CeVPS-27 is an endosomal protein required for the molting and the endocytic trafficking of the low-density lipoprotein receptor-related protein 1 in Caenorhabditis elegans.
Class E vacuolar protein-sorting (Vps) proteins were first described in yeast as being involved in receptor-mediated endocytosis and multivesicular body formation. Inactivation by RNA interference of the class E VPS genes of the nematode Caenorhabditis elegans revealed heterogeneous phenotypes. We have further characterized the role of the essential gene Cevps-27, ortholog of human hepatocyte growth factor-regulated tyrosine kinase substrate, during the development of C. elegans. Use of green fluorescent protein fusion constructs and antibody staining revealed that Cevps-27 localizes to endosomal membranes. It is widely expressed but enriched in epithelial cells. Cevps-27 mutants presented enlarged endosomal structures and an accumulation of autophagic vesicles as revealed by electron microscopy and the analysis of the autophagic marker LGG-1. Cevps-27 animals arrested at L2-L3 molt with an inability to degrade their old cuticle. This molting phenotype was more severe when Cevps-27 worms were grown on suboptimal concentrations of cholesterol. Furthermore, defective endocytic trafficking of the low-density lipoprotein receptor-related protein 1 (LRP-1) was also observed in Cevps-27 mutants. These results indicate that CeVPS-27 is required for endosomal and autophagic pathways in C. elegans and plays a crucial role in the control of molting through LRP-1 internalization and cholesterol traffic.
Centre de Génétique Moléculaire, CNRS UPR 2167, Avenue de la terrasse, bâtiment 26, 91198 Gif-sur-Yvette Cedex, France.
Nathalie
N
Roudier
Christophe
C
Lefebvre
Renaud
R
Legouis
D000818:Animals; D030801:Animals, Genetically Modified; D001343:Autophagy; D017173:Caenorhabditis elegans / Q000235:genetics / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D002784:Cholesterol; D046508:Culture Techniques; D011992:Endosomes / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D020868:Gene Silencing; D049452:Green Fluorescent Proteins; D007814:Larva / Q000235:genetics / Q000502:physiology; D026503:Low Density Lipoprotein Receptor-Related Protein-1 / Q000737:chemistry / Q000378:metabolism*; D018613:Microscopy, Confocal; D008854:Microscopy, Electron; D018978:Molting; D009154:Mutation; D010641:Phenotype; D016133:Polymerase Chain Reaction; D021381:Protein Transport; D012313:RNA / Q000096:biosynthesis; D034622:RNA Interference; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000502:physiology*
D029742:Caenorhabditis elegans Proteins; D026503:Low Density Lipoprotein Receptor-Related Protein-1; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins; D012313:RNA; D002784:Cholesterol