USP1

USP1 ubiquitin-specific protease 1 is a deubiquitinating enzyme that plays a key role in various biological processes. It consists of 785 amino acid residues and has a catalytic domain consisting of an N-terminal cysteine box and two C-terminal histidine boxes, of which Cys90, His593, and Asp751 constitute the catalytic core. USP1 also contains three additional inserts L1, L2, and L3, which have important effects on its activity. The main functions of USP1 include participating in DNA damage response DDR, regulating proteins in the Fanconi anemia FA pathway and translesion DNA synthesis TLS pathway, and controlling DNA repair processes. In addition, USP1 is also involved in immune regulation, autophagy, and cell differentiation. In terms of signaling pathways, USP1 restores key events in the FA pathway by deubiquitinating FANCD2Ub-FANCIUb, and maintains genomic stability by regulating the ubiquitination status of PCNA. USP1 is closely related to the occurrence and progression of tumors, and its abnormal expression has been found in various tumors, making it a promising therapeutic target. Inhibiting USP1 may help solve the problem of resistance to cisplatin and PARP inhibitors, providing new ideas for cancer treatment.