Cloning and functional characterization of the gene encoding the transcription factor Ace1 in the basidiomycete Phanerochaete chrysosporium.

In this report we describe the isolation and characterization of a gene encoding the transcription factor Ace1 (Activation protein of cup 1 Expression) in the white rot fungus Phanerochaete chrysosporium. Pc-ace1 encodes a predicted protein of 633 amino acids containing the copper-fist DNA binding domain typically found in fungal transcription factors such as Ace1, Mac1 and Haa1 from Saccharomyces cerevisiae. The Pc-ace1 gene is localized in Scaffold 5, between coordinates 220841 and 222983. A S. cerevisiae ace1 null mutant strain unable to grow in high-copper medium was fully complemented by transformation with the cDNA of Pc-ace1. Moreover, Northern blot hybridization studies indicated that Pc-ace1 cDNA restores copper inducibility of the yeast cup 1 gene, which encodes the metal-binding protein metallothionein implicated in copper resistance. To our knowledge, this is first report describing an Ace1 transcription factor in basidiomycetes.