Yin Z, Zhang X, Wang J, Yang L, Feng W, Chen C, Gao C, Zhang H, Zheng X, Wang P, Zhang Z.

Environ Microbiol. 2018 May 4. doi: 10.1111/1462-2920.14102. [Epub ahead of print]

Abstract

The rice blast fungus Magnaporthe oryzae has eight regulators of G-protein signaling (RGS) and RGS-like proteins (MoRgs1 to MoRgs8) that exhibit both distinct and shared regulatory functions in the growth, differentiation, and pathogenicity of the fungus. We found MoRgs7 with a unique RGS-seven transmembrane (7-TM) domain motif is localized to the highly dynamic tubule-vesicular compartments during early appressorium differentiation followed by gradually degradation. To explore whether this involves an active signal perception of MoRgs7, we identified a Gbeta-like/RACK1 protein homolog in M. oryzae MoMip11 that interacts with MoRgs7. Interestingly, MoMip11 selectively interacted with several components of the cAMP regulatory pathway, including Gα MoMagA and the high-affinity phosphodiesterase MoPdeH. We further showed that MoMip11 promotes MoMagA activation and suppresses MoPdeH activity thereby up-regulating intracellular cAMP levels. Moreover, MoMip11 is required for the response to multiple stresses, a role also shared by Gbeta-like/RACK1 adaptor proteins. In summary, we revealed a unique mechanism by which MoMip11 links MoRgs7 and G-proteins to reugulate cAMP signaling, stress responses, and pathogenicity of M. oryzae. Our studies revealed the multitude of regulatory networks that govern growth, development, and pathogenicity in this important causal agent of rice blast. This article is protected by copyright. All rights reserved.

See https://www.ncbi.nlm.nih.gov/pubmed/29727050