The Aspergillus niger GCN4 homologue, cpcA, is transcriptionally regulated and encodes an unusual leucine zipper

Mol Microbiol. 1997 Jan;23(1):23-33. doi: 10.1046/j.1365-2958.1997.1741549.x.

Abstract

The general control transcriptional regulator gene cpcA of Aspergillus niger was cloned by complementation of a Saccharomyces cerevisiae delta gcn4 mutant strain. The encoded protein conferred resistance to amino acid analogues when expressed in yeast. Disruption of cpcA in A. niger resulted in a strain which is sensitive towards 3-aminotriazole and fails to respond to amino acid starvation, cpcA encodes a transcript of approximately 2400 nucleotides in length that includes a 5' leader region of 900 nucleotides. The 5' leader region contains two small open reading frames, suggesting translational control of gene expression. Steady-state mRNA levels of cpcA increase by a factor of three upon amino acid starvation. The coding region of cpcA is interrupted by a 57 bp intron and the deduced amino acid sequence displays an approximately 30% overall identity to yeast GCN4p and Neurospora crassa cpc1p. Critical amino acid residues of the transcriptional activation domains of GCN4p are conserved in cpcAp. The basic DNA-binding domain shows up to 70% amino acid sequence identity to other basic zipper (bZIP)-type transcriptional activators. cpcAp binds specifically to a GCN4p recognition element in gel retardation experiments. The C-terminal dimerization domain encodes a leucine zipper with only a single leucine residue.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amitrole / pharmacology
  • Aspergillus niger / genetics*
  • Aspergillus niger / metabolism
  • Base Sequence
  • Basic-Leucine Zipper Transcription Factors
  • Chromosomes, Fungal
  • DNA, Fungal
  • DNA-Binding Proteins / genetics*
  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Fungal
  • Leucine
  • Leucine Zippers / genetics*
  • Molecular Sequence Data
  • Protein Kinases / genetics
  • RNA, Messenger
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae Proteins*
  • Sequence Homology, Amino Acid
  • Transcription Factors / genetics*
  • Transcription, Genetic*

Substances

  • Basic-Leucine Zipper Transcription Factors
  • CPCA protein, Aspergillus niger
  • DNA, Fungal
  • DNA-Binding Proteins
  • Fungal Proteins
  • RNA, Messenger
  • Saccharomyces cerevisiae Proteins
  • Transcription Factors
  • Protein Kinases
  • Leucine
  • Amitrole

Associated data

  • GENBANK/X99215