The impact of bZIP Atf1ortholog global regulators in fungi

Abstract

Regulation of signal transduction pathways is crucial for the maintenance of cellular homeostasis and organismal development in fungi. Transcription factors are key elements of this regulatory network. The basic-region leucine zipper (bZIP) domain of the bZIP-type transcription factors is responsible for DNA binding while their leucine zipper structural motifs are suitable for dimerization with each other facilitiating the formation of homodimeric or heterodimeric bZIP proteins. This review highlights recent knowledge on the function of fungal orthologs of the Schizosaccharomyces pombe Atf1, Aspergillus nidulans AtfA, and Fusarium verticillioides FvAtfA, bZIP-type transcription factors with a special focus on pathogenic species. We demonstrate that fungal Atf1-AtfA-FvAtfA orthologs play an important role in vegetative growth, sexual and asexual development, stress response, secondary metabolite production, and virulence both in human pathogens, including Aspergillus fumigatus, Mucor circinelloides, Penicillium marneffei, and Cryptococcus neoformans and plant pathogens, like Fusarium ssp., Magnaporthe oryzae, Claviceps purpurea, Botrytis cinerea, and Verticillium dahliae. KEY POINTS: • Atf1 orthologs play crucial role in the growth and development of fungi. • Atf1 orthologs orchestrate environmental stress response of fungi. • Secondary metabolite production and virulence are coordinated by Atf1 orthologs.

Keywords: Development; Environmental stress regulatory network; Secondary metabolism; Vegetative growth; Virulence; bZIP-type transcription factor.

Fig. 1

Atf1-AtfA-FvAtfA orthologs are involved in the maintenance of vegetative gowth as well as in asexual and sexual developments of fungi. Schematic vegetative, asexual, and sexual morphological forms of fungi with successful functional characterization of Atf1-AtfA-FvAtfA orthologs are presented

Fig. 2

Atf1-AtfA-FvAtfA orthologs coordinate environmental stress response of fungi. Typical morphological forms of fungi and major stress responses governed by Atf1-AtfA-FvAtfA orthologs are presented