@article {154353, title = {Growth factor-triggered de-sialylation controls glycolipid-lectin-driven endocytosis.}, journal = {Nat Cell Biol}, year = {2025}, month = {2025 Feb 21}, abstract = {

Glycolipid-lectin-driven endocytosis controls the formation of clathrin-independent carriers and the internalization of various cargos such as β1 integrin. Whether this process is regulated in a dynamic manner remained unexplored. Here we demonstrate that, within minutes, the epidermal growth factor triggers the galectin-driven endocytosis of cell-surface glycoproteins, such as integrins, that are key regulators of cell adhesion and migration. The onset of this process-mediated by the Na/H antiporter NHE1 as well as the neuraminidases Neu1 and Neu3-requires the pH-triggered enzymatic removal of sialic acids whose presence otherwise prevents galectin binding. De-sialylated glycoproteins are then retrogradely transported to the Golgi apparatus where their glycan make-up is reset to regulate EGF-dependent invasive-cell migration. Further evidence is provided for a role of neuraminidases and galectin-3 in acidification-dependent bone resorption. Glycosylation at the cell surface thereby emerges as a dynamic and reversible regulatory post-translational modification that controls a highly adaptable trafficking pathway.

}, issn = {1476-4679}, doi = {10.1038/s41556-025-01616-x}, url = {https://pubmed.ncbi.nlm.nih.gov/39984654/}, author = {MacDonald, Ewan and Forrester, Alison and Valades-Cruz, Cesar A and Madsen, Thomas D and Hetmanski, Joseph H R and Dransart, Estelle and Ng, Yeap and Godbole, Rashmi and Shp, Ananthan Akhil and Leconte, Ludovic and Chambon, Val{\'e}rie and Ghosh, Debarpan and Pinet, Alexis and Bhatia, Dhiraj and Lombard, B{\'e}rang{\`e}re and Loew, Damarys and Larsen, Martin R and Leffler, Hakon and Lefeber, Dirk J and Clausen, Henrik and Blangy, Anne and Caswell, Patrick and Shafaq-Zadah, Massiullah and Mayor, Satyajit and Weigert, Roberto and Wunder, Christian and Johannes, Ludger} } @article {94677, title = {Ceramide structure dictates glycosphingolipid nanodomain assembly and function.}, journal = {Nat Commun}, volume = {12}, year = {2021}, month = {2021 06 16}, pages = {3675}, abstract = {

Gangliosides in the outer leaflet of the plasma membrane of eukaryotic cells are essential for many cellular functions and pathogenic interactions. How gangliosides are dynamically organized and how they respond to ligand binding is poorly understood. Using fluorescence anisotropy imaging of synthetic, fluorescently labeled GM1 gangliosides incorporated into the plasma membrane of living cells, we found that GM1 with a fully saturated C16:0 acyl chain, but not with unsaturated C16:1 acyl chain, is actively clustered into nanodomains, which depends on membrane cholesterol, phosphatidylserine and actin. The binding of cholera toxin B-subunit (CTxB) leads to enlarged membrane domains for both C16:0 and C16:1, owing to binding of multiple GM1 under a toxin, and clustering of CTxB. The structure of the ceramide acyl chain still affects these domains, as co-clustering with the glycosylphosphatidylinositol (GPI)-anchored protein CD59 occurs only when GM1 contains the fully saturated C16:0 acyl chain, and not C16:1. Thus, different ceramide species of GM1 gangliosides dictate their assembly into nanodomains and affect nanodomain structure and function, which likely underlies many endogenous cellular processes.

}, issn = {2041-1723}, doi = {10.1038/s41467-021-23961-9}, author = {Arumugam, Senthil and Schmieder, Stefanie and Pezeshkian, Weria and Becken, Ulrike and Wunder, Christian and Chinnapen, Dan and Ipsen, John Hjort and Kenworthy, Anne K and Lencer, Wayne and Mayor, Satyajit and Johannes, Ludger} } @article {7080, title = {Quantum dot-loaded monofunctionalized DNA icosahedra for single-particle tracking of endocytic pathways.}, journal = {Nat Nanotechnol}, year = {2016}, month = {2016 Aug 22}, abstract = {

Functionalization of quantum dots (QDs) with a single biomolecular tag using traditional approaches in bulk solution has met with limited success. DNA polyhedra consist of an internal void bounded by a well-defined three-dimensional structured surface. The void can house cargo and the surface can be functionalized with stoichiometric and spatial precision. Here, we show that monofunctionalized QDs can be realized by encapsulating QDs inside DNA icosahedra and functionalizing the DNA shell with an endocytic ligand. We deployed the DNA-encapsulated QDs for real-time imaging of three different endocytic ligands-folic acid, galectin-3 (Gal3) and the Shiga toxin B-subunit (STxB). Single-particle tracking of Gal3- or STxB-functionalized QD-loaded DNA icosahedra allows us to monitor compartmental dynamics along endocytic pathways. These DNA-encapsulated QDs, which bear a unique stoichiometry of endocytic ligands, represent a new class of molecular probes for quantitative imaging of endocytic receptor dynamics.

}, issn = {1748-3395}, doi = {10.1038/nnano.2016.150}, author = {Bhatia, Dhiraj and Arumugam, Senthil and Nasilowski, Michel and Joshi, Himanshu and Wunder, Christian and Chambon, Val{\'e}rie and Prakash, Ved and Grazon, Chlo{\'e} and Nadal, Brice and Maiti, Prabal K and Johannes, Ludger and Dubertret, Benoit and Krishnan, Yamuna} }