The wide-domain carbon catabolite repressor CreA indirectly controls expression of the Aspergillus nidulans xlnB gene, encoding the acidic endo-beta-(1,4)-xylanase X(24).
The Aspergillus nidulans xlnB gene, which encodes the acidic endo-beta-(1,4)-xylanase X(24), is expressed when xylose is present as the sole carbon source and repressed in the presence of glucose. That the mutation creA(d)30 results in considerably elevated levels of xlnB mRNA indicates a role for the wide-domain repressor CreA in the repression of xlnB promoter (xlnBp) activity. Functional analyses of xlnBp::goxC reporter constructs show that none of the four CreA consensus target sites identified in xlnBp are functional in vivo. The CreA repressor is thus likely to exert carbon catabolite repression via an indirect mechanism rather than to influence xlnB expression by acting directly on xlnB.
Orejas
M
M
Departamento de Biotecnología, Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, 46100 Burjassot, Valencia, Spain. morejas@iata.csic.es
MacCabe
A P
AP
Pérez-González
J A
JA
Kumar
S
S
Ramón
D
D
D001233:Aspergillus nidulans / Q000201:enzymology* / Q000235:genetics; D043364:Endo-1,4-beta Xylanases; D004794:Enzyme Repression; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D017354:Point Mutation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D014994:Xylose / Q000378:metabolism; D014995:Xylosidases / Q000235:genetics* / Q000378:metabolism*
D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans; D014994:Xylose; D014995:Xylosidases; D043364:Endo-1,4-beta Xylanases; D005947:Glucose