%0 Journal Article %J Trends in cell biology %D 2010 %T Evaluating Smoothened as a G-protein-coupled receptor for Hedgehog signalling. %A Ayers, Katie L %A Thérond, Pascal P %K Animals %K Drosophila Proteins %K Hedgehog Proteins %K Humans %K Models, Biological %K Phosphorylation %K Protein Binding %K Receptors, G-Protein-Coupled %K Signal Transduction %N 5 %P 287-98 %R 10.1016/j.tcb.2010.02.002 %V 20 %X The Hedgehog signalling pathway controls numerous developmental processes. In response to Hedgehog, Smoothened (Smo), a seven-pass transmembrane protein, orchestrates pathway signalling and controls transcription factor activation. In the absence of Hedgehog, the receptor Patched indirectly inhibits Smo in a catalytic manner. Many questions surrounding Smo activation and signalling remain. Recent findings in Drosophila and vertebrate systems have provided strong evidence that Smo acts as a G-protein-coupled receptor. We discuss the role and regulation of Smo and reassess similarities between Smo and G-protein-coupled receptors. We also examine recently identified members of the invertebrate and vertebrate Smo signalling cascades that are typical components of G-protein-coupled receptor pathways. Greater understanding of the mechanisms of Smo activation and its signalling pathways will allow implementation of novel strategies to target disorders related to disruption of Hh signalling. %8 2010 May