Differential recognition of lipid domains by two Gb3-binding lectins

• Published in: Scientific reports 2020-06, Vol.10 (1), p.9752-9752, Article 9752
• Main Authors: Schubert, Thomas, Sych, Taras, Madl, Josef, Xu, Maokai, Omidvar, Ramin, Patalag, Lukas J., Ries, Annika, Kettelhoit, Katharina, Brandel, Annette, Mely, Yves, Steinem, Claudia, Werz, Daniel B., Thuenauer, Roland, Römer, Winfried
• Format: Article
• Language: English
• Subjects: 13/95; 14/10; 14/19; 14/34; 14/63; 631/1647/1888; 631/57/2270; 631/80/2373; Adhesins, Bacterial - metabolism; Adhesins, Bacterial - physiology; Bacteriology; Biochemistry, Molecular Biology; Biology; Carbohydrates; Cell Membrane - metabolism; Epithelial cells; Epithelial Cells - metabolism; Experiments; Globotriaosylceramide; Glycosphingolipids - metabolism; Humanities and Social Sciences; Lectins; Lectins - metabolism; Lectins - physiology; Life Sciences; Ligands; Lipid bilayers; Lipid Bilayers - chemistry; Lipids; Membranes; Microbiology and Parasitology; multidisciplinary; Phospholipids; Plasma; Protein Binding - genetics; Protein Binding - physiology; Pseudomonas aeruginosa; Science; Science (multidisciplinary); Shiga toxin; Shiga Toxin - metabolism; Shiga Toxins - metabolism; Shigella dysenteriae; Toxins; Trihexosylceramides - metabolism; Unilamellar Liposomes - metabolism
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-66522-8

The two lectins LecA from Pseudomonas aeruginosa and the B-subunit of Shiga toxin from Shigella dysenteriae (StxB) share the glycosphingolipid globotriaosylceramide (Gb3) as receptor. Counterintuitively, we found that LecA and StxB segregated into different domains after recognizing Gb3 at the plasma membrane of cells. We hypothesized that the orientation of the carbohydrate head group of Gb3 embedded in the lipid bilayer differentially influences LecA and StxB binding. To test this hypothesis, we reconstituted lectin-Gb3 interaction using giant unilamellar vesicles and were indeed able to rebuild LecA and StxB segregation. Both, the Gb3 fatty acyl chain structure and the local membrane environment, modulated Gb3 recognition by LecA and StxB. Specifically, StxB preferred more ordered membranes compared to LecA. Based on our findings, we propose comparing staining patterns of LecA and StxB as an alternative method to assess membrane order in cells. To verify this approach, we re-established that the apical plasma membrane of epithelial cells is more ordered than the basolateral plasma membrane. Additionally, we found that StxB recognized Gb3 at the primary cilium and the periciliary membrane, whereas LecA only bound periciliary Gb3. This suggests that the ciliary membrane is of higher order than the surrounding periciliary membrane.