Smoothened (SMO) is a cell surface receptor that, with Patched, mediates hedgehog signaling to regulate gene expression through the Gli transcription factors. GSA 10 is a quinolinecarboxamide derivative that acts as an agonist of SMO. By acting at SMO, GSA 10 has been shown to promote the differentiation of multipotent mesenchymal progenitor cells into osteoblasts (EC50 = 1.2 μM). Most notably, GSA 10 does not recognize the classic cyclopamine binding site as do other SMO agonists and as such has been used to characterize a novel SMO active site.
