Transcription analysis using high-density micro-arrays of Aspergillus nidulans wild-type and creA mutant during growth on glucose or ethanol

Mogensen, Jesper Mølgaard; Nielsen, Henrik Bjørn; Hofmann, Gerald; Nielsen, Jens

doi:10.1016/j.fgb.2006.03.003

Cited by 61 publications

(63 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, our data show that the carbon catabolite repressor CRE1 is-in contrast-required for full induction by lactose, rather than repressing its expression. A positive effect of A. nidulans CreA on gene expression has been reported previously (22) and is also observed for several other T. reesei genes (T. Portnoy et al, submitted for publication).…”

Section: Discussionsupporting

confidence: 75%

Differential Regulation of the Cellulase Transcription Factors XYR1, ACE2, and ACE1 in Trichoderma reesei Strains Producing High and Low Levels of Cellulase

et al. 2011

View full text Add to dashboard Cite

Due to its capacity to produce large amounts of cellulases, Trichoderma reesei is increasingly being investigated for second-generation biofuel production from lignocellulosic biomass. The induction mechanisms of T. reesei cellulases have been described recently, but the regulation of the genes involved in their transcription has not been studied thoroughly. Here we report the regulation of expression of the two activator genes xyr1 and ace2, and the corepressor gene ace1, during the induction of cellulase biosynthesis by the inducer lactose in T. reesei QM 9414, a strain producing low levels of cellulase (low producer). We show that all three genes are induced by lactose. xyr1 was also induced by D-galactose, but this induction was independent of D-galactose metabolism. Moreover, ace1 was carbon catabolite repressed, whereas full induction of xyr1 and ace2 in fact required CRE1. Significant differences in these regulatory patterns were observed in the high-producer strain RUT C30 and the hyperproducer strain T. reesei CL847. These observations suggest that a strongly elevated basal transcription level of xyr1 and reduced upregulation of ace1 by lactose may have been important for generating the hyperproducer strain and that thus, these genes are major control elements of cellulase production.

show abstract

Section: Discussionsupporting

confidence: 75%

Differential Regulation of the Cellulase Transcription Factors XYR1, ACE2, and ACE1 in Trichoderma reesei Strains Producing High and Low Levels of Cellulase

et al. 2011

View full text Add to dashboard Cite

show abstract

“…In fungi the utilization of alternative carbon sources in the presence of glucose is generally downregulated by a carbon catabolite repression system. In aspergilli this repression system is governed mainly by the DNA-binding protein CreA (15,33), whereas in Saccharomyces cerevisiae Mig1p plays a major role in carbon catabolite repression (21). Studies of S. cerevisiae revealed that the hexokinase Hxk2p additionally participates in the regulation of alternative carbon utilization (23) and fermentative growth in the presence of glucose (39).…”

mentioning

confidence: 99%

Aspergillus fumigatus Catalytic Glucokinase and Hexokinase: Expression Analysis and Importance for Germination, Growth, and Conidiation

Fleck

Brock

2010

Eukaryot Cell

View full text Add to dashboard Cite

Fungi contain several hexokinases, which are involved either in sugar phosphorylation or in carbon source sensing. Glucose and fructose phosphorylations appear to rely exclusively on glucokinase and hexokinase. Here, we characterized the catalytic glucokinase and hexokinase from the opportunistic human pathogen Aspergillus fumigatus and showed that both enzymes display different biochemical properties and play different roles during growth and development. Glucokinase efficiently activates glucose and mannose but activates fructose only to a minor extent. Hexokinase showed a high efficiency for fructose activation but also activated glucose and mannose. Transcript and activity determinations revealed high levels of glucokinase in resting conidia, whereas hexokinase was associated mainly with the mycelium. Consequentially, a glucokinase mutant showed delayed germination at low glucose concentrations, whereas colony growth was not overly affected. The deletion of hexokinase had only a minor impact on germination but reduced colony growth, especially on sugar-containing media. Transcript determinations from infected mouse lungs revealed the expression of both genes, indicating a contribution to virulence. Interestingly, a double-deletion mutant showed impaired growth not only on sugars but also on nonfermentable nutrients, and growth on gluconeogenic carbon sources was strongly suppressed in the presence of glucose. Furthermore, the glkA hxkA deletion affected cell wall integrity, implying that both enzymes contribute to the cell wall composition. Additionally, the absence of either enzyme deregulated carbon catabolite repression since mutants displayed an induction of isocitrate lyase activity during growth on glucose-ethanol medium. Therefore, both enzymes seem to be required for balancing carbon flux in A. fumigatus and are indispensable for growth under all nutritional conditions.

show abstract

“…This may explain that higher enzyme activities found in BF could be related to transcriptional activation by XlnR protein; however, the lack of XlnR activation in SF is not clear but it may suggest different regulatory mechanism and probably synergistic with XlnR in biofilms. A differential transcription analysis using xlnR and creA mutants in SF and BF could clarify such regulatory mechanisms (Mogensen et al 2006). A.…”

Section: Resultsmentioning

confidence: 99%

Expresión diferencial de los genes de algunas enzimas lignocelulolíticas en biopelículas de Aspergillus niger

et al. 2008

View full text Add to dashboard Cite

Transcription analysis using high-density micro-arrays of Aspergillus nidulans wild-type and creA mutant during growth on glucose or ethanol

Cited by 61 publications

References 49 publications

Differential Regulation of the Cellulase Transcription Factors XYR1, ACE2, and ACE1 in Trichoderma reesei Strains Producing High and Low Levels of Cellulase

Differential Regulation of the Cellulase Transcription Factors XYR1, ACE2, and ACE1 in Trichoderma reesei Strains Producing High and Low Levels of Cellulase

Aspergillus fumigatus Catalytic Glucokinase and Hexokinase: Expression Analysis and Importance for Germination, Growth, and Conidiation

Expresión diferencial de los genes de algunas enzimas lignocelulolíticas en biopelículas de Aspergillus niger

Contact Info

Product

Resources

About