SplA/Ryanodine Receptor Domain And SOCS Box Containing Protein 3 (SPSB3)

By database analysis, Wang et al. (2005) identified SPSB3, which they called SSB3. The deduced 348-amino acid protein shares 16% amino acid identity with SPSB1 and has a long N-terminal extension. SPSB3 contains a central SPRY domain and a C-terminal SOCS box. Coimmunoprecipitation studies showed that SPSB3 interacted with MET. The International Radiation Hybrid Mapping Consortium mapped the SPSB3 gene to chromosome 16.However, siRNA knockdown of SPSB1 repressed HGF-induced reporter gene expression and also suppressed Elk1 activation. Mutation analysis showed that SPSB1 was phosphorylated at tyr31 upon HGF stimulation, and tyr31-phosphorylated SPSB1 interacted with p120-RASGAP (RASA1) specifically in response to HGF stimulation.