Nedd4-binding partner-1 (N4BP1) has been identified as a protein interactor and a substrate of the homologous to E6AP C terminus (HECT) domain-containing E3 ubiquitin–protein ligase (E3), Nedd4. Here, we describe a previously unrecognized functional interaction between N4BP1 and Itch, a Nedd4 structurally related E3, which contains four WW domains, conferring substrate-binding activity. We show that N4BP1 association with the second WW domain (WW2) of Itch interferes with E3 binding to its substrates. In particular, we found that N4BP1 and p73α, a target of Itch-mediated ubiquitin/proteasome proteolysis, share the same binding site. By competing with p73α for binding to the WW2 domain, N4BP1 reduces the ability of Itch to recruit and ubiquitylate p73α and inhibits Itch autoubiquitylation activity both in in vitro and in vivo ubiquitylation assays.

NEDD4 binding protein 1; N4BP1; KIAA0615

o75113

Human,Mouse,Rat

WB,IHC

WB 1:500-1:1000
IHC 1:50-1:200

~ 120 kDa

Rabbit

This antibody detects endogenous levels of N4BP1 protein.

Synthetic peptide, corresponding to amino acids 391-440 of Human N4BP1.

Polyclonal

Rabbit IgG

The antibody was affinity-purified from rabbit antiserum by affinity-chromatography using epitope-specific immunogen and the purity is > 95% (by SDS-PAGE).

PBS with 0.02% sodium azide, 50% glycerol, pH7.2

1mg/ml

Store at 4℃ short term,and store at -20℃ long term. Avoid freeze-thaw cycles.