title: An Essential Role of Nedd4-2 in the Ubiquitination, Expression, and Function of Organic Anion Transporter-3.
abstract: Organic anion transporter-3 (OAT3) is a member of the organic anion transporter family that mediates the body disposition of a diverse array of clinically important drugs. We previously demonstrated that activation of protein kinase C (PKC) inhibits OAT3 transport activity by accelerating OAT3 internalization from cell surface into intracellular compartments. In the current study, we established that PKC-induced inhibition of OAT3 transport activity occurred through an enhanced OAT3 ubiquitination, a process catalyzed by an E3 ubiquitin-protein ligase Nedd4-2 (neural precursor cell expressed, developmentally downregulated 4-2). Overexpression of Nedd4-2 enhanced OAT3 ubiquitination, decreased OAT3 expression at the cell surface, and inhibited OAT3 transport activity. In contrast, overexpression of the ubiquitin ligase-dead mutant Nedd4-2/C821A or siRNA knockdown of endogenous Nedd4-2 had opposite effects on OAT3. Furthermore, immunoprecipitation experiments conducted both in culture cells and with rat kidney slices showed that there was a physical interaction between OAT3 and Nedd4-2. In conclusion, our results provided the first evidence that Nedd4-2 is an important regulator for OAT3 ubiquitination, expression, and transport activity.
authors.affiliation: Department of Pharmaceutics, Rutgers University , Piscataway, New Jersey 08854, United States.
authors.forename: Da
authors.initials: D
authors.lastname: Xu
authors.affiliation: Department of Pharmaceutics, Rutgers University , Piscataway, New Jersey 08854, United States.
authors.forename: Haoxun
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutics, Rutgers University , Piscataway, New Jersey 08854, United States.
authors.forename: Guofeng
authors.initials: G
authors.lastname: You
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004705:Endocytosis / Q000502:physiology; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D007668:Kidney / Q000166:cytology / Q000378:metabolism*; D008297:Male; D000075702:Nedd4 Ubiquitin Protein Ligases; D029362:Organic Anion Transporters, Sodium-Independent / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D021381:Protein Transport; D051381:Rats; D017207:Rats, Sprague-Dawley; D025801:Ubiquitin / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; D029362:Organic Anion Transporters, Sodium-Independent; D025801:Ubiquitin; C114338:organic anion transport protein 3; C000618479:NEDD4L protein, rat; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; C000618484:Nedd4 protein, rat; C000618485:Nedd4L protein, human; D044767:Ubiquitin-Protein Ligases; D011493:Protein Kinase C
keywords: drug transporter; membrane transporter; regulation; ubiquitin ligase; ubiquitination