IMM250H1 Chapter Notes -Lck, Tyrosine, Integrin
Document Summary
When a t cell meets an antigen presenting cell You need lots of tcrs engaging mhcs to get a signal need smac composed of Tcrs and co-receptors to clustered on one side of the cell stimulated by antigen recognition. Integrins surrounding the tcr + co-receptor zone: they bind the apc complement integrins to seal the two cells together. Present on cytoplasmic tail of many cell surface receptors that pass signals. 2 tyrosines (y) separated by 9 12 aas. Y x x [l/v] x6 9 y x x [l/v] x = any aa, l = leucine, v = valine. Recognized by another kinase family with sh2 (src homology 2) domains: resting t cell itams not phos. Fyn bound to cytoplasmic domain of cd3. Has 2 sh2 domains ( can bind 2 itams) Threshold # of activated zap-70s needed for downstream events. This is actually a cluster of 100-1000 receptors polarized on one side of cell.
