N4BP1 (E9A4J) Rabbit mAb #58096

N4BP1 (NEDD4-binding protein 1) was identified as a binding partner and substrate for the HECT domain-containing ubiquitin ligase NEDD4 (1). Subsequently, it was also found to interact with Itch, a ubiquitin ligase structurally similar to NEDD4 (2). Interaction between N4BP1 interferes with the ability of Itch to bind its substrates, including c-Jun and p63 (2). N4BP1 expression has been associated with immune regulation as well as cancer. N4BP1 was identified as an inhibitory factor of NF-κB-mediated MHC-1 expression in neuroblastoma and high expression of N4BP1 was linked to poor overall survival (3). Studies have also found that N4BP1 is a suppressor of cytokine production that can be cleaved and inactivated by caspase-8 (4). N4BP1 can interact with the NF-κB modulator NEMO to suppress NF-κB transcriptional activity (5). Studies have also identified N4BP1 as a potent interferon-inducible HIV-1 restriction factor that targets the degradation of viral mRNA (6).