PaGrg1 , a glucose-repressible gene of Podospora anserina that is differentially expressed during lifespan

Abstract

A loss-of-function mutation in Grisea, a gene of Podospora anserina that was previously shown to code for a copper-modulated transcription factor, leads to a significant increase in lifespan. In an attempt to identify and to isolate potential target genes controlled by GRISEA, a RT-differential-display screen was performed. This approach resulted in the identification of a gene, PaGrg1, that is differentially expressed in the wild-type and in the long-lived grisea mutant. In the mutant, transcript levels of PaGrg1 were found to be much lower than in the wild-type even if copper was added to the growth medium in amounts that revert the phenotype of this copper-uptake mutant to wild-type characteristics. PaGrg1 is a discontinuous gene with a single intron and encodes a protein of 71 amino acids sharing a high degree of sequence identity (65%) with the developmentally regulated, catabolite-repressed grg-1 gene of Neurospora crassa. Transcription of PaGrg1 increases upon carbon starvation indicating that PaGRG1 represents a putative stress protein. Transcript levels of PaGrg1 were found to increase during aging in both the wild-type strain and the long-lived mutant. However, even in the senescent stage of grisea, they are much lower than in juvenile cultures of the wild-type strain. The data suggest that threshold transcript levels of PaGrg1, and/ or additional unidentified genes which are controlled by GRISEA and which are subject to catabolite repression, are significantly involved in lifespan control. This conclusion is supported by the finding that, in contrast to the wild-type, the lifespan of grisea does not increase when cultures are grown on non-repressible carbon sources.

RNA-seq analyses of gene expression in the microsclerotia of Verticillium dahliae

“…CAZy genes significantly down-regulated included those encoding an alpha-galactosidase A VDAG_02431 (Additional file 5, #19), a glucan 1,3-beta-glucosidase VDAG_07185 (Additional file 5, #21), endoglucanase VDAG_06254 (Additional file 5, #17), glucan endo-1,3-alpha-glucosidase ( VDAG_04101 , 14-fold), and an endochitinase VDAG_08741 (Additional file 5, #9). The periplasmic trehalase VDAG_03038 and the glucose-repressive Grg1 [34] gene homolog VDAG_01467 were also up-regulated 10- and 13-fold (Additional file 4, #34 and #73, respectively).…”

Genetic and Functional Investigation of Zn2Cys6Transcription Factors RSE2 and RSE3 in Podospora anserina

“…It has been shown in N. crassa that the orthologue (grg-1 or ccg-1) is an abundantly expressed gene displaying complex regulation that involves clock control, light control, and metabolic control (35). It is intriguing that the expres- sion of grg1 decreased in the rse2 Y326D and rse3 G642V mutant strains that display a decreased life span (20), whereas its expression has been shown to be reduced in the long-lived mutant grisea and increased during senescence (36). It should be noted that in the three KO mutants, we failed to identify up-or downregulated gene(s) that could easily account for the increased longevity of the ⌬rse2, ⌬rse3, and ⌬rse2 ⌬rse3 mutants (20).…”

LongSAGE gene-expression profiling of Botrytis cinerea germination suppressed by resveratrol, the major grapevine phytoalexin

“…According to Kimpel & Osiewacz (1999), the nature of Grg1 as a gene encoding a fungal stress protein is supported in Neurospora crassa and Podospora anserina. However, in Botrytis cinerea, Grg1 has been found to be significantly upregulated at the onset of Arabidopsis thaliana leaf colonization ).…”