title: Subcellular Localization and Polymorphism of Bovine FABP4 in Bovine Intramuscular Adipocytes.
abstract: Fatty acid binding protein 4 (FABP4) I74 V, a gene polymorphism associated with unsaturated fatty acid contents, was discovered in Japanese Black cattle. Individuals with FABP4 I/I genotype contain a significantly high level of palmitoleic acid compared to those with FABP4 V/V genotype. It remains unknown how the FABP4 polymorphism leads to different palmitoleic acid contents. We overexpressed FABP4 of different genotypes in bovine intramuscular preadipocytes and examined whether the intracellular localization of FABP4 and the expression levels of lipid metabolism-related genes were different among cells expressing different genotypes. Nuclear localization was observed for the FABP4 V/V, while the FABP4 I/I almost did not. The cells expressing FABP4 of different genotypes were comparable in terms of the expression levels of genes involved in lipid metabolism. FABP4 I/I was localized in most of the lipid droplets 4 days after differentiation induction, whereas approximately 25% lipid droplet co-localized with FABP4 in cells expressing FABP4 V/V. The lipid droplet size increased when palmitoleic acid was added compared to the size observed when palmitic acid was added. These results suggest that lipid droplet enlargement caused by palmitoleic acid and genotype-dependent differences in the fatty acid transporting capacity underlie variations in palmitoleic acid content among FABP4 polymorphisms.
authors.affiliation: a Department of Interdisciplinary Genome Sciences and Cell Metabolism , Institute for Biomedical Sciences, Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University , Nagano , Japan.|b Graduate School of Agriculture , Shinshu University , Nagano , Japan.|c Interdisciplinary Graduate School of Science and Technology , Shinshu University , Nagano , Japan.
authors.forename: Shinichi
authors.initials: S
authors.lastname: Yonekura
authors.affiliation: b Graduate School of Agriculture , Shinshu University , Nagano , Japan.
authors.forename: Shohei
authors.initials: S
authors.lastname: Hirota
authors.affiliation: b Graduate School of Agriculture , Shinshu University , Nagano , Japan.
authors.forename: Honami
authors.initials: H
authors.lastname: Miyazaki
authors.affiliation: c Interdisciplinary Graduate School of Science and Technology , Shinshu University , Nagano , Japan.
authors.forename: Yukako
authors.initials: Y
authors.lastname: Tokutake
mesh_terms: D017667:Adipocytes / Q000737:chemistry* / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D002417:Cattle; D002467:Cell Nucleus; D050556:Fatty Acid-Binding Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D005229:Fatty Acids, Monounsaturated / Q000378:metabolism; D066292:Lipid Droplets / Q000378:metabolism; D008460:Meat; D009132:Muscles / Q000166:cytology*; D019308:Palmitic Acid / Q000378:metabolism
chemical_list: D050556:Fatty Acid-Binding Proteins; D005229:Fatty Acids, Monounsaturated; C008757:palmitoleic acid; D019308:Palmitic Acid
keywords: Adipocyte; FABP4; Japanese black cattle; polymorphism; unsaturated fatty acid