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.