Reconstitution of XXXX coupling to calcium mobilization via genetic complementation.

@entity16350 @entity2426 @entity12711 @entity535 @entity19 @entity1199 @entity3783 @entity12710 @entity141 @entity669
The integrity of the T cell receptor complex (CD3-TCR) transduction machinery is central to T cell development and to T cell effector function. Molecular dissection of the multimeric CD3-TCR complex revealed that at least two associated polypeptides, @entity12711 and @entity12710 , autonomously couple antigenic recognition event to early and late events of the intracytoplasmic activation cascade. A 18- @entity535 motif based on a tandem YXXL stretch, the @entity16350 ( @entity16350 ) motif, is necessary and sufficient to the transducing properties of both @entity12711 and @entity12710 . Stimulation of chimeric molecules made of ecto- and transmembrane domains of various cell surface proteins and intracytoplasmic domains of @entity12710 or @entity12711 leads to an increase in the intracellular @entity141 concentration ([ @entity141 ]i) in Jurkat cells. We describe here that a similar @entity3783 /zeta chimeric molecule was unable to induce a detectable [ @entity141 ]i rise upon @entity3783 cross-linking once expressed in the @entity19 thymoma BW-. A @entity141 influx could, however, be triggered in BW- cells by @entity2426 , i.e. following depletion of @entity141 stores. Somatic cell hybrids made from BW- and either thymocytes or mature lymph node T cells reconstituted the coupling of @entity12711 to the @entity141 signal via an @entity16350 motif-dependent pathway. However, pervanadate-induced @entity141 mobilization, a phenomenon attributed to @entity669 phosphorylation, was impaired in BW-cells and reconstituted in hybridomas. In contrast to the @entity141 response, @entity1199 production was induced in both BW- and hybrids cells, which questions the functional relevance of [ @entity141 ]i augmentation in T cell activation. In conclusion, the properties of the BW- thymoma, which define a novel group of @entity12711 transduction cell mutants, as well as its complementation by somatic cell fusion demonstrate that this cell line represents a useful model to dissect the signaling pathway that couples @entity12711 to @entity141 mobilization by genetic reconstitution.
