Functional Characterization Of CAAX Proteases Moste24 And Morce1 In Magnaporthe Oryzae

The rice blast fungus Magnaporthe oryzae is a kind of filamentous ascomycete fungus,which propagates through the form of conidium.Recently,the pathogen has become one of the most serious pathogens affecting the yield of rice around the world.Therefore,deploying the control strategies of rice blast by using molecular biology and genetics methods has become urgently required for the efficiency of cereal cultivation.Post-translational prenylation pathway(CAAX modification)can mediate subcellular localization of critical proteins including small GTPases,laminins,and protein-protein interaction in eukaryotes.Here,we examined two CAAX prenyl proteases MoSte24 and MoRce1 to characterize whether the prenyl modification plays a significant role in different development stages in M.oryzae.Moreover,we also preliminarily established the relationship between prenyl protease and its modified substrate,the results are summarized as following.We first screened the fungal database and then obtained two prenyl proteases MoSte24 and MoRce1 in M.oryzae.According to the results of protein domain prediction,both of proteins exhibit multiple transmembrane domains,indicating that they are integral membrane proteins.The Realtime Quantitative PCR assays showed that MoSTE24 was dramatically upregulated in infection stage when compared to the mycelia stage.While the expression level of MoRCE1 in different development stages did not show significantly changes.The subcellular localization experiment proved that MoSte24 was found to localize to the endoplasmic reticulum,while MoRce1 may localize at the plasma membrane.Further phenotypic analysis of MoSTE24 and MoRCE1 showed that deletion of MoRCE1 exhibited growth defects under the cell wall stress conditions.And deletion of MoSTE24 caused a significant defect in invasive hyphae stage.Furthermore,the localization of MoRho3 was changed in ?Moste24 compared with wild type Guy11.MoRho3 was primarily located in the plasma membrane in Guy11,while it was mainly distributed in the cytoplasm in ?Moste24.Therefore,we supposed that MoRho3 may be one of the substrates modified by MoSte24.Taken together,the prenyl proteases MoSte24 and MoRce1 have different cellular localization and may have functional differentiation in M.oryzae.MoRce1 modifies the cell wall synthesis-related proteins,while MoSte24 is high expressed in the early stage of infection and may indirectly regulate the pathogenicity of M.oryzae by modifying some pathogenic related proteins like MoRho3.