The endocytic cargo adaptor complex is required for cell-wall integrity via interacting with the sensor FgWsc2B in Fusarium graminearum

Palmitoyl Transferase FonPAT2-Catalyzed Palmitoylation of the FonAP-2 Complex Is Essential for Growth, Development, Stress Response, and Virulence in Fusarium oxysporum f. sp. niveum

“…The ABE/LC-MS assay identified a total of 211 putative palmitoylated proteins that were present in the WT but absent in ΔFonpat2 in 2 independent biological replicates, and 36 palmitoylated proteins overlapped in the two replicates (Table S1). Some of the putative palmitoylated proteins were previously reported to be involved in the pathogenicity of filamentous fungi such as F. graminearum , Botrytis cinerea , Verticillium dahliae , and Aspergillus flavus , for example, FOXG_00780 (AP-2 complex subunit α) and FOXG_04448 (AP-2 complex subunit μ) ( 41 , 42 ), FOXG_05141 (autophagy-related ATG7) and FOXG_01866 (ATG20) ( 56 – 58 ), FOXG_11305 (myosin-1) ( 59 ), FOXG_19023 (chitin synthase) ( 60 ), FOXG_13911 (Ras-like protein Rab-11B), and FOXG_03575 (Ras-like C3 botulinum toxin substrate 1) ( 61 ), and FOXG_11168 (ankyrin repeat protein NUC-2) ( 62 ). Meanwhile, homologues for some of the putative palmitoylated proteins were previously shown to be palmitoylated in yeast and other organisms, for example, FOXG_08214 (synaptobrevin-like YKT6) ( 63 ), FOXG_04579 (actin γ) ( 33 ), FOXG_13911 (Ras-like protein Rab-11B), FOXG_03575 (Ras-like C3 botulinum toxin substrate 1) ( 64 ), and FOXG_00122 (Ca 2+ transporting ATPase) ( 33 ).…”

“…The comparative proteomics study identified a total of 211 putative FonPAT2-palmitoylated substrate proteins, and some have homologs that are known to be palmitoylated in other fungal species; e.g., homologs of FOXG_04579 (actin γ) and FOXG_00122 (Ca 2+ -transporting ATPase) were previously reported to be palmitoylated in A. nidulans ( 33 ). Importantly, several the FonPAT2-palmitoylated substrates have homologues that have been shown to function in pathogenicity of fungi, e.g., the AP-2 complex subunits (FOXG_00780 and FOXG_04448) and autophagy-related proteins (FOXG_05141 and FOXG_01866) ( 41 , 42 , 51 – 53 ). This implies the general significance of protein palmitoylation in regulating the virulence of plant-pathogenic fungi, which is consistent with the finding that a single PAT, CnPfa4, is responsible for the palmitoylation of a subset of proteins that are critical in the pathogenicity of C. neoformans ( 30 ).…”

“…Like the function of the FgAP-2 complex in F. graminearum ( 41 , 42 ), the FonAP-2 complex is essential for vegetative growth and hyphal morphology, conidiation and conidial morphology, cell wall integrity, and virulence in Fon . In particularly, disruption of each of the FonAP-2 complex subunits resulted in defects in hyphal polarized growth and cell wall stress response, which is in agreement with the observations that the AP-2 complex is involved in regulating cell wall integrity in F. graminearum and yeast ( 40 , 42 ).…”

“…In Aspergillus , the AP-2 complex plays a specialized clathrin-independent role in apical endocytosis and polar growth through interacting with endocytic markers and membrane lipid flippases ( 40 ). In the wheat scab fungus Fusarium graminearum , the AP-2 complex was found to be required for hyphal polarized growth, polar localization of FgDnfA and FgDnfB, and full virulence ( 41 ), and the subunit FgAP-2μ was involved in cell wall integrity via interacting with FgWsc2B ( 42 ).…”

Regulation of biotic interactions and responses to abiotic stresses by MAP kinase pathways in plant pathogenic fungi

“…In S. cerevisiae, cell stressors, such as CR and Caspofungin, are sensed by the Mid2 and Wsc1 sensors (Jin et al 2013). Similar sensors appear to be involved in sensing these cell wall stressors in fungal pathogens, such as U. maydis and F. graminearum (Carbó and Pérez-Martín 2010;Xu et al 2019). In yeast, cell wall damage caused by β-1,3-glucanase and protease activities is sensed by Sho1 and mucin Hkr1 (not Msb2) to activate Hog1, which in turn activates Slt2 (Rodríguez-Peña et al 2013).…”