The casein kinase MoYck1 regulates development, autophagy, and virulence in the rice blast fungus

Abstract

Casein kinases are serine/threonine protein kinases that are evolutionarily conserved in yeast and humans and are involved in a range of important cellular processes. However, the biological functions of casein kinases in the fungus Magnaporthe oryzae, the causal agent of destructive rice blast disease, are not characterized. Here, two casein kinases, MoYCK1 and MoHRR25, were identified and targeted for replacement, but only MoYCK1 was further characterized due to the possible nonviability of the MoHRR25 deletion mutant. Disruption of MoYCK1 caused pleiotropic defects in growth, conidiation, conidial germination, and appressorium formation and penetration, therefore resulting in reduced virulence in rice seedlings and barley leaves. Notably, the MoYCK1 deletion triggered quick lipidation of MoAtg8 and degradation of the autophagic marker protein GFP-MoAtg8 under nitrogen starvation conditions, in contrast to the wild type, indicating that autophagy activity was negatively regulated by MoYck1. Furthermore, we found that HOPS (homotypic fusion and vacuolar protein sorting) subunit MoVps41, a putative substrate of MoYck1, was co-located with MoAtg8 and positively required for the degradation of MoAtg8-PE and GFP-MoAtg8. In addition, MoYCK1 is also involved in the response to ionic hyperosmotic and heavy metal cation stresses. Taken together, our results revealed crucial roles of the casein kinase MoYck1 in regulating development, autophagy and virulence in M. oryzae.

Stage-Specific Genetic Interaction between FgYCK1 and FgBNI4 during Vegetative Growth and Conidiation in Fusarium graminearum

“…Although Hrr25 is not essential for cell viability in budding yeast, the deletion of HRR25 orthologues is lethal in some fungi including A . nidulans , F. graminearum , Magnaporthe oryzae [ 7 , 21 , 22 ]. Yeast Yck1 and Yck2 are involved in regulating cellular morphogenesis, cytokinesis, nutrient sensing, septin assembly, and endocytosis [ 23 , 24 ].…”

“…In the rice blast fungus M. orzyzae , the Moyck1 deletion mutant is viable but defective in vegetative growth, appressorium formation, and plant infection. MoYCK1 also regulates autophagy and responses to ionic hyperosmotic and heavy metal cation stresses [ 22 ].…”

“…Limited studies in N. crassa , M. oryzae , and F. graminearum have shown that the YCK1 /2 orthologs are important for hyphal growth in filamentous fungi but their exact function is not clear [ 7 , 8 , 22 , 28 ]. In this study, we further determined the function of FgYck1 in polarized growth and cell wall integrity in F. graminearum and isolated and characterized spontaneous suppressors of the Fgyck1 mutant.…”

The Plant Homeodomain Protein Clp1 Regulates Fungal Development, Virulence, and Autophagy Homeostasis in Magnaporthe oryzae

“…Knockdown of PHF23 promoted autophagosome synthesis ( 60 ). Both enhanced and attenuated autophagy resulted in impaired virulence of M. oryzae ( 16 , 20 , 75 – 77 ). Therefore, we speculate that Clp1 affects the development and pathogenicity of M. oryzae in two ways: one is to regulate autophagy homeostasis by interacting with autophagy-related proteins at PAS and autophagosomes, and the other is to regulate gene transcription in the nucleus.…”

The Expression of microRNA in Adult Rat Heart with Isoproterenol-Induced Cardiac Hypertrophy

“…The MAPK signaling pathway, FoXO signaling pathway, and Wnt signaling pathway are conserved in mammals and play important biological functions. MAPKs are serine/threonine protein kinases that mediate the response of a cell to a variety of extracellular stimuli [45]. The FoxO signaling pathway is involved in cell proliferation [46], and Wnt pathways are involved in the control of gene expression, cell behavior, cell adhesion, and cell polarity [47].…”