GPCR introduction

G-protein-coupled receptors, or GPCRs, are the common mode of receptor singling via GTP binding proteins and thus play a key role in the mediation of a wide variety of different physiological signals. The polypeptide chain that makes up GPCRs passes through the plasma membrane of the cell seven times and can also be called 7-tm receptors. Due to their importance in the signaling of changes in the concentration of hormones, lipids, neurotransmitters, photons and more, determining the mechanism for G-protein-coupled receptors and how it is able to discriminate and regulate these signals were questions of paramount importance to medicine and molecular biology.