Enables thiol-dependent deubiquitinase and transcription coactivator activity. Involved in histone deubiquitination and positive regulation of transcription, DNA-templated. Predicted to be located in cytosol; nucleoplasm; and plasma membrane. Predicted to be active in cytoplasm. Is expressed in left lung; right lung; and submandibular gland primordium. Orthologous to human USP21 (ubiquitin specific peptidase 21). [provided by Alliance of Genome Resources, Apr 2022]