Integrated proteomic and phosphoproteomic profiling demonstrated that protein kinase MoCK2 modulated mitochondrial energetics, ribosomal biogenesis, and cellular signaling networks in rice blast fungus, Magnaporthe oryzae.

Protein kinase MoCK2 has been identified as a pivotal regulator in the rice blast fungus Magnaporthe oryzae, orchestrating critical biological processes including hyphal growth, conidiation, and host infection. Building upon our previous investigations into its interplay with cellular energy metabolism and polar regeneration during appressorium formation, this study systematically delineated the MoCK2 regulatory network through integrated proteomic and phosphoproteomic analyses. Three key mechanistic insights emerged from this research. Firstly, while MoCK2 deficiency did not directly impair mitochondrial functionality, it disrupted intracellular vesicular trafficking systems, thereby constraining substrate availability for mitochondrial metabolism and ultimately leading to energy homeostasis defects. Secondly, absence of MoCK2 nucleolar localization in regulatory subunit deletion mutants substantially compromised ribosome biogenesis, creating a bottleneck in protein synthesis capacity that failed to meet cellular demands. Thirdly, phosphoregulation analysis demonstrated MoCK2's multifaceted role as a signaling node, modulating critical developmental transitions through phosphorylation-dependent control of conidial germination, appressorial morphogenesis, and host penetration apparatus assembly. These findings established MoCK2 as a central coordinator linking organelle dynamics, translational regulation, and infection-related signaling cascades. This study provides a conceptual framework for future investigations into the functional characterization of MoCK2, while also offering methodological references for CK2 research across diverse biological systems.