crnA encodes a nitrate transporter in Aspergillus nidulans

S E Unkles, K L Hawker, C Grieve, E I Campbell, P Montague, J R Kinghorn

Research output: Contribution to journalArticlepeer-review

184 Citations (Scopus)


The nucleotide sequence of the Aspergillus nidulans crnA gene for the transport of the anion nitrate has been determined. The crnA gene specifies a predicted polypeptide of 483 amino acids (molecular weight 51,769). A hydropathy plot suggests that this polypeptide has 10 membrane-spanning helices with an extensive hydrophilic region between helices six and seven. No striking homology was observed between the crnA protein and other reported membrane proteins of either prokaryotic or eukaryotic organisms, indicating that the crnA transporter may represent another class of membrane protein. Northern blotting results with wild-type cells show that (i) control of crnA expression is subject to nitrate (and nitrite) induction as well as nitrogen metabolite repression and (ii) regulation of the crnA gene is exerted at the level of mRNA accumulation, most likely at transcription, in response to the nitrogen source in the growth medium. Furthermore, similar studies with mutants of nirA and areA control genes and the niaD nitrate reductase structural gene show that crnA expression is mediated by the products of nirA (nitrate induction control gene), areA (nitrogen metabolite repression control gene), and niaD (involved in autoregulation of nitrate reductase).
Original languageEnglish
Pages (from-to)204-8
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number1
Publication statusPublished - 1 Jan 1991


  • Amino Acid Sequence
  • Anion Transport Proteins
  • Aspergillus nidulans
  • Base Sequence
  • Carrier Proteins
  • Cloning, Molecular
  • DNA, Fungal
  • Escherichia coli
  • Fungal Proteins
  • Genes, Fungal
  • Models, Structural
  • Molecular Sequence Data
  • Mutation
  • Nitrates
  • Phenotype
  • Plasmids
  • Protein Conformation
  • Restriction Mapping
  • Sequence Homology, Nucleic Acid
  • Transcription, Genetic


Dive into the research topics of 'crnA encodes a nitrate transporter in Aspergillus nidulans'. Together they form a unique fingerprint.

Cite this