title: Regulation of functional diversity within the Nedd4 family by accessory and adaptor proteins.
abstract: Ubiquitination is essential in mediating diverse cellular functions including protein degradation and trafficking. Ubiquitin-protein (E3) ligases determine the substrate specificity of the ubiquitination process. The Nedd4 family of E3 ligases is an evolutionarily conserved family of proteins required for the ubiquitination of a large number of cellular targets. As a result, this family regulates a wide variety of cellular processes including transcription, stability and trafficking of plasma membrane proteins, and the degradation of misfolded proteins. The modular architecture of the proteins, comprising a C2 domain, multiple WW domains and a catalytic domain, enables diverse intermolecular interactions and recruitment to various subcellular locations. The WW domains commonly mediate interaction with substrate proteins; however, an increasing number of Nedd4 targets do not contain obvious WW domain-interaction motifs suggesting the involvement of accessory proteins. This review discusses recent insights into how accessory and adaptor proteins modulate the activities of Nedd4 family members, including recruitment of novel substrates, alteration of subcellular localisation and effects on ubiquitination.
authors.affiliation: Molecular Regulation Laboratory, Hanson Institute, IMVS, Adelaide, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Shearwin-Whyatt
authors.forename: Hazel E
authors.initials: HE
authors.lastname: Dalton
authors.forename: Natalie
authors.initials: N
authors.lastname: Foot
authors.forename: Sharad
authors.initials: S
authors.lastname: Kumar
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000818:Animals; D056827:Endosomal Sorting Complexes Required for Transport; D006801:Humans; D000075702:Nedd4 Ubiquitin Protein Ligases; D021381:Protein Transport; D015398:Signal Transduction; D013379:Substrate Specificity; D025801:Ubiquitin / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000145:classification / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D056827:Endosomal Sorting Complexes Required for Transport; D025801:Ubiquitin; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; D044767:Ubiquitin-Protein Ligases