The role of the VosA-repressed dnjA gene in development and metabolism in Aspergillus species.
The DnaJ family of proteins (or J-proteins) are molecular chaperones that govern protein folding, degradation, and translocation in many organisms. Although J-proteins play key roles in eukaryotic and prokaryotic biology, the role of J-proteins in Aspergillus species is currently unknown. In this study, we characterized the dnjA gene, which encodes a putative DnaJ protein, in two Aspergillus species: Aspergillus nidulans and Aspergillus flavus. Expression of the dnjA gene is inhibited by the velvet regulator VosA, which plays a pivotal role in spore survival and metabolism in Aspergillus. The deletion of dnjA decreased the number of asexual spores (conidia), produced abnormal conidiophores, and reduced sexual fruiting bodies (cleistothecia) or sclerotia. In addition, the absence of dnjA caused increased sterigmatocystin or aflatoxin production in A. nidulans and A. flavus, respectively. These results suggest that DnjA plays a conserved role in asexual and sexual development and mycotoxin production in Aspergillus species. However, DnjA also plays a species-specific role; AniDnjA but not AflDnjA, affects conidial viability, trehalose contents, and thermal tolerance of conidia. In plant virulence assay, the infection ability of the ΔAfldnjA mutant decreased in the kernels, suggesting that DnjA plays a crucial role in the pathogenicity of A. flavus. Taken together, these results demonstrate that DnjA is multifunctional in Aspergillus species; it is involved in diverse biological processes, including fungal differentiation and secondary metabolism.
['Son|Ye-Eun|YE|', 'Cho|He-Jin|HJ|', 'Chen|Wanping|W|', 'Son|Sung-Hun|SH|', 'Lee|Mi-Kyung|MK|', 'Yu|Jae-Hyuk|JH|', 'Park|Hee-Soo|HS|http://orcid.org/0000-0003-4303-9418']
D001231:Aspergillus flavus D001233:Aspergillus nidulans D005656:Fungal Proteins D015966:Gene Expression Regulation, Fungal D010935:Plant Diseases D013045:Species Specificity D013172:Spores, Fungal D000071436:Thermotolerance D014199:Trehalose D014908:Triticum
Aspergillus nidulans Aspergillus flavus Aflatoxins Asexual development DnaJ domain