International Mammalian Genome Society

17th International Mouse Genome Conference

9-12 November 2003, Braunschweig, Germany

Plenary Presentations * Oral Presentations *
Poster Presentations: Behavioural Genetics and Genomics * Development and Stem Cells * Functional Genome Analysis * Mouse Models of Human Disease * Mouse System Biology Bioinformatics * Multigenic and Multifactorial Trait Analysis * Nutrition and Metabolic Disease * Phenotyping Methods Imaging * The Genetics and Genomics of Infectious Disease *
Verne Chapman Memorial Lecture * Table of Contents * Sponsor/Exhibitor List * Awards * Photographs

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POSTER 187 - CHARACTERIZATION OF NSDHL PROTEIN SUBCELLULAR LOCALIZATION

Caldas H
Columbus Children's Research Insitute

Co-Authors: Herman G
Institutions: Columbus Children's Research Insitute

NSDHL, for NAD(P)H steroid dehydrogenase-like, encodes a sterol dehydrogenase involved in the sequential removal of two C-4 methyl groups in post-squalene cholesterol biosynthesis. Mutations in this gene are associated with human CHILD syndrome (congenital hemidysplasia with ichthyosiform nevus and limb defects), an X-linked, male lethal disorder, as well as the mouse mutations bare patches (Bpa) and striated (Str). We have determined the subcellular localization of GFP-tagged proteins encoded by wild type and selected mutant murine Nsdhl alleles using confocal microscopy. In addition to an ER localization commonly found for enzymes of post-squalene cholesterol biosynthesis, we have identified a novel association of NSDHL with lipid droplets, which are ER-derived cytoplasmic structures that contain a neutral lipid core. We demonstrate that ER retrieval and trafficking are necessary for lipid droplet accumulation of the protein. Furthermore the topology of NSDHL on the ER membrane is important for its association with lipid droplets and we propose a model for how this association is likely to occur. The dual localization of NSDHL within ER membranes and on the surface of lipid droplets may provide another mechanism for regulation of the levels and sites of accumulation of intracellular cholesterol.