Prion protein is a component of the multimolecular signaling complex involved in T cell activation

In this study we analyzed the interaction of prion protein PrPC with components of glycosphingolipid-enriched microdomains in lymphoblastoid T cells. PrPC was distributed in small clusters on the plasma membrane, as revealed by immunoelectron microscopy. PrPC is present in microdomains, since it coimmunoprecipitates with GM3 and the raft marker GM1. A strict association between PrPC and Fyn was revealed by scanning confocal microscopy and coimmunoprecipitation experiments. The phosphorylation protein ZAP-70 was immuno-precipitated by anti-PrP after T cell activation. These results demonstrate that PrPC interacts with ZAP-70, suggesting that PrPC is a component of the multimolecular signaling complex within microdomains involved in T cell activation. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.