| Title: | "The tetrameric pheromone module SteC-MkkB-MpkB-SteD regulates asexual sporulation, sclerotia formation and aflatoxin production in Aspergillus flavus" |
| Author(s): | Frawley D; Greco C; Oakley B; Alhussain MM; Fleming AB; Keller NP; Bayram O; |
| Address: | "Department of Biology, Maynooth University, Maynooth, Co. Kildare, Ireland. Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin, USA. Department of Molecular Biosciences, University of Kansas, Lawrence, Kansas, USA. Department of Microbiology, School of Genetics and Microbiology, Moyne Institute of Preventive Medicine, Trinity College Dublin, Dublin, Ireland. Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, USA" |
| ISSN/ISBN: | 1462-5822 (Electronic) 1462-5814 (Print) 1462-5814 (Linking) |
| Abstract: | "For eukaryotes like fungi to regulate biological responses to environmental stimuli, various signalling cascades are utilized, like the highly conserved mitogen-activated protein kinase (MAPK) pathways. In the model fungus Aspergillus nidulans, a MAPK pathway known as the pheromone module regulates development and the production of secondary metabolites (SMs). This pathway consists five proteins, the three kinases SteC, MkkB and MpkB, the adaptor SteD and the scaffold HamE. In this study, homologs of these five pheromone module proteins have been identified in the plant and human pathogenic fungus Aspergillus flavus. We have shown that a tetrameric complex consisting of the three kinases and the SteD adaptor is assembled in this species. It was observed that this complex assembles in the cytoplasm and that MpkB translocates into the nucleus. Deletion of steC, mkkB, mpkB or steD results in abolishment of both asexual sporulation and sclerotia production. This complex is required for the positive regulation of aflatoxin production and negative regulation of various SMs, including leporin B and cyclopiazonic acid (CPA), likely via MpkB interactions in the nucleus. These data highlight the conservation of the pheromone module in Aspergillus species, signifying the importance of this pathway in regulating fungal development and secondary metabolism" |
| Keywords: | "Aflatoxin B1 Aflatoxins/*metabolism Aspergillus flavus/genetics/*growth & development/*metabolism Aspergillus nidulans Fungal Proteins/genetics/*metabolism Gene Expression Regulation, Fungal Mitogen-Activated Protein Kinases/genetics/metabolism Phenotype;" |
| Notes: | "MedlineFrawley, Dean Greco, Claudio Oakley, Berl Alhussain, Mohamed M Fleming, Alastair B Keller, Nancy P Bayram, Ozgur eng R01 GM112739/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't India 2020/02/19 Cell Microbiol. 2020 Jun; 22(6):e13192. doi: 10.1111/cmi.13192. Epub 2020 Mar 3" |
