserved PacC signal transduction pathway mediates many metabolic events involved in ambient pH sensing in Aspergillus nidulans, and it is widely accepted that it governs the response to neutral-to-alkaline pH. The pacC gene codes for a Zn-finger transcription factor, and the six pal genes (palA, B, C, F, H, and I) are putative members of a signaling cascade, which promotes the proteolytic activation of PacC in alkaline environment. The PalA protein interacts with the YPXL/I motifs in PacC, what is required for the action of PalB, a calpain-like protease. Thus, whatever the growth pH is, palA1 mutation should cause an acidity-mimicking phenotype. This model implies that loss-of-function mutation in any of the six pal genes shall lead to a wild-type acidic growth phenotype regardless on the ambient pH, what was not observed in the palA1 mutant strain. Employing suppression subtractive hybridization, we identified genes up-regulated in the palA1 mutant strain of A. nidulans grown in low-Pi medium, pH 5.0, whose expression should occur only at alkaline pH, as is the case for the expression of the phospholipase C gene. This result shows a derangement in the gene expression profile at pH 5.0, indicating that the palA gene is functional at acidic pH and, therefore, the palA1 mutation did not cause an acidic-mimicking phenotype.