title: The retinol dehydrogenase Rdh10 localizes to lipid droplets during acyl ester biosynthesis.
abstract: Rdh10 catalyzes the first step of all-trans-retinoic acid biogenesis physiologically, conversion of retinol into retinal. We show that Rdh10 associates predominantly with mitochondria/mitochondrial-associated membrane (MAM) in the absence of lipid droplet biosynthesis, but also locates with lipid droplets during acyl ester biosynthesis. Targeting to lipid droplets requires the 32 N-terminal residues, which include a hydrophobic region followed by a net positive charge. Targeting to mitochondria/MAM and/or the stability of Rdh10 require both the N-terminal and the 48 C-terminal hydrophobic residues. Rdh10 behaves similarly to cellular retinol-binding protein, type 1, which also localizes to mitochondria/MAM before lipid droplet synthesis, and associates with lipid droplets during acyl ester synthesis (Jiang, W., and Napoli, J. L. (2012) Biochem. Biophys. Acta 1820, 859-8692). LRAT, an ER protein, also associates with lipid droplets upon acyl ester biosynthesis. Colocalization of Rdh10, Crbp1, and LRAT on lipid droplets suggests a metabolon that mediates retinol homeostasis.
authors.affiliation: Department of Nutritional Sciences and Toxicology, Graduate Program in Metabolic Biology, University of California, Berkeley, California 94720, USA.
authors.forename: Weiya
authors.initials: W
authors.lastname: Jiang
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Napoli
mesh_terms: D000217:Acyltransferases / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004952:Esters; D006168:Guinea Pigs; D008055:Lipids / Q000737:chemistry; D051379:Mice; D008856:Microscopy, Fluorescence / Q000379:methods; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012176:Retinoids / Q000737:chemistry; D013347:Subcellular Fractions / Q000378:metabolism; D014212:Tretinoin / Q000737:chemistry / Q000378:metabolism; D014801:Vitamin A / Q000737:chemistry
chemical_list: D004952:Esters; D008055:Lipids; D012176:Retinoids; D014801:Vitamin A; D014212:Tretinoin; D000429:Alcohol Oxidoreductases; C113992:trans-retinol dehydrogenase; D000217:Acyltransferases; C056942:lecithin-retinol acyltransferase