A chimeric protein having deubiquitinase activity, methods of identifying anti-deubiquitinase compounds using chimeric proteins, and kits comprising chimeric proteins are described herein. In one aspect, a chimeric protein comprises a mammalian deubiquitinase catalytic domain, a linker domain, and a non-human deubiquitinase proteasome binding domain. In another aspect, a method of identifying a compound having deubiquitinase inhibition activity comprises a) providing an assay for identifying a compound having deubiquitinase inhibition activity, wherein the assay comprises one or more biological cells comprising a chimeric protein comprising a mammalian deubiquitinase catalytic domain, a linker domain, and a non-human deubiquitinase proteasome binding domain; b) screening the assay with at least one compound; and c) identifying a compound having deubiquitinase inhibition activity based on survival of the biological cell. In another aspect, a kit comprises a biological cell comprising a herein disclosed chimeric protein.