The function of RNF19A (ring finger protein 19A, RBR E3 ubiquitin protein ligase, Ensembl gene identifier ENSG00000034677) is as follows. E3 ubiquitin-protein ligase which accepts ubiquitin from E2 ubiquitin-conjugating enzymes UBE2L3 and UBE2L6 in the form of a thioester and then directly transfers the ubiquitin to targeted substrates, such as SNCAIP or CASR. Specifically ubiquitinates pathogenic SOD1 variants, which leads to their proteasomal degradation and to neuronal protection. {ECO:0000269|PubMed:11237715, ECO:0000269|PubMed:12145308, ECO:0000269|PubMed:12750386, ECO:0000269|PubMed:15456787, ECO:0000269|PubMed:16513638}.