Cell surface receptors

During the past year, the database of ligand-receptor complexes has essenti ally doubled. These new results have immeasurably extended and expanded our view of cell surface receptor structure and function. The flood of data ha s revealed new modes for receptor cross-linking, demonstrating the potentia l stringency of the extracellular requirements for the initiation of intrac ellular signalling and highlighting unexpected interactions suggestive of h igher order clustering.