Velvet domain protein VosA represses the zinc cluster transcription factor SclB regulatory network for Aspergillus nidulans asexual development, oxidative stress response and secondary metabolism

PLoS Genet. 2018 Jul 25;14(7):e1007511. doi: 10.1371/journal.pgen.1007511. eCollection 2018 Jul.

Abstract

The NF-κB-like velvet domain protein VosA (viability of spores) binds to more than 1,500 promoter sequences in the filamentous fungus Aspergillus nidulans. VosA inhibits premature induction of the developmental activator gene brlA, which promotes asexual spore formation in response to environmental cues as light. VosA represses a novel genetic network controlled by the sclB gene. SclB function is antagonistic to VosA, because it induces the expression of early activator genes of asexual differentiation as flbC and flbD as well as brlA. The SclB controlled network promotes asexual development and spore viability, but is independent of the fungal light control. SclB interactions with the RcoA transcriptional repressor subunit suggest additional inhibitory functions on transcription. SclB links asexual spore formation to the synthesis of secondary metabolites including emericellamides, austinol as well as dehydroaustinol and activates the oxidative stress response of the fungus. The fungal VosA-SclB regulatory system of transcription includes a VosA control of the sclB promoter, common and opposite VosA and SclB control functions of fungal development and several additional regulatory genes. The relationship between VosA and SclB illustrates the presence of a convoluted surveillance apparatus of transcriptional control, which is required for accurate fungal development and the linkage to the appropriate secondary metabolism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspergillus nidulans / physiology*
  • Fungal Proteins / genetics*
  • Fungal Proteins / metabolism
  • Gene Expression Regulation, Fungal / physiology
  • Gene Regulatory Networks / physiology
  • Genes, Fungal / genetics
  • Oxidative Stress / genetics*
  • Promoter Regions, Genetic / genetics
  • Protein Domains / physiology
  • Reproduction, Asexual / genetics*
  • Secondary Metabolism / genetics*
  • Spores, Fungal / genetics
  • Spores, Fungal / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism
  • Zinc Fingers / physiology

Substances

  • Fungal Proteins
  • Transcription Factors

Grants and funding

This paper was supported by the following grants: Deutsche Forschungsgemeinschaft (DFG): BR 1502/11-2 and SFB860. HBB acknowledges the Deutsche Forschungsgemeinschaft for funding of the Impact II qTof mass spectrometer (INST 161/810-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.