Fungal lectin, XCL, is internalized via clathrin-dependent endocytosis and facilitates uptake of other molecules

Abstract

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.

Lectins and Their Roles in Pests Control

“…This information gave further support to previous suggestions that the XCL lectins disrupt midgut cells (Francis et al, 2003;Karimi et al, 2008Karimi et al, , 2009). Lectins are highly specific for binding to oligosaccharides, hence if specific carbohydrate is in the surface of tissue it can bind to them and it is believed Table 3.…”

Entomotoxic and nematotoxic lectins and protease inhibitors from fungal fruiting bodies

“…Homodimer 4 Gal na Entomotoxic (Hamshou et al 2013;Hamshou et al 2010b;Hamshou et al 2012;Skamnaki et al 2013) Bleuler-Martinez et al 2011;Fujihashi et al 2003;Fukumori et al 1990;Kochibe and Furukawa 1980;Olausson et al 2010;Olausson et al 2008;Tateno et al 2009;Wimmerova et al 2003) GlcNAc-β1,4-X na nd (Cioci et al 2006;Ueda et al 1999a;Ueda et al 2002;Ueda et al 1999b;Ueda et al 2003) Entomotoxic (Birck et al 2004;Bleuler-Martinez et al 2011;Damian et al 2005;Francis et al 2003;Jaber et al 2008;Jaber et al 2007;…”

“…As an example, XCL was endocytosed by various animal and human cell lines and caused inhibition of proliferation of some of these cell lines (Francis et al 2003;Marty-Detraves et al 2004). A second issue is the way the protein is applied to the crop plant.…”

Purification of a new fungal mannose-specific lectin from Penicillium chrysogenum and its aphicidal properties

“…Mannose-binding lectins are considered as biologically important proteins because mannose is widely distributed in microorganisms and animals including insects (Wong et al 2008). Based on our previous works where fungal lectins were identified with potential insecticidal properties (Francis et al 2003;Karimi et al 2006;Karimi et al 2007) the potential toxic effect of PeCL was investigated on aphids. PeCL lectin was shown to be highly toxic to Myzus persicae when compared to the lectin ConA which is known to have glucose-and mannose-binding properties.…”

“…Lectins have also been purified from fungi and were found to be involved in host recognition, cell surface adhesion, antiproliferative action and endocytosis (Guillot & Konska 1997;Francis et al 2003;Ng 2004;Wang et al 2006). In particular, the use of endophytic fungi producing lectin was found to be a promising way to deliver insecticidal proteins to control sap-sucking pests for crop protection (Qi et al 2011).…”