The regulatory subunit MoB56 of PP2A phosphatase regulates pathogenicity, growth and development in a protein complex with the atypical catalytic subunit Ppg1 in the rice blast fungus Magnaporthe oryzae

Abstract Protein phosphatase 2A (PP2A) is usually a heterotrimeric enzyme, consisting of catalytic subunit (C) and scaffolding (A) associated with third, variable regulatory (B). Fungi carry single gene for A C subunits, three genes the B subunit. In addition, fungi contain conserved atypical named Ppg1, which essential to pathogenicity rice blast fungus Magnaporthe oryzae . However, it remains largely unknown how combinatorically assembles subunits or Ppg1 regulate fungal growth, development pathogenicity. Here we report functionally characterize one PP2A, MoB56, in M. We generated MoB56 deletion mutant Δmob56 , was severely defective vegetative conidiation septum formation, had lost The defects could be rescued by introducing fused GFP ( MoB56-GFP ) at its terminus. Fluorescence microscopic observations revealed that signals were widely distributed cytoplasm formed dot-like structure center conidia, appressoria infection hyphae, supporting function septation. Further, performed co-immunoprecipitation pull-down assays, indicating forms protein complex mycelial cells. yeast two-hybrid assay showed interact PP2A but not while subunit, suggesting ties formation. has multiple isoforms, are likely originated from alternative splicing sumoylation. This first revealing B56 PP2A-like fungi. Importantly, this study B56, like offering potential new lead control devastating pathogen targeting specific phosphatase. Together, provides important information understanding regulates disease.