Exploring the bZIP Transcription Factor Regulatory Network in Neurospora Crassa

Microbiology. 2011 Mar;157(Pt 3):747-759. doi: 10.1099/mic.0.045468-0. Epub 2010 Nov 16.

Abstract

Transcription factors (TFs) are key nodes of regulatory networks in eukaryotic organisms, including filamentous fungi such as Neurospora crassa. The 178 predicted DNA-binding TFs in N. crassa are distributed primarily among six gene families, which represent an ancient expansion in filamentous ascomycete genomes; 98 TF genes show detectable expression levels during vegetative growth of N. crassa, including 35 that show a significant difference in expression level between hyphae at the periphery versus hyphae in the interior of a colony. Regulatory networks within a species genome include paralogous TFs and their respective target genes (TF regulon). To investigate TF network evolution in N. crassa, we focused on the basic leucine zipper (bZIP) TF family, which contains nine members. We performed baseline transcriptional profiling during vegetative growth of the wild-type and seven isogenic, viable bZIP deletion mutants. We further characterized the regulatory network of one member of the bZIP family, NCU03905. NCU03905 encodes an Ap1-like protein (NcAp-1), which is involved in resistance to multiple stress responses, including oxidative and heavy metal stress. Relocalization of NcAp-1 from the cytoplasm to the nucleus was associated with exposure to stress. A comparison of the NcAp-1 regulon with Ap1-like regulons in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Candida albicans and Aspergillus fumigatus showed both conservation and divergence. These data indicate how N. crassa responds to stress and provide information on pathway evolution.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Basic-Leucine Zipper Transcription Factors / classification*
  • Basic-Leucine Zipper Transcription Factors / genetics
  • Basic-Leucine Zipper Transcription Factors / metabolism
  • Evolution, Molecular
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Gene Deletion
  • Gene Expression Profiling*
  • Gene Expression Regulation, Fungal*
  • Genes, Fungal
  • Heat-Shock Response
  • Neurospora crassa / genetics
  • Neurospora crassa / growth & development*
  • Neurospora crassa / metabolism
  • Oligonucleotide Array Sequence Analysis / methods
  • Phylogeny
  • Transcription Factor AP-1 / genetics
  • Transcription Factor AP-1 / metabolism

Substances

  • Basic-Leucine Zipper Transcription Factors
  • Fungal Proteins
  • Transcription Factor AP-1