Roles in dimerization and blue light photoresponse of the PAS and LOV domains of Neurospora crassa white collar proteins

Mol Microbiol. 1998 Aug;29(3):719-29. doi: 10.1046/j.1365-2958.1998.00955.x.


The genes coding for white collar-1 and white collar-2 (wc-1 and wc-2) have been isolated previously, and their products characterized as Zn-finger transcription factors involved in the control of blue light-induced genes. Here, we show that the PAS dimerization domains present in both proteins enable the WC-1 and WC-2 proteins to dimerize in vitro. Homodimers and heterodimers are formed between the white collar (WC) proteins. A computer analysis of WC-1 reveals a second domain, called LOV, also identified in NPH1, a putative blue light photoreceptor in plants and conserved in redox-sensitive proteins and in the phytochromes. The WC-1 LOV domain does not dimerize with canonical PAS domains, but it is able to self-dimerize. The isolation of three blind wc-1 strains, each with a single amino acid substitution only in the LOV domain, reveals that this region is essential for blue light responses in Neurospora. The demonstration that the WC-1 proteins in these LOV mutants are still able to self-dimerize suggests that this domain plays an additional role, essential in blue light signal transduction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Dimerization
  • Fungal Proteins*
  • Light
  • Molecular Sequence Data
  • Mutation
  • Neurospora crassa / genetics
  • Neurospora crassa / physiology*
  • Phenotype
  • Transcription Factors / genetics
  • Transcription Factors / physiology*


  • DNA-Binding Proteins
  • Fungal Proteins
  • Transcription Factors
  • wc-1 protein, Neurospora crassa
  • white collar 2 protein, Neurospora

Associated data