Fig. 3: PSPC1 modulates Wnt signaling and Wnt3a autocrine function. | Nature Communications

Fig. 3: PSPC1 modulates Wnt signaling and Wnt3a autocrine function.

From: PSPC1-interchanged interactions with PTK6 and β-catenin synergize oncogenic subcellular translocations and tumor progression

Fig. 3: PSPC1 modulates Wnt signaling and Wnt3a autocrine function.

a HGF (10 ng/ml) treatment of Huh-7 cells as an EMT induction model upregulates PSPC1 and facilitates reciprocal subcellular translocations of p-PTK6 and β-catenin. The expression of Sp1, α-tubulin and Na+/K+-ATPase, markers of nuclear, cytosolic and membrane localization, respectively. b Under HGF stimulation, nuclear PSPC1 interacted with β-catenin and not PTK6 owing to increased cytosolic and membrane active PTK6 expression shown by IP/Western blotting analysis. Arrows indicate proteins after IB. Arrowheads are the IgG heavy chain. c Expression of PSPC1-Y523F mutant in SK-hep1 cells decreased nuclear p-PTK6 sequestration to facilitate cytoplasmic and membrane p-PTK6 translocation and facilitate nuclear translocation of β-catenin demonstrated by Western blotting analysis. d, e Expression of PSPC1-Y523F mutant reduced the p-PTK6 nuclear sequestration and enhanced PSPC1-Y523F interaction with nuclear β-catenin demonstrated by IP/Western blotting analysis in SK-hep1 cells. f Relative transcriptional activity of TOP-Flash and FOP-Flash with TCF4/LEF1 luciferase reporter assays in 293T cells cotransfected with mock control, PSPC1, Wnt3a, β-catenin del-N (deletion of N-terminus), PSPC1 shRNA (shPSPC1)/β-catenin del-N, and PSPC1/TCF4-DN (dominant negative). Data represent the mean ± SEM (n = 3). g Relative transcriptional activation of TCF4/LEF1 luciferase promoter reporter assays with TOP-Flash or FOP-Flash expressing SK-hep1 cells transfected with vector alone (Mock), PSPC1, PSPC1/PTK6, PSPC1-Y523F and PSPC1-Y523F/PTK6 constructs. Data represent the mean ± SEM (n = 3). h Secreted cytokines Wnt1 and Wnt3a measured by ELISA assays in the concentrated conditioned medium of SK-hep1 cells transfected with different PSPC1/PTK6 expression constructs. Data represent the mean ± SEM (n = 3). All data statistics were based on *p < 0.05, **p < 0.01, and ***p < 0.001 calculated by one-way ANOVA with Brown–Forsythe test. Source data are provided as a Source Data file.

Back to article page