title: The Aspergillus PacC zinc finger transcription factor mediates regulation of both acid- and alkaline-expressed genes by ambient pH.
abstract: 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 pacCc 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. pacCc mutations obviate the need for pH signal transduction.
authors.affiliation: Department of Infectious Diseases and Bacteriology, Royal Postgraduate Medical School, London, UK.
authors.forename: J
authors.initials: J
authors.lastname: Tilburn
authors.forename: S
authors.initials: S
authors.lastname: Sarkar
authors.forename: D A
authors.initials: DA
authors.lastname: Widdick
authors.forename: E A
authors.initials: EA
authors.lastname: Espeso
authors.forename: M
authors.initials: M
authors.lastname: Orejas
authors.forename: J
authors.initials: J
authors.lastname: Mungroo
authors.forename: M A
authors.initials: MA
authors.lastname: Peñalva
authors.forename: H N
authors.initials: HN
authors.lastname: Arst
mesh_terms: D000136:Acid-Base Equilibrium; D000595:Amino Acid Sequence; D001233:Aspergillus nidulans / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004843:Epistasis, Genetic; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D013329:Structure-Activity Relationship; D014157:Transcription Factors / Q000502:physiology*; D016335:Zinc Fingers
chemical_list: D004268:DNA-Binding Proteins; D005656:Fungal Proteins; C092394:PacC protein, Aspergillus; D012333:RNA, Messenger; D014157:Transcription Factors