The Variable Hinge Region of Novel PKCs Determines Localization to Distinct Regions of the Immunological Synapse

摘要: The immunological synapse (IS) formed between a T cell and its cognate antigen-presenting (APC) enables the directional secretion of cytolytic inflammatory molecules. Synaptic architecture is established in part by two-step cascade novel protein kinase C (nPKC) isozymes. PKCe PKCη arrive at IS first, occupy entire synaptic membrane. Then, PKCθ accumulates smaller zone center contact. We investigated molecular basis for this differential recruitment behavior using chimeric nPKC constructs total internal reflection fluorescence microscopy. Our studies revealed that V3 linker just N-terminal to domain plays crucial role specifying localization. Substitution switched scope kinetics accumulation PKCη, vice versa. Although was necessary compartmentalization, it not sufficient, as tandem C1 domains were also required mediate membrane association. Together, these results suggest model whereby controls sub-compartmentalization after initial domain-mediated IS.