Complex sphingolipid profiling and identification of an inositol-phosphorylceramide synthase in Dictyostelium discoideum
Stevanus A. Listian,
Anna-Carina Mazur,
Matthijs Kol,
Edwin Ufelmann,
Sebastian Eising,
Florian Fröhlich,
Stefan Walter,
Joost C.M. Holthuis,
Caroline Barisch
Affiliations
Stevanus A. Listian
Division of Molecular Infection Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
Anna-Carina Mazur
Division of Molecular Infection Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany; Centre for Structural Systems Biology, Hamburg, Germany; Division of Host-Microbe Interactome, Research Center Borstel (FZB) - Leibniz Lung Center, Borstel, Germany; Department of Biology, University of Hamburg, Hamburg, Germany
Matthijs Kol
Division of Molecular Cell Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany; Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
Edwin Ufelmann
Division of Molecular Infection Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
Sebastian Eising
Division of Molecular Membrane Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany
Florian Fröhlich
Division of Molecular Membrane Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany; Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
Stefan Walter
Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
Joost C.M. Holthuis
Division of Molecular Cell Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany; Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany
Caroline Barisch
Division of Molecular Infection Biology, Department of Biology/Chemistry, University of Osnabrück, Osnabrück, Germany; Center of Cellular Nanoanalytics (CellNanOs), University of Osnabrück, Osnabrück, Germany; Centre for Structural Systems Biology, Hamburg, Germany; Division of Host-Microbe Interactome, Research Center Borstel (FZB) - Leibniz Lung Center, Borstel, Germany; Department of Biology, University of Hamburg, Hamburg, Germany; Corresponding author
Summary: Dictyostelium discoideum is a professional phagocyte frequently used to study cellular processes underlying the recognition, engulfment, and infection course of microbial pathogens. Sphingolipids are abundant components of the plasma membrane that bind cholesterol, control membrane properties, participate in signal transmission, and serve as adhesion molecules in recognition processes relevant to immunity and infection. By combining lipidomics with a bioinformatics-based cloning strategy, we show here that D. discoideum produces phosphoinositol-containing sphingolipids with predominantly phytoceramide backbones. Cell-free expression of candidate inositol-phosphorylceramide (IPC) synthases from D. discoideum enabled identification of an enzyme that selectively catalyzes the transfer of phosphoinositol from phosphatidylinositol onto ceramide. The IPC synthase, DdIPCS1, shares multiple sequence motifs with yeast IPC and human sphingomyelin synthases and localizes to the Golgi apparatus as well as the contractile vacuole of D. discoideum. These findings open up important opportunities for exploring a role of sphingolipids in phagocytosis and infection across major evolutionary boundaries.
