Phosphorylation-mediated Regulatory Networks in Mycelia of Revealed by Phosphoproteomic Analyses.

Protein phosphorylation is known to regulate pathogenesis, mycelial growth, conidiation and stress response in However, phosphorylation mediated regulatory networks in the fungal pathogen remain largely to be uncovered. In this study, we identified 1621 phosphorylation sites of 799 proteins in mycelia of , including 899 new p-sites of 536 proteins and 47 new p-sites of 31 pathogenicity-related proteins. From the sequences flanking the phosphorylation sites, 19 conserved phosphorylation motifs were identified. Notably, phosphorylation was detected in 7 proteins that function upstream of Pmk1, but not in Pmk1 and its downstream Mst12 and Sfl1 that have been known to regulate appressorium formation and infection hyphal growth of Interestingly, phosphorylation was detected at the site Ser of Pmp1, which is a putative protein phosphatase highly conserved in filamentous fungi but not characterized. We thus generated Δ deletion mutants and dominant allele PMP1 mutants. Phenotyping analyses indicated that Pmp1 is required for virulence, conidiation and mycelial growth. Further, we observed that phosphorylation level of Pmk1 in mycelia was significantly increased in the Δ mutant, but decreased in the PMP1 mutant in comparison with the wild type, demonstrating that Pmp1 phosphorylated at Ser is important for regulating phosphorylation of Pmk1. To our surprise, phosphorylation of Mps1, another MAP kinase required for cell wall integrity and appressorium formation of , was also significantly enhanced in the Δ mutant, but decreased in the PMP1 mutant. In addition, we found that Pmp1 directly interacts with Mps1 and the region AA180-230 of Pmp1 is required for the interaction. In summary, this study sheds new lights on the protein phosphorylation mediated regulatory networks in .