Isolation of Aspergillus niger creA mutants and effects of the mutations on expression of arabinases and L-arabinose catabolic enzymes.
Aspergillus niger mutants relieved of carbon repression were isolated from an areA parental strain by selection of colonies that exhibited improved growth on a combination of 4-aminobutanoic acid (GABA) and D-glucose. In addition to derepression of the utilization of GABA as a nitrogen source in the presence of D-glucose, three of the four mutants also showed derepression of L-alanine and L-proline utilization. Transformation of the mutants with the A. niger creA gene, encoding the repressor protein CREA, re-established the areA phenotype on GABA/D-glucose, identifying the mutations as creAd. The creA gene mapped on chromosome IV by linkage analysis and contour-clamped homogeneous electric field hybridization. The creA mutants obtained were used to study the involvement of CREA in repression by D-glucose of arabinases and L-arabinose catabolism in A. niger. In wild-type A. niger, alpha-L-arabinofuranosidase A, alpha-L-arabinofuranosidase B, endo-arabinase, L-arabinose reductase and L-arabitol dehydrogenase were induced on L-arabinose, but addition of D-glucose prevented this induction. Repression was relieved to varying degrees in the creA mutants, showing that biosynthesis of arabinases and L-arabinose catabolic enzymes is under control of CREA.
Ruijter
George J G
GJG
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands.
Vanhanen
Sipo A
SA
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands.
Gielkens
Marco M C
MMC
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands.
van de Vondervoort
Peter J I
PJI
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands.
Visser
Jaap
J
Section Molecular Genetics of Industrial Microorganisms, Wageningen Agricultural University, Dreijenlaan 2, 6703 HA Wageningen, The Netherlands.
D001089:Arabinose / Q000378:metabolism; D001234:Aspergillus niger / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D002874:Chromosome Mapping; D005656:Fungal Proteins / Q000235:genetics*; D015870:Gene Expression; D005800:Genes, Fungal; D005947:Glucose / Q000378:metabolism; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D009154:Mutation; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics*; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D005656:Fungal Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans; D005680:gamma-Aminobutyric Acid; D001089:Arabinose; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase; C082526:arabinan endo-1,5-alpha-L-arabinosidase; D005947:Glucose