A Dictyostelium long chain fatty acyl coenzyme A-synthetase mediates fatty acid retrieval from endosomes.
We have identified a subset of Dictyostelium endosomes that carry a long chain fatty acyl coenzyme A-synthetase (LC-FACS 1) on their cytosolic surface. Immunofluorescence studies and observations using GFP-fusion proteins collectively suggest that LC-FACS 1 associates with endosomes a few minutes after their formation, remains bound through the acidic phase of endocytic maturation and dissociates early in the phase where the endosomal content is neutralised prior to exocytosis. Mutants in the fcsA gene, encoding the LC-FACS 1 protein, were constructed by homologous recombination. These cells show a strong defect in the intracellular accumulation of fatty acids, either taken up together with the liquid medium or bound to the surface of particles. Because the mutant cells are otherwise fully competent for macropinocytosis and phagocytosis, we conclude that the LC-FACS 1 protein mediates the retrieval of fatty acids from the lumen of endosomes into the cytoplasm.
von Löhneysen
Katharina
K
Abteilung Zellbiologie, Universität Kassel, Kassel, Germany.
Pawolleck
Nadine
N
Rühling
Harald
H
Maniak
Markus
M
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport / Q000502:physiology; D002458:Cell Fractionation; D003066:Coenzyme A Ligases / Q000235:genetics / Q000378:metabolism*; D004023:Dictyostelium / Q000166:cytology / Q000201:enzymology*; D011992:Endosomes / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
D005227:Fatty Acids; D011993:Recombinant Fusion Proteins; D003066:Coenzyme A Ligases