Clustering of a lipid-raft associated pool of ERM proteins at the immunological synapse upon T cell receptor or CD28 ligation

Although ezrin is tyrosine phosphorylated following TCR ligation, its biological role in T cell activation is not known. Here, we show that ezrin clusters at the immunological synapse upon T cell stimulation. Clustering of ezrin can be triggered by TCR ligation, or, more efficiently, by CD28 ligation. The clusters of ezrin at the immunological synapse include serine/threonine phosphorylated ezrin predominantly located within cell membrane lipid rafts. Based on these data, we propose that ezrin may play a role in the formation/stabilization of lipid raft signalosomes at the immunological synapse and therefore contribute to sustain TCR-dependent signalling. (C) 2002 Elsevier Science B.V. All rights reserved.