[Isoform 1]: Deubiquitinating enzyme that may play a role in the ubiquitin-dependent regulation of protein synthesis, downstream of mTORC1 (PubMed:21267069, PubMed:27864334). May associate with the protein synthesis initiation complex and modify its ubiquitination to repress translation (PubMed:27864334). May also repress DNA synthesis and modify different cellular targets thereby regulating cell growth and proliferation (PubMed:27864334). May also play a role in proteasome assembly and function (PubMed:28343629). ; [Isoform 2]: Stimulates protein synthesis. Influences the expression of CCND1/cyclin D1 by promoting its translation and regulates MYC/c-Myc protein stability.