18 May 2001

The aggregating protein called agrin is a component of two quite different types of synapses: synapses in the neuromuscular junction and the immunological synapse between T cells and antigen-presenting cells. In both systems, membrane proteins cluster in "rafts" at the point of contact, creating a signaling synapse. In the 10 May issue of Science, Adil A. Khan and colleagues show that agrin, a protein required to regulate the formation of these rafts at neuromuscular junctions, also influences raft clustering at the immunological synapse. This may "represent a general mechanism by which functional concentration of signaling molecules is achieved," say the authors.