Synonyms:Deubiquitinating enzyme 1, hUBP, ubiquitin specific peptidase 1, Ubiquitin thiolesterase 1, UBP, USP1 Background:Negative regulator of DNA damage repair which specifically deubiquitinates monoubiquitinated FANCD2(PubMed:15694335). Also involved in PCNA-mediated translesion synthesis(TLS) by deubiquitinating monoubiquitinated PCNA(PubMed:16531995). Has almost no deubiquitinating activity by itself and requires the interaction with WDR48 to have a high activity(PubMed:18082604, PubMed:26388029).