| Interaction of fibroblast growth factor receptor 3 and the adapter protein SH 2 B . ^^^ We identified the adapter protein SH 2 B as an FGFR 3 interacting protein . ^^^ Coimmunoprecipitation experiments demonstrate binding of the SH 2 B beta isoform to FGFR 3 in 293T cells . ^^^ Tyrosine phosphorylation of SH 2 B beta was observed when coexpressed with activated FGFR 3 mutants such as the weakly activated mutant N540K or the strongly activated mutant K650E , both associated with human developmental syndromes . ^^^ The extent of tyrosine phosphorylation of SH 2 B beta correlates with receptor activation , suggesting that FGFR 3 activation mediates tyrosine phosphorylation of SH 2 B beta . ^^^ |