USP7

USP7

USP7, also known as Ubiquitin Specific Peptidase 7, is a deubiquitinating enzyme that plays a crucial role in various cellular processes. It is encoded by the USP7 gene and is highly conserved across different species, including humans.

Structure and Function

USP7 consists of several functional domains, including a catalytic domain responsible for its deubiquitinating activity. This enzyme is primarily localized in the nucleus, although it can also be found in the cytoplasm. It interacts with numerous proteins and substrates, allowing it to regulate various cellular pathways.

One of the key functions of USP7 is its involvement in the regulation of the ubiquitin-proteasome system (UPS). The UPS is responsible for the degradation of proteins that are marked with ubiquitin tags. USP7 acts as a deubiquitinase, removing ubiquitin molecules from target proteins and preventing their degradation. This process helps in maintaining protein stability and controlling cellular processes such as DNA repair, cell cycle progression, and apoptosis.

Role in Cancer

USP7 has been implicated in the development and progression of various types of cancer. It interacts with several oncogenes and tumor suppressor proteins, modulating their stability and activity. For example, USP7 stabilizes the tumor suppressor protein p53 by removing its ubiquitin tags, preventing its degradation. This leads to the activation of p53-mediated cell cycle arrest and apoptosis, which are important mechanisms for preventing tumor formation.

Additionally, USP7 has been found to interact with several viral proteins, including those from human papillomavirus (HPV) and Epstein-Barr virus (EBV). These interactions play a role in viral replication and pathogenesis, highlighting the importance of USP7 in viral infections.

Clinical Significance

Given its involvement in cancer and viral infections, USP7 has emerged as a potential therapeutic target. Inhibitors of USP7 have been developed and tested in preclinical studies, showing promising results in suppressing tumor growth and enhancing the efficacy of chemotherapy. However, further research is needed to fully understand the complex regulatory mechanisms of USP7 and its potential as a therapeutic target.

References

1. Nicholson B, Suresh Kumar KG. The multifaceted roles of USP7: new therapeutic opportunities. Cell Biochem Biophys. 2011;60(1-2):61-68. doi:10.1007/s12013-011-9164-2

2. Colland F. The therapeutic potential of deubiquitinating enzyme inhibitors. Biochem Soc Trans. 2010;38(1):137-143. doi:10.1042/BST0380137

See Also

• Ubiquitin
• Proteasome
• p53
• Ubiquitin-proteasome system
• Cancer
• Viral infections