NEDD4-binding protein 1; N4BP1 (N4BP1 KIAA0615)

Function

• inhibitor of the E3 ubiquitin-protein ligase ITCH
• acts by interacting with the second WW domain of ITCH, leading to compete with ITCH's substrates & impairing ubiquitination of substrates (putative)
• monoubiquitinated by NEDD4
• polyubiquitinated, leading to its degradation by the proteasome
• sumoylated by SUMO1, abrogating polyubiquitination & subsequent degradation
• desumoylated by SENP1, leading to accumulation in PML nuclear bodies
• phosphorylated upon DNA damage, probably by ATM or ATR
• interacts with NEDD4
• interacts with ITCH (via WW domain 2) (putative)

Structure

belongs to the N4BP1 family

Compartment

• nucleus, nucleolus, PML body (putative)
• primarily localizes to the nucleolus
• also localizes to the PML nuclear bodies, when desumoylated (putative)

Expression

• detected in heart, lung, brain, liver, skeletal muscle, pancreas, kidney, spleen, testis & ovary

More general terms

• Nedd4-binding protein
• nuclear protein

Additional terms

• E3 ubiquitin-protein ligase NEDD4; cell proliferation-inducing gene 53 protein; neural cell expressed developmentally down-regulated protein 4; NEDD-4 (NEDD4, KIAA0093, NEDD4-1, PIG53)

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=9683
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:9683
• UniProt: http://www.uniprot.org/uniprot/O75113.html