Aspergillus PacC zinc finger transcription factor mediates regulation of both acid- and alkaline-expressed genes by ambient pH

• Published in: The EMBO journal 1995-02, Vol.14 (4), p.779-790
• Main Authors: Tilburn, J, Sarkar, S, Widdick, D.S, Espeso, E.A, Orejas, M, Mungroo, J, Penalva, M.A, Arst, H.N. Jr
• Format: Article
• Language: English
• Subjects: Acid-Base Equilibrium; acidity; alkalinity; Amino Acid Sequence; Aspergillus nidulans; Aspergillus nidulans - genetics; Aspergillus nidulellus; Base Sequence; Binding Sites; Cloning, Molecular; DNA-binding proteins; DNA-Binding Proteins - metabolism; Epistasis, Genetic; Fungal Proteins - genetics; genbank/z47081; gene expression; Gene Expression Regulation, Fungal; genetic regulation; Molecular Sequence Data; mutagenesis; Mutagenesis, Site-Directed; nucleotide sequences; pacc gene; pacc protein; Promoter Regions, Genetic; RNA, Messenger - genetics; Sequence Alignment; Sequence Homology, Amino Acid; structural genes; Structure-Activity Relationship; transcription (genetics); Transcription Factors - physiology; Zinc Fingers
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1995.tb07056.x

The pH regulation of gene expression in Aspergillus nidulans is mediated by pacC, whose 678 residue-derived protein contains three putative Cys2His2 zinc fingers. Ten pacC(c) mutations mimicking growth at alkaline pH remove between 100 and 214 C-terminal residues, including a highly acidic region containing an acidic glutamine repeat. Nine pacC(+/-) mutations mimicking acidic growth conditions remove between 299 and 505 C-terminal residues. Deletion of the entire pacC coding region mimics acidity but leads additionally to poor growth and conidiation. A PacC fusion protein binds DNA with the core consensus GCCARG. At alkaline ambient pH, PacC activates transcription of alkaline-expressed genes (including pacC itself) and represses transcription of acid expressed genes. pacC(c) mutations obviate the need for pH signal transduction.