Many fungal genes contain CCAAT sequence in their promoter regions. We have found CCAAT-binding proteins in A. nidulans: AnCF for amdS encoding the A. nidulans acetamidase, AnCP for taa encoding A. oryzae Taka-amylase A, and PENRI for the aatA and bidirectionally oriented genes acvA and ipnA, encoding the A. nidulans penicillin biosynthetic enzymes. AnCF/AnCP/PENRl has been shown to contain a polypeptide encoded by the hapCgene, a homologue of the HAP3 gene of S. cerevisiae. Recently, two A. nidulans genes, hapB and hapE, encoding polypeptides with a central core showing high similarity to Hap2p and Hap5p have been isolated. HapB, HapC and HapE were shown to be necessary and sufficient for DNA binding by reconstitution of the complex in vitro. In this study, A. oryzae was found to contain a nuclear protein designated AoCP, which bound to the CCAAT sequence in the promoter region of the taa gene. AoCP contained a component immunologically similar to A. nidulans HAPC. A homologue of the A. nidulans hapC gene was isolated from A. oryzae, designated as AohapC and sequenced. The AohapC gene introduced into an A. nidulans hapC deletion strain was found to complement the hapC deletion and resulted in restoration of the CCAAT binding activity, leading to enhancement of taa gene expression. Furthermore, two genes, AohapB and AohapE, homologues of A. nidulans hapB and hapE were isolated from A. oryzae. We succeeded in reconstituting the CCAAT-binding complex from purified recombinant polypeptides, AoHapB, AoHapC and AoHapE.
Fungal Genet. Newsl. 46 (Supl):
Full conference title:
Fungal Genetics Conference 20th
- Fungal Genetics Conference 20th (1999)