Ricin, the toxic lectin extracted from the castor bean plant (Ricinus communis), consists of an A chain (RTA) and a B chain (RTB). Anti-A chain Abs and anti-B chain Abs can neutralize toxins in vivo and in vitro via blocking the binding of the toxin to the cell. Also, RTB protein is able to serve as an antigen deliver to the mucosal immune system and act as an immunoad...

A major challenge of the postgenomic era is to understand how human genes function together in normal and disease states. In microorganisms, high-density genetic interaction (GI) maps are a powerful tool to elucidate gene functions and pathways. We have developed an integrated methodology based on pooled shRNA screening in mammalian cells for genome-wide identification of genes with relevant ph...

We have investigated the interactions of the plant toxin ricin with sinusoidal endothelial rat liver cells (EC). In these cells, ricin can be bound and internalized via either cell surface galactosyl residues or mannose receptors. Binding and uptake via galactosyl residues and mannose receptors was studied in the presence of mannan (1 mg/ml) and lactose (50 mM) respectively. Whereas most of the...

Ricin is a protein toxin found only in mature castor (Ricinus communis L., Euphorbiaceae) seed that enzymatically destroys the ribosomes of eukaryotes. The presence of ricin in the high protein meal of castor has historically reduced its value as an animal feed. Since ricin has the potential to be used as a chemical warfare and bioterrorism agent, the production and processing of castor has und...

Ricin, a highly toxic plant-derived toxin, is considered a potential weapon in biowarfare and bioterrorism due to its pronounced toxicity, high availability, and ease of preparation. Pulmonary exposure to ricin results in the generation of an acute edematous inflammation followed by respiratory insufficiency and death. Massive neutrophil recruitment to the lungs may contribute significantly to ...

Endocytosed Shiga toxin is transported from the Golgi complex to the endoplasmic reticulum in butyric acid-treated A431 cells. We here examine the extent of this retrograde transport and its regulation. The short B fragment of Shiga toxin is sufficient for transport to the ER. The B fragment of cholera toxin, which also binds to glycolipids, is transported to all the Golgi cisterns, but cannot ...

Many bacterial pathogens that cause different illnesses employ the cytolethal distending toxin (CDT) to induce host cell DNA damage, leading to cell cycle arrest or apoptosis. CDT is a tripartite holotoxin that consists of a DNase I family nuclease (CdtB) bound to two ricin-like lectin domains (CdtA and CdtC). Through the use of structure-based mutagenesis, biochemical and cellular toxicity ass...

The most successful alternative to traditional surgery for ocular muscle spasm treatment is the intramuscular injection of botulinum toxin (BTX), which allows maintenance dynamics and absence scars. However, main BTX disadvantage its nonpermanent effect. A possible way overcoming this obstacle could be represented by enzymatic using plant toxins known as ribosome-inactivating proteins (RIPs). I...

Cytotoxic necrotizing factor 1 (CNF1), a protein produced by pathogenic strains of Escherichia coli, activates the p21 Rho-GTP-binding protein, inducing a profound reorganization of the actin cytoskeleton. CNF1 binds to its cell surface receptor on HEp-2 cells with high affinity (K(d) = 20 pM). In HEp-2 cells the action of CNF1 is not blocked in the presence of filipin, a drug described to redu...