CreA-mediated repression in Aspergillus nidulans does not require transcriptional auto-regulation, regulated intracellular localisation or degradation of CreA.
The major regulatory protein in carbon repression in Aspergillus nidulans is CreA. Strains constitutively over-expressing creA show normal responses to carbon repression, indicating that auto-regulation of creA is not essential for CreA-mediated regulation. In these strains, high levels of CreA are present whether cells are grown in repressing or derepressing conditions, indicating large-scale degradation of CreA does not play a key role. CreA is located in the nucleus and cytoplasm in cells when grown in either repressing or derepressing conditions, and absence of CreB, CreD or AcrB does not affect either the localisation or amount of CreA. Therefore, CreA must require some modification or interaction to act as a repressor. Deletion analysis indicates that a region of CreA thought to be important for repression in Trichoderma reesei and Sclerotina sclerotiorum CreA homologues is not critical for function in Aspergillus nidulans.
Roy
Preeti
P
School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, Australia.
Lockington
Robin A
RA
Kelly
Joan M
JM
D001203:Ascomycota / Q000235:genetics; D001233:Aspergillus nidulans / Q000502:physiology*; D015153:Blotting, Western; D002244:Carbon / Q000378:metabolism; D002467:Cell Nucleus / Q000737:chemistry; D003593:Cytoplasm / Q000737:chemistry; D004252:DNA Mutational Analysis; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015966:Gene Expression Regulation, Fungal; D017930:Genes, Reporter; D049452:Green Fluorescent Proteins / Q000032:analysis / Q000235:genetics; D008856:Microscopy, Fluorescence; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000032:analysis / Q000235:genetics; D012097:Repressor Proteins / Q000378:metabolism*; D014242:Trichoderma / Q000235:genetics
D005656:Fungal Proteins; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; C071237:CreA protein, Aspergillus nidulans; D049452:Green Fluorescent Proteins; D002244:Carbon