Identification of new Neurospora crassa genes under regulation of the transcription factor NUC-1 in response to pi starvation

LEAL J; SQUINA FM; FREITAS JS; SILVA EM; SILVEIRA HC; GRAS DE; SANCHES PR; MARTINEZ-ROSSI NM; ROSSI A

Salvador

Conferencia; XXXVI Annual Meeting of the SBBq and 10th IUBMB Conference Infectious Diseases: Biochemistry of Parasites, Vectors and Hosts; 2007

Sociedade Brasileira de Bioquímica e Biologia Molecular

Changes in environmental factors such as availability nutrients and pH trigger temporary modifications in patterns of gene expression. 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 signals of Pi starvation. Under limiting Pi, NUC-2 inhibits the action of PREG/PGOV complex, allowing the translocation of the transcription factor NUC-1 into the nucleus, and consequently, the expression of phosphatases. Here we identify genes differentially expressed in nuc-1RIP mutant, we employed suppression subtractive hybridization (SSH) between RNA isolated from the 74A and nuc-1RIP mutant strains of N. crassa grown in low Pi, pH 8.0. The expression of cDNAs clones was analyzed using macro-arrays dot-blot. Two-hundred transcripts differentially expressed in the nuc-1RIP mutant were sequenced and 31 unigenes were identified, with 29 codifying for putative proteins involved in diverse cellular processes. Some transcripts were confirmed by Northern Blot, as those that encode the HEX-1 (NCU08332.3) and NMT-1 (NCU09345.3) proteins, which were respectively up and down regulated in the nuc-1RIP mutant. Our results show that in addition to its role in phosphate acquisition, the nuc-1 gene is involved in the regulation of other metabolic processes