Fungal lectin, XCL, is internalized via clathrin-dependent endocytosis and facilitates uptake of other molecules.
The lectin isolated from Xerocomus chrysenteron (XCL) displays a toxic activity towards insects. In order to assess its possible mode of action and to gather useful data for its potential use in insect-resistant transgenic plants, we investigated the effects of XCL at the cellular level. Immunofluorescence microscopy studies revealed that XCL is rapidly internalized into small endocytic vesicles that further coalesce in the perinuclear region. We show that XCL is endocytosed by the clathrin-dependent pathway, and is delivered to late endosome/lysosome compartments. The internalization of XCL seems to be general since it occurs in different cell types such as insect (SF9) or mammalian (NIH-3T3 and Hela) cell lines. In the presence of XCL, the uptake of GFP and BSA is greatly enhanced, demonstrating that XCL facilitates endocytosis. Thus, XCL could serve as a delivery agent to facilitate the endocytosis of proteins that do not enter the cell alone.
Francis
Frédéric
F
Unité de Zoologie Générale et Appliquée, Faculté Universitaire des Sciences Agronomiques, Gembloux, Belgium.
Marty-Detraves
Claire
C
Poincloux
Renaud
R
Baricault
Laurent
L
Fournier
Didier
D
Paquereau
Laurent
L
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D002460:Cell Line; D002746:Chlorpromazine / Q000494:pharmacology; D002966:Clathrin / Q000378:metabolism*; D022163:Clathrin-Coated Vesicles / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology*; D011992:Endosomes / Q000378:metabolism; D005372:Filipin / Q000494:pharmacology; D005658:Fungi / Q000187:drug effects / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D006801:Humans; D037102:Lectins / Q000235:genetics / Q000378:metabolism*; D008164:Luminescent Proteins; D008247:Lysosomes / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D021381:Protein Transport / Q000502:physiology
D000935:Antifungal Agents; D002966:Clathrin; D037102:Lectins; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins; D005372:Filipin; D011188:Potassium; D002746:Chlorpromazine