CreA modulates the XlnR-induced expression on xylose of Aspergillus niger genes involved in xylan degradation.

The expression of the feruloyl esterase gene faeA, the alpha-glucuronidase gene aguA, the endoxylanase gene xlnB, and the beta-xylosidase gene xlnD from Aspergillus niger on xylose was studied in a wild-type strain and in a CreA mutant. A decrease in expression of all four genes was observed with increasing xylose concentrations in the wild-type strain, whereas expression levels in the CreA mutant were not influenced. The results in the wild type indicated that xylose concentrations higher than 1 mM resulted in repression of the expression of the xylanolytic genes tested mediated by the carbon catabolite repressor protein CreA. On xylose, the expression levels of the xylanolytic genes were therefore not only determined by induction via XlnR, but also by repression via CreA. The genes tested were not influenced to the same extent by XlnR or CreA, resulting in specific expression levels and patterns for each individual gene.

[1]  J. Visser,et al.  Carbon repression in Aspergilli. , 1997, FEMS microbiology letters.

[2]  A. van Belkum,et al.  General primer-mediated PCR for detection of Aspergillus species , 1994, Journal of clinical microbiology.

[3]  P. Thonart,et al.  Study on the production of a xylanolytic complex frompenicillium canescens 10-10c , 1997, Applied biochemistry and biotechnology.

[4]  E. Cornillot,et al.  The CreA Repressor Is the Sole DNA-binding Protein Responsible for Carbon Catabolite Repression of the alcA Gene inAspergillus nidulans via Its Binding to a Couple of Specific Sites* , 1998, The Journal of Biological Chemistry.

[5]  S. Zeilinger,et al.  Carbon catabolite repression of xylanase I (xyn1) gene expression in Trichoderma reesei , 1996, Molecular microbiology.

[6]  J. Kelly,et al.  Analysis of mutations in the creA gene involved in carbon catabolite repression in Aspergillus nidulans. , 1996, Canadian journal of microbiology.

[7]  M. Penttilä,et al.  The α-glucuronidase-encoding gene of Trichoderma reesei , 1996 .

[8]  P. Punt,et al.  Kinetics of mRNA and protein synthesis of genes controlled by the 1,4-beta-endoxylanase A promoter in controlled fermentations of Aspergillus awamori , 1996, Applied and environmental microbiology.

[9]  S. Zeilinger,et al.  Crel, the carbon catabolite repressor protein from Trichoderma reesei , 1995, FEBS letters.

[10]  J. Visser,et al.  Structure and regulation of an Aspergillus xylanase gene. , 1992 .

[11]  A. Törrönen,et al.  The Two Major Xylanases from Trichoderma Reesei: Characterization of Both Enzymes and Genes , 1992, Bio/Technology.

[12]  C. Scazzocchio,et al.  Two different, adjacent and divergent zinc finger binding sites are necessary for CREA‐mediated carbon catabolite repression in the proline gene cluster of Aspergillus nidulans. , 1994, The EMBO journal.

[13]  J. Kennedy,et al.  Xylans and xylanases: Edited by J. Visser, G. Beldman, M.A. Kusters-van Someren and A.G.J. Voragen, Elsevier, Amsterdam, xiii + 576pp. price US$208.50. ISBN 0-444-89477-21992 , 1995 .

[14]  J. Visser,et al.  aguA, the Gene Encoding an Extracellular α-Glucuronidase from Aspergillus tubingensis, Is Specifically Induced on Xylose and Not on Glucuronic Acid , 1998, Journal of bacteriology.

[15]  M. Penttilä,et al.  Cloning of genes encoding alpha-L-arabinofuranosidase and beta-xylosidase from Trichoderma reesei by expression in Saccharomyces cerevisiae , 1996, Applied and environmental microbiology.

[16]  M. Takano,et al.  Cloning of the xynNB gene encoding xylanase B from Aspergillus niger and its expression in Aspergillus kawachii , 1995 .

[17]  J. Visser,et al.  Isolation of Aspergillus niger creA mutants and effects of the mutations on expression of arabinases and L-arabinose catabolic enzymes. , 1997, Microbiology.

[18]  J. Visser,et al.  Identification, cloning and sequence of the Aspergillus niger areA wide domain regulatory gene controlling nitrogen utilisation. , 1998, Biochimica et biophysica acta.

[19]  J. Visser,et al.  Isolation and analysis of xlnR, encoding a transcriptional activator co‐ordinating xylanolytic expression in Aspergillus niger , 1998, Molecular microbiology.

[20]  Ronald P. de Vries,et al.  The Transcriptional Activator XlnR Regulates Both Xylanolytic and Endoglucanase Gene Expression inAspergillus niger , 1998, Applied and Environmental Microbiology.

[21]  J. Visser,et al.  beta-Xylosidase activity, encoded by xlnD, is essential for complete hydrolysis of xylan by Aspergillus niger but not for induction of the xylanolytic enzyme spectrum. , 1997, European journal of biochemistry.

[22]  J. Visser,et al.  The faeA genes from Aspergillus niger and Aspergillus tubingensis encode ferulic acid esterases involved in degradation of complex cell wall polysaccharides , 1997, Applied and environmental microbiology.

[23]  J. Visser,et al.  Regulation of the xylanase‐encoding xlnA gene of Aspergilius tubigensis , 1994, Molecular microbiology.