HACA, the transcriptional activator of the unfolded protein response (UPR) in Aspergillus niger, binds to partly palindromic UPR elements of the consensus sequence 5'-CAN(G/A)NTGT/GCCT-3'.
The promoters of UPR target genes contain an unfolded protein response element (UPRE), which confers the stress inducibility to the gene, via an interaction with the transcription activator HACA. In the promoters of the Aspergillus ER-stress responsive genes bipA, cypB, pdiA, prpA, tigA, and hacA, a consensus sequence was identified, which was located close to the transcription start site of the gene (<81 bp), and corresponds to the sequence CAN(G/A)NTGT/GCCT. The UPRE is a partly palindromic sequence around a dispensable spacer nucleotide, followed by four highly conserved bases. By an in vitro selection procedure, an optimal binding site for HACA was isolated. This sequence, ACACGTGTCCT, resembles the UPRE but lacks the spacer nucleotide. It has a much higher binding affinity than the identified UPREs, and in vivo it behaves as a more powerful cis-acting element.
Mulder
Harm J
HJ
Danisco Innovation Copenhagen, Langebrogade 1, DK 1001 Copenhagen, Denmark. harm.mulder@danisco.com
Nikolaev
Igor
I
Madrid
Susan M
SM
D001234:Aspergillus niger / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence / Q000235:genetics*; D004252:DNA Mutational Analysis; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D004721:Endoplasmic Reticulum / Q000502:physiology; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D016350:Leucine Zippers / Q000235:genetics; D018832:Molecular Chaperones / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000235:genetics; D020218:Response Elements / Q000235:genetics*; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D024363:Transcription Initiation Site
D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D018832:Molecular Chaperones; D015534:Trans-Activators