BioEssays 9∕2015

Rotate and activate . On pages 959–967 , Ichiro Maruyama proposes a “rotation model” for the activation of transmembrane cell‐surface receptors. Following this model, receptors exist in a dimeric form prior to ligand binding. The extracellular domain (ECD) has a rotationally flexible structure while the intracellular domain (ICD) is relatively stable. Ligand binding stabilizes the flexible ECD and induces conformational changes of the domains. This in turn induces or allows a rotation of the transmembrane domains leading to a rearrangement of the ICD, hence making the ICD flexible for activation of/interaction with cytoplasmic proteins.