E3 ubiquitin-protein ligase which catalyzes the formation of 'Lys-48'-polyubiquitin chains (PubMed:20059950, PubMed:30696809). Mediates the ubiquitination and subsequent degradation of phosphorylated Akt (AKT1, AKT2 and AKT3) in the nucleus (PubMed:20059950). Acts as a terminal regulator of Akt signaling after activation; its phosphorylation by Akt, which is a prerequisite for ubiquitin ligase activity, suggests the existence of a regulation mechanism required to control Akt levels after activation (PubMed:20059950). Positively regulates TGFB1-induced epithelial- mesenchymal transition and myofibroblast differentiation by mediating the ubiquitination and subsequent degradation of SMURF2 (PubMed:30696809). Regulates neuronal differentiation by regulating actin remodeling and Golgi organization via a signaling cascade involving RHOA, CIT and ROCK (PubMed:17488780, PubMed:24695496). Inhibits cell proliferation (PubMed:30203323). {ECO:0000269|PubMed:17488780, ECO:0000269|PubMed:20059950, ECO:0000269|PubMed:24695496, ECO:0000269|PubMed:30203323, ECO:0000269|PubMed:30696809}. This is the function of TTC3 (tetratricopeptide repeat domain 3, Ensembl gene identifier ENSG00000182670).