Journal: Redox Biology
Article Title: Src-mediated PHB2 phosphorylation disrupts mitochondrial cristae through cardiolipin dissociation in hepatocellular carcinoma
doi: 10.1016/j.redox.2026.104073
Figure Lengend Snippet: Src-mediated phosphorylation disrupts PHB1/2 complex stability and triggers PHB2 cytoplasmic mislocalization. A Electrostatic surface potential analysis of PHB2 showing the effect of phosphorylation. Left panel: wild-type PHB2 with Y34 and Y77 residues. Right panel: phosphorylated PHB2 (phos-Y34 and phos-Y77) showing altered electrostatic distribution. Blue indicates positive charge (+5), white is neutral (0), and red indicates negative charge (−5). The double-framed line represents the inner mitochondria membrane. B Effect of Src-mediated phosphorylation on PHB1/2 complex formation. Blue Native PAGE (BN-PAGE) analysis of PHB2-WT and phosphorylation-resistant mutant PHB2–Y34F/Y77F Flag in HepG2 cells with or without SRC overexpression. Protein load was verified by Coomassie blue (CBB) staining. Lower panel shows SDS-PAGE verification of SRC, PHB1, PHB2, and β-Actin expression. C Analysis of PHB1/2 complex formation in LO2 versus HepG2 cell lines. Upper panel: representative BN-PAGE showing PHB1/2-SC (supercomplex) and PHB1/2 complex formation detected with PHB2 and AFG3L2 antibodies. Lower panel: SDS-PAGE Western blot analysis of PHB2, AFG3L2, and β-Actin (loading control) expression levels. D Effect of OXPHOS inhibitors on PHB1/2 complex formation. Left panels: representative BN-PAGE analysis of PHB1/2-SC and PHB1/2 complexes in control and treated conditions (H 2 O 2 , Rotenone, Antimycin, Oligomycin (OLG), and combined Antimycin/Oligomycin (OA)). Protein load was verified by Coomassie blue (CBB) staining. Lower panel: representative Western blot showing protein expression levels of PHB2, AFG3L2, TIM23, and β-Actin (loading control). E Subcellular distribution of PHB2 under tumor microenvironment stresses. Western blot analysis of PHB2 in mitochondrial and cytoplasmic fractions of HepG2 cells treated with H 2 O 2 (oxidative stress), CoCl 2 (hypoxia mimetic), rotenone (Complex I inhibitor), or antimycin (Complex III inhibitor). F Dose-dependent PHB2 redistribution in response to increasing SRC expression levels. Western blot analysis showing PHB2 subcellular localization in mitochondrial and cytoplasmic fractions after SRC overexpression in HepG2 cells. HSP60 serves as mitochondrial marker and β-Actin as cytoplasmic marker (E, F). All Blue Native PAGE and Western blot experiments (B–F) were performed in at least three independent experiments. Representative images are shown.
Article Snippet: The following antibodies were used: anti -PHB2 (1:1000, Cell Signaling Technology #14085), anti -PHB1 (1:1000, Abcam ab75771), anti -phosphotyrosine (1:1000, Cell Signaling Technology #9411), anti -SRC (1:1000, Cell Signaling Technology #2109), anti -β-actin (1:5000, Sigma-Aldrich A5441), anti -HSP60 (1:1000, Cell Signaling Technology #12165), anti -OMA1 (1:1000, Santa Cruz Biotechnology sc-515788), anti -OPA1 (1:1000, BD Biosciences 612606), anti -VDAC (1:2000, Proteintech #66345‐1‐Ig), and anti -AFG3L2 (1:1000, Abcam ab139503).
Techniques: Phospho-proteomics, Membrane, Blue Native PAGE, Mutagenesis, Over Expression, Staining, SDS Page, Expressing, Western Blot, Control, Marker