Fig. 4: Analysis of TRIM72 lipid interaction.

a PIP-Strips lipid dot blot analysis revealed that TRIM72 binds phosphatidylserine, phosphatidic acid, phosphatidylinositol (PtdIns), and phosphatidylinositol monophosphates, colored in red. b MST titration results of TRIM72 fragments with phospho-l-serine (PS). Data represent mean ± SEM from n = 3 independent experiments. c Schematic showing the positively charged lysine or arginine residues on the surface of SPRY domain, residues surrounding the cavity are highlighted with orange color. d The electrostatic potential surface of SPRY, positive and negative electrostatic potentials are colored blue and red, respectively. e Representative confocal images of C2C12 myoblasts expressing GFP-TRIM72 mutants (K330A, K460A, K462A, R356A, R371A, and R386A) with or without treatment with H₂O₂/saponin. The nucleus is stained with Hoechst (blue). Scale bar, 10 μm. Micrographs are representative of two independent experiments. f Thermal stabilities of SPRY mutants measured by nano-DSF. Temperatures of the Inflection Point for Ratio F350/F330 are shown; data were from two independent experiments. g The relative 7-AAD positive rate was calculated after cells expressing TRIM72 mutants were treated with H₂O₂/saponin (n = 3, biological replicates). Data have been normalized to TRIM72 WT group; mean ± SEM; *p < 0.05, **p < 0.01; one-way ANOVA with Dunnett΄s multiple comparison test. (K330A: p  = 0.0038; K460A: p  =  0.0201; K462A: p = 0.0064; R356A: p = 0.0069; R371A: p = 0.0055; R386A: p = 0.0310). Source data are provided as a Source Data file.