A lipid transfer protein ensures nematode cuticular impermeability

• Published in: iScience 2022-11, Vol.25 (11), p.105357-105357, Article 105357
• Main Authors: Njume, Ferdinand Ngale, Razzauti, Adria, Soler, Miguel, Perschin, Veronika, Fazeli, Gholamreza, Bourez, Axelle, Delporte, Cedric, Ghogomu, Stephen M., Poelvoorde, Philippe, Pichard, Simon, Birck, Catherine, Poterszman, Arnaud, Souopgui, Jacob, Van Antwerpen, Pierre, Stigloher, Christian, Vanhamme, Luc, Laurent, Patrick
• Format: Article
• Language: English
• Subjects: Biological sciences; Life Sciences; molecular biology; physiology
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2022.105357

The cuticle of C. elegans is impermeable to chemicals, toxins, and pathogens. However, increased permeability is a desirable phenotype because it facilitates chemical uptake. Surface lipids contribute to the permeability barrier. Here, we identify the lipid transfer protein GMAP-1 as a critical element setting the permeability of the C. elegans cuticle. A gmap-1 deletion mutant increases cuticular permeability to sodium azide, levamisole, Hoechst, and DiI. Expressing GMAP-1 in the hypodermis or transiently in the adults is sufficient to rescue this gmap-1 permeability phenotype. GMAP-1 protein is secreted from the hypodermis to the aqueous fluid filling the space between collagen fibers of the cuticle. In vitro, GMAP-1 protein binds phosphatidylserine and phosphatidylcholine while in vivo, GMAP-1 sets the surface lipid composition and organization. Altogether, our results suggest GMAP-1 secreted by hypodermis shuttles lipids to the surface to form the permeability barrier of C. elegans. [Display omitted] •GMAP-1 is secreted by the hypodermis toward the cuticle of Caenorhabditis elegans•GMAP-1 binds and shuttle phosphoglycerides•GMAP-1 sets the lipid composition of the cuticle•While healthy, gmap-1 mutant displays high cuticular permeability Biological sciences, molecular biology, physiology