N4BP1 Gene - NEDD4 Binding Protein 1 | Function, Mutations & Disease

N4BP1 (NEDD4 Binding Protein 1) is a protein-coding gene that encodes a member of the NEDD4-binding protein family. The protein contains a C-terminal NYN domain with ribonuclease activity and interacts with NEDD4 family E3 ubiquitin ligases. N4BP1 functions as a negative regulator of antiviral immune responses by degrading viral RNA and modulating ubiquitin-dependent signaling pathways. It is involved in the regulation of cytokine production, apoptosis, and cellular stress responses. The gene is expressed in multiple tissues and is implicated in various cancers and inflammatory conditions.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• Ubiquitin mediated proteolysis (KEGG: hsa04120)

• RIG-I-like receptor signaling pathway (KEGG: hsa04622)

• Antiviral mechanism by IFN-stimulated genes (Reactome: R-HSA-1169410)

N4BP1 is a 597-amino acid protein with a molecular weight of approximately 67 kDa. It contains an N-terminal NYN domain (Pfam: PF14436) that exhibits ribonuclease activity, and a C-terminal region that binds NEDD4 family E3 ubiquitin ligases. The protein localizes to the cytoplasm and nucleus. Through its RNase activity, N4BP1 degrades viral RNA, thereby restricting replication of viruses such as HIV-1 and Influenza A. Additionally, N4BP1 modulates ubiquitination of signaling proteins (e.g., TRAF3, MAVS) to negatively regulate type I interferon production. Post-translational modifications include phosphorylation and ubiquitination, which control its stability and function. N4BP1 is widely expressed, with highest levels in lymphoid tissues.