Spatial control of lipid droplet proteins by the ERAD ubiquitin ligase Doa10

• Annamaria Ruggiano ^[1] ; Gabriel Mora ^[2] ; Laura Buxó ^[2] ; Pedro Carvalho ^[2]
  1. [1] 1 Centre for Genomic Regulation (CRG) Barcelona Institute of Science and Technology Barcelona Spain; 2 Universitat Pompeu Fabra (UPF) Barcelona Spain; Present address: Department of Molecular Cell BiologyMax Planck Institute of BiochemistryMartinsriedGermany
  2. [2] 1 Centre for Genomic Regulation (CRG) Barcelona Institute of Science and Technology Barcelona Spain; 2 Universitat Pompeu Fabra (UPF) Barcelona Spain
• Localización: EMBO journal: European Molecular Biology Organization, ISSN 0261-4189, Vol. 35, Nº. 15, 2016, págs. 1644-1655
• Idioma: inglés
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• Resumen

  • The endoplasmic reticulum (ER) plays a central role in the biogenesis of most membrane proteins. Among these are proteins localized to the surface of lipid droplets (LDs), fat storage organelles delimited by a phospholipid monolayer. The LD monolayer is often continuous with the membrane of the ER allowing certain membrane proteins to diffuse between the two organelles. In these connected organelles, how some proteins concentrate specifically at the surface of LDs is not known. Here, we show that the ERAD ubiquitin ligase Doa10 controls the levels of some LD proteins. Their degradation is dependent on the localization to the ER and appears independent of the folding state. Moreover, we show that by degrading the ER pool of these LD proteins, ERAD contributes to restrict their localization to LDs. The signals for LD targeting and Doa10‐mediated degradation overlap, indicating that these are competing events. This spatial control of protein localization is a novel function of ERAD that might contribute to generate functional diversity in a continuous membrane system.