Fig. 3: Mapping of SSSCA1 and TNKS1 binding.
From: Sjögren syndrome/scleroderma autoantigen 1 is a direct Tankyrase binding partner in cancer cells
a Schematic representation of His-GFP-tagged SSSCA1 constructs. FL full length. b Different constructs of human SSSCA1 were expressed in HeLa cells. After TAP, the binding of each construct to endogenous TNKS1 was assessed by western blotting. Green stars indicate the constructs of interest. β-actin was chosen for input control because of the very low and barely detectable endogenous expression of TNKS1. c Schematic representation of His-GFP-tagged TNKS1 constructs. FL full length. d Different constructs of human TNKS1 were expressed in HeLa cells. After TAP, the binding of each construct to endogenous SSSCA1 was assessed by western blotting. Green stars indicate the constructs of interest. e TNKS1 ARC1–3 was expressed and purified from E. coli. Schematic representation of the construct and Coomassie stained SDS-gel control after purification. f TNKS1 ARC1–3 binding to FAM-tagged peptides (positive control Axin1 in black, negative control Axin1 G>R in gray, SSSCA1-H1 in pink, and SSSCA1-H2 in purple) was assessed by fluorescence polarization. Affinities of each peptide for TNKS1 ARC1–3 are indicated. n = 4; error bars, SEM; Kd error values, standard error of the fit; n.q. not quantifiable.
