two's company

Pairing up is sometimes paramount to life. On the molecular scale, dimerization in our bodies is at the heart of many fundamental biological processes, such as the transduction of signals from the outside of a cell to the inside for instance. Split two molecules apart and, just like taking the propeller away from a ship, things are sure to change drastically. Signal transduction, on which life depends, is hugely due to protein-protein interaction. A ligand recognises its receptor, binds to it, thereby triggering off biological processes downstream. In the case of Kit ligand, and its receptor Kit, their binding is subject to the dimerization of both the ligand and its receptor, following which signals are transduced further downstream triggering off other biological processes. Kit ligand and Kit are a case of substantial conformational change on the molecular level – dimerization but also angles which bring about flexibility – that are necessary for Kit to get on with its job.