Internalization of Sambucus nigra agglutinins I and II in insect midgut CF-203 cells.
In this project, the uptake mechanisms and localization of two lectins from Sambucus nigra, further referred to as S. nigra agglutinin (SNA)-I and SNA-II, into insect midgut CF-203 cells were studied. SNA-I is a chimeric lectin belonging to the class of ribosome-inactivating proteins, whereas SNA-II is a hololectin devoid of enzymatic activity. Internalization of the fluorescein isothiocyanate-labeled lectin was investigated using confocal microscopy. Both lectins were internalized into the cytoplasm of CF-203 cells at similar rates. Preexposure of the insect midgut cells to specific inhibitors of clathrin- and caveolae-mediated endocytosis resulted in an inhibition of lectin uptake in CF-203 cells and caspase-induced cytotoxicity caused by SNA-I and SNA-II, confirming the involvement of both endocytosis pathways. Further studies demonstrated that the uptake mechanism(s) for both lectins required phosphoinositide 3-kinases, but did not depend on the actin cytoskeleton. Since the hololectin SNA-II apparently uses a similar endocytosis pathway as the chimerolectin SNA-I, it can be concluded that the endocytosis process mainly relies on the carbohydrate-binding activity of the lectins under investigation. © 2011 Wiley Periodicals, Inc.
Laboratory of Agrozoology, Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
Shahnaz
S
Shahidi-Noghabi
Els J M
EJ
Van Damme
Winnok H
WH
De Vos
Guy
G
Smagghe
D019870:1-Phosphatidylinositol 4-Kinase / Q000378:metabolism; D000730:Androstadienes / Q000494:pharmacology; D000818:Animals; D001152:Arsenicals / Q000494:pharmacology; D021941:Caveolae / Q000378:metabolism; D002460:Cell Line; D002746:Chlorpromazine / Q000494:pharmacology; D002966:Clathrin / Q000378:metabolism; D015638:Cytochalasin D / Q000494:pharmacology; D004064:Digestive System / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects / Q000502:physiology; D005372:Filipin / Q000494:pharmacology; D016650:Fluorescein-5-isothiocyanate / Q000737:chemistry; D007313:Insecta / Q000378:metabolism*; D018942:Macrolides / Q000494:pharmacology; D018613:Microscopy, Confocal; D009761:Nystatin / Q000494:pharmacology; D037121:Plant Lectins / Q000378:metabolism*; D054788:Ribosome Inactivating Proteins / Q000378:metabolism*; D000077191:Wortmannin
D000730:Androstadienes; D001152:Arsenicals; D002966:Clathrin; D018942:Macrolides; D037121:Plant Lectins; C050600:Sambucus nigra lectins; C029341:oxophenylarsine; D009761:Nystatin; D015638:Cytochalasin D; D005372:Filipin; C040929:bafilomycin A1; D019870:1-Phosphatidylinositol 4-Kinase; D054788:Ribosome Inactivating Proteins; D016650:Fluorescein-5-isothiocyanate; D002746:Chlorpromazine; D000077191:Wortmannin