Fig. 4: Alcohol-induced MATα1 phosphorylation at Ser114 is required for PIN1 binding.

a IP analysis of human normal and AH liver lysates, pair-fed and ethanol-fed mouse livers, and AML-12 cells treated with ethanol using anti-phosphoserine antibody followed by western blot analysis against MATα1 (n = 3 independent samples/experiments, p = 0.001 for AH vs normal; p = 0.021 ethanol-fed vs pair-fed; and p = 0.008 ethanol vs control AML-12). b Phos-Tag gels of phosphorylated MATα1 in cytosolic and mitochondrial fractions of AML-12 cells treated with ethanol. Unphosphorylated and phosphorylated recombinant human MATα1 protein is shown as a control (left). c Area under the curve of the phosphorylated peptide which corresponds to MATα1 Ser114 and its unmodified counterpart in WT mouse liver. d Quantitation of the MATα1 Ser114 in normal (n = 4) and AH (n = 5) human livers (p = 0.03). The center line, bounds of box, and whiskers represent mean, 25th to 75th percentile range, and minimum to maximum range. Normal liver is shown in blue and AH in red. e IP analysis of AML-12 and f HepG2 overexpressing MATα1 WT or S114A cell lysates using anti-His-Tag antibody followed by western blot analysis against PIN1. *p < 0.05. Statistical significance was determined by using two-tailed, one-sample t-test for treatment comparisons and ANOVA test for group comparisons. Results are shown as mean ± SEM. Source data are provided as a Source data file. AH alcoholic hepatitis, EV empty vector, IP immunoprecipitation, pSer phosphor-serine, WT wild type.