Reconstitution of interactions between tyrosine kinases and the high affinity IgE receptor which are controlled by receptor clustering.

摘要: High affinity IgE receptor (Fc epsilon RI) signaling after contact with antigen occurs in response to clustering. This paper describes methodology, based on vaccinia virus driven protein expression, for probing pathways and its application Fc RI interactions the lyn syk tyrosine kinases. Reconstitution of complete tetrameric receptor, a non-hematopoietic 'null' cell line is sufficient reconstruct clustering-controlled phosphorylation activation syk, without apparent requirement hematopoietic specific phosphatases. The src family kinase phosphorylates clustering, resulting binding phosphorylated RI. Lyn also participates manner which dependent Using overexpression active dominant negative proteins mast naturally expresses RI, we corroborate syk's role downstream phosphorylation, demonstrate that SH2 domains protect ITAMs from ongoing dephosphorylation. Based these results, propose clustering controls lyn-mediated by shifting balance between dephosphorylation towards accumulation functions bring into microenvironment where it becomes activated, thereby allowing indirectly control activity.