Patent ID: 8541192

Claim:
An in vitro, biochemical method of identifying an inhibitor of ubiquitin specific protease 1(USP1) comprising: (i) contacting an isolated USP1 with a test compound in the presence of monoubiquitinated proliferating cell nuclear antigen (PCNA) or ubiquitin-7-amido-4-methylcoumarin, wherein said USP1 is selected from the group consisting of SEQ ID NO: 3 or the polypeptide set forth by amino acids 17-785 of SEQ ID NO: 3, and wherein said PCNA comprises SEQ ID NO: 2; and (ii) detecting the deubiquitination of said PCNA or ubiquitin-7-amido-4-methylcoumarin using an antibody or fluorescence, wherein a decrease in the deubiquitination of said PCNA or ubiquitin-7-amido-4-methylcoumarin in the presence of the test compound, relative to the absence of the test compound, identifies said test compound as an inhibitor of USP1.