title: Tissue- and paralogue-specific functions of acyl-CoA-binding proteins in lipid metabolism in Caenorhabditis elegans.
abstract: ACBP (acyl-CoA-binding protein) is a small primarily cytosolic protein that binds acyl-CoA esters with high specificity and affinity. ACBP has been identified in all eukaryotic species, indicating that it performs a basal cellular function. However, differential tissue expression and the existence of several ACBP paralogues in many eukaryotic species indicate that these proteins serve distinct functions. The nematode Caenorhabditis elegans expresses seven ACBPs: four basal forms and three ACBP domain proteins. We find that each of these paralogues is capable of complementing the growth of ACBP-deficient yeast cells, and that they exhibit distinct temporal and tissue expression patterns in C. elegans. We have obtained loss-of-function mutants for six of these forms. All single mutants display relatively subtle phenotypes; however, we find that functional loss of ACBP-1 leads to reduced triacylglycerol (triglyceride) levels and aberrant lipid droplet morphology and number in the intestine. We also show that worms lacking ACBP-2 show a severe decrease in the β-oxidation of unsaturated fatty acids. A quadruple mutant, lacking all basal ACBPs, is slightly developmentally delayed, displays abnormal intestinal lipid storage, and increased β-oxidation. Collectively, the present results suggest that each of the ACBP paralogues serves a distinct function in C. elegans.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark.
authors.forename: Ida C
authors.initials: IC
authors.lastname: Elle
authors.forename: Karina T
authors.initials: KT
authors.lastname: Simonsen
authors.forename: Louise C B
authors.initials: LC
authors.lastname: Olsen
authors.forename: Pernille K
authors.initials: PK
authors.lastname: Birck
authors.forename: Sidse
authors.initials: S
authors.lastname: Ehmsen
authors.forename: Simon
authors.initials: S
authors.lastname: Tuck
authors.forename: Thuc T
authors.initials: TT
authors.lastname: Le
authors.forename: Nils J
authors.initials: NJ
authors.lastname: Færgeman
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics; D029742:Caenorhabditis elegans Proteins / Q000502:physiology; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D026261:Diazepam Binding Inhibitor / Q000378:metabolism*; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D050356:Lipid Metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000502:physiology; D013217:Starvation / Q000378:metabolism; D014157:Transcription Factors / Q000502:physiology; D014280:Triglycerides / Q000378:metabolism
chemical_list: D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D026261:Diazepam Binding Inhibitor; D005231:Fatty Acids, Unsaturated; C505159:NHR-49 protein, C elegans; D020033:Protein Isoforms; D018160:Receptors, Cytoplasmic and Nuclear; D014157:Transcription Factors; D014280:Triglycerides