| Title: | The HamE scaffold positively regulates MpkB phosphorylation to promote development and secondary metabolism in Aspergillus nidulans |
| Author(s): | Frawley D; Karahoda B; Sarikaya Bayram O; Bayram O; |
| Address: | "Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland. Biology Department, Maynooth University, Maynooth, Co. Kildare, Ireland. ozgur.bayram@mu.ie. Maynooth University Human Health Research Institute, Kildare, Ireland. ozgur.bayram@mu.ie" |
| DOI: | 10.1038/s41598-018-34895-6 |
| ISSN/ISBN: | 2045-2322 (Electronic) 2045-2322 (Linking) |
| Abstract: | "Mitogen-activated protein kinase (MAPK) pathways are conserved signalling cascades in eukaryotes which regulate a myriad of processes in fungi from sexual reproduction to stress responses. These pathways rely on recruitment of three kinases on a scaffold protein to facilitate efficient kinase phosphorylation and subsequent downstream signalling to the nucleus. The model filamentous fungus Aspergillus nidulans utilises a MAPK pathway termed the pheromone module to regulate both development and secondary metabolism. This complex consists of the MAP3K (SteC), MAP2K (MkkB), MAPK (MpkB) and adaptor protein SteD. To date, there has been no scaffold protein identified for this MAPK pathway. In this study, we characterised a protein termed HamE, which we propose as a scaffold that regulates kinase phosphorylation and signalling in the pheromone module. Mass spectrometry analysis and BIFC experiments revealed that HamE physically interacts with both MkkB and MpkB and transiently interacts with SteC. Deletion of hamE or any of the pheromone module kinases results in reduced sporulation and complete abolishment of cleistothecia production. Mutants also exhibited reductions in expression of secondary metabolite gene clusters, including the velvet complex and sterigmatocystin genes. HamE acts as a positive regulator of MpkB phosphorylation, allowing for HamE to subsequently regulate development and secondary metabolism" |
| Keywords: | "Aspergillus nidulans/*growth & development/metabolism Fungal Proteins/genetics/*metabolism Gene Expression Regulation, Fungal MAP Kinase Signaling System Mass Spectrometry Mitogen-Activated Protein Kinases/*metabolism Mutation Pheromones/metabolism Phosph;" |
| Notes: | "MedlineFrawley, Dean Karahoda, Betim Sarikaya Bayram, Ozlem Bayram, Ozgur eng Research Support, Non-U.S. Gov't England 2018/11/10 Sci Rep. 2018 Nov 8; 8(1):16588. doi: 10.1038/s41598-018-34895-6" |
