SplA/Ryanodine Receptor Domain And SOCS Box Containing Protein 4 (SPSB4)

By database analysis, Wang et al. (2005) identified SPSB4, which they called SSB4. The deduced 273-amino acid protein shares 75% amino acid identity with SPSB1. SPSB4 contains a central SPRY domain and a C-terminal SOCS box. Coimmunoprecipitation studies showed that SPSB4 interacted with MET . The International Radiation Hybrid Mapping Consortium mapped the SPSB4 gene to chromosome 3 .

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.