CD38 Signaling in T Cells Is Initiated within a Subset of Membrane Rafts Containing Lck and the CD3-ζ Subunit of the T Cell Antigen Receptor

摘要: In this study we present data supporting that most CD38 is pre-assembled in a subset of Brij 98-resistant raft vesicles, which were stable at 37 °C, and have relatively high levels Lck the CD3-ζ subunit T cell antigen receptor-CD3 complex contrast with 98-soluble pool, where associated CD3-ζ, not detected. Our further indicate following engagement, LAT are tyrosinephosphorylated exclusively rafts, some key signaling components translocate into rafts (i.e. Sos p85-phosphatidylinositol 3-kinase). Moreover, N-Ras results activated within immediately upon ligation, whereas Erk was mainly found soluble fractions delayed kinetics respective to Ras activation. Furthermore, full phosphorylation CD3-ϵ only occurs partial tyrosine correlated increased c-Cbl non-raft fractions. Taken together, these suggest that, unlike able initiate propagate several activating pathways, possibly by facilitating critical associations other subsets, for example, via its capacity interact CD3-ζ. Overall, findings provide first evidence operates two functionally distinct microdomains plasma membrane.