Has E3 ubiquitin-protein ligase activity (PubMed:24130170). Acts as an anti-apoptotic regulator of the JNK pathway by ubiquitinating and promoting the degradation of SH3RF1, a scaffold protein that is required for pro-apoptotic JNK activation (PubMed:22128169). Facilitates TNF-mediated recruitment of adapter proteins TRADD and RIPK1 to TNFRSF1A and regulates PAK4 protein stability via inhibition of its ubiquitin-mediated proteasomal degradation (PubMed:24130170). Inhibits PPP1CA phosphatase activity (PubMed:19389623, PubMed:19945436). {ECO:0000269|PubMed:19389623, ECO:0000269|PubMed:19945436, ECO:0000269|PubMed:22128169, ECO:0000269|PubMed:24130170}. This is the function of SH3RF2 (SH3 domain containing ring finger 2, Ensembl gene identifier ENSG00000156463).