G protein-mediated signal transduction: a molecular choreography of G protein activation after GTP binding

A recent report from the Skiniotis group,'published in Nature,provides fascinating insight into the molecular choreography underlying a quintessential cellular signaling mechanism:G protein-mediated signal transduction.Using time-resolved cryo-EM,the authors pieced together many sequential structural snapshots to visualize how a trimeric aβy G protein-after being convinced by its activated G protein-coupled receptor(GPCR)to release GDP-picks up GTP,to set in motion finely tuned conformational transitions that lead to the conversion into the active state and,finally,subunit dissociation as well as disengagement from the receptor.