Fig. 5
From: Casein kinase 1α has a non-redundant and dominant role within the CK1 family in melanoma progression
CK1α, δ and ε differentially influence beta-catenin and p53/p21 signaling in melanoma cells. a Western blotting of lysates from SbCl2 and SKMEL19 melanoma cells 48 h after overexpression of CK1- isoforms to detect the CK1- substrates β-catenin and p53 with its downstream target p21. b SbCL2 cells and SKMEL19 cells were used in a kinase assay using a peptidic β-catenin substrate (Ser45 phosphor-site) for quantitative determination of Ser45-specific kinase activity of the different isoforms. SKMEL19 cells overexpressing CK1 isoforms and SbCl2 cells transduced with siRNA 48 h before were lysed and subjected to a K-LISA CK1 assay using untreated cell lysates as reference. Biological triplicates were used in case of SKMEL19 samples and quadruplicates in case of SbCL2 cells to calculate the mean with SD (* p < 0.05). c Super8xTOPFlash reporter plasmid was transfected into SKMEL19 cells overexpressing CK1- isoforms and luciferase activity was measured in hexatuplicates for estimation of the TCF/LEF mediated and β-catenin dependent transcriptional activity. Luciferase activity was normalized to cell viability (* p < 0.05; ** p < 0.01)