Signaling by Committee: Receptor Clusters Determine Pathways of Cellular Activation

ABSTRACT Receptor clustering is a common signaling mechanism for cell surface receptors. Exogenous ligands such as antibodies or syn-thetic analogues can be used to artificially in-duce clustering. New studies using defined synthetic ligands suggest that the spatial organi-zation of these clusters attenuates signaling in one pathway but has no effect in another. T he components of the cell mem-brane serve many roles. Far from be-ing a static barrier between cellular contents and the extracellular environment, the proteins and lipids of the membrane shuttle both molecules and information be-tween these compartments. Though many integral membrane proteins that bind to ex-tracellular components are well studied, ke