USP7 Protein, Human

The USP7 protein, functioning as a hydrolase, plays a pivotal role in deubiquitinating various target proteins, including FOXO4, DEPTOR, KAT5, p53/TP53, MDM2, ERCC6, DNMT1, UHRF1, PTEN, KMT2E/MLL5, and DAXX. Collaborating with DAXX, it prevents MDM2 self-ubiquitination and enhances MDM2's E3 ligase activity toward p53/TP53, promoting p53/TP53 ubiquitination and subsequent degradation. Furthermore, USP7 is involved in cell proliferation during early embryonic development, transcription-coupled nucleotide excision repair (TC-NER) in response to UV damage, and maintenance of DNA methylation. It regulates chromatin structure, exhibits a preference for 'Lys-48'-linked ubiquitin chains, and modulates the circadian clock. Additionally, USP7 contributes to the stabilization of specific proteins involved in gluconeogenesis, neural progenitor cell maintenance, and actin polymerization at endosomal surfaces. Importantly, its diverse functions highlight its significance in cellular processes and response to microbial infections, such as its involvement in the stabilization and trans-activation of the herpesvirus 1 trans-acting transcriptional protein ICP0/VMW110 during HSV-1 infection.