Fig. 3.

Potentiation of Wnt/β-catenin signaling by LGR4 and LGR5 in response to RPSO1–4. HEK293T cells were transiently transfected with LGR4, LGR5, or vector, plus the β-catenin reporter plasmid Super 8× TOPFlash (firefly luciferase) and pRL-SV40 (renilla luciferase) and then stimulated with serial dilutions of purified recombinant RSPO1 (A), RSPO2 (B), RSPO3 (C), or RSPO4 (D) in the presence of Wnt3a conditioned media (CM). Firefly luciferase activity of each well was normalized to that of renilla luciferase activity of the same well. All error bars are SEM (n = 4).