Regulation of Neurospora crassa MAP Kinase genes in response to exogenous phosphate levels

GRAS DE; SILVEIRA HC; LEAL J; PERES NT; SANCHES PR; MARTINEZ-ROSSI NM; ROSSI A

Edimburgo

Conferencia; 9th European Conference on Fungal Genetics; 2008

Federation of European Microbiological Societies

Nutrient uptake has important regulatory effects on fungal metabolism, physiology and growth. Although many proteins that function in inorganic phosphate (Pi) acquisition, storage and utilization have been identified, the molecular details of their regulation are not well understood. Under the action of regulatory genes nuc-2, preg, pgov and nuc-1, Neurospora crassa synthesizes a number of phosphatases to scavenge Pi from the environment in response to Pi starvation. Under limiting Pi, NUC-2 inhibits the action of PREG/PGOV complex, allowing the translocation of transcription factor NUC-1 into the nucleus and expression of the Pi-repressible phosphatases. Subtractive hybridizations allowed the identification of two transcripts coding for MAP Kinases (NCU02393 and NCU07024) overexpressed in a strain of N. crassa carrying a loss-of-function mutation in the nuc-2 gene. To further understand the role of these MAP Kinases in the acquisition of Pi, we also carried out a series of Northern blot and semi-quantitative RT-PCR experiments with various strains carrying mutations in genes involved in the phosphate acquisition pathway, which revealed novel aspects of this regulatory network.