Liver ubiquitome uncovers nutrient-stress-mediated trafficking and secretion of complement C3.
Fiche publication
Date publication
octobre 2016
Journal
Cell death & disease
Auteurs
Membres identifiés du Cancéropôle Est :
Pr RICCI Roméo, Dr SUMARA Izabela
Tous les auteurs :
Magliarelli HF, Matondo M, Mészáros G, Goginashvili A, Erbs E, Zhang Z, Mihlan M, Wolfrum C, Aebersold R, Sumara I, Ricci R
Lien Pubmed
Résumé
Adaptation to changes in nutrient availability is crucial for cells and organisms. Posttranslational modifications of signaling proteins are very dynamic and are therefore key to promptly respond to nutrient deprivation or overload. Herein we screened for ubiquitylation of proteins in the livers of fasted and refed mice using a comprehensive systemic proteomic approach. Among 1641 identified proteins, 117 were differentially ubiquitylated upon fasting or refeeding. Endoplasmic reticulum (ER) and secretory proteins were enriched in the livers of refed mice in part owing to an ER-stress-mediated response engaging retro-translocation and ubiquitylation of proteins from the ER. Complement C3, an innate immune factor, emerged as the most prominent ER-related hit of our screen. Accordingly, we found that secretion of C3 from the liver and primary hepatocytes as well as its dynamic trafficking are nutrient dependent. Finally, obese mice with a chronic nutrient overload show constitutive trafficking of C3 in the livers despite acute changes in nutrition, which goes in line with increased C3 levels and low-grade inflammation reported for obese patients. Our study thus suggests that nutrient sensing in the liver is coupled to release of C3 and potentially its metabolic and inflammatory functions.
Référence
Cell Death Dis. 2016 Oct;7(10):e2411