Abstract
Upon stimulation of the T cell receptor, proteins involved in proximal T cell signaling gather in lipid rafts to guide external stimuli to the intracellular compartment through the formation of signaling complexes. The rearrangement of lipid rafts upon engagement of the T cell receptor is crucial to ensure a rapid and efficient signal transduction. To assess lipid raft protein composition, we here provide a qualitative mass spectrometric characterization of the Detergent- Resistant Membrane (DRM) proteome in human primary T cells, identifying a total of 425 proteins. Furthermore, we have addressed proteins solely associated with DRMs in resting T cells and proteins solely observed in DRMs upon engagement of the T cell receptor. Only a small group of proteins were found to be exclusively located to DRMs under either of these conditions, indicating that the protein composition of DRMs instimulated cells versus resting cells is remarkably stable. Classification of the 425 proteins identified in DRMs into functional categories revealed a particularly high occurrence of cytoskeletal proteins, indicating that DRMs remain attached to the underlying cortical actin cytoskeleton upon activation of T cells.
© 2013 Moltu K, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.