Pathogenesis of shigella diarrhea. XI. Isolation of a shigella toxin-binding glycolipid from rabbit jejunum and HeLa cells and its identification as globotriaosylceramide.

Abstract

Shigella toxin is a multimeric protein consisting of one A subunit (M,., 32,000) and five B subunits (Mr, 6,500) (1). It is produced by all species of the genus and is believed to play an important role in pathogenesis of clinical shigellosis (2). Shigella toxin is particularly interesting because several different biological effects are mediated by the same highly purified molecule (1, 3). For example, it causes fluid secretion when placed in the lumen of rabbit small intestine (enterotoxicity) (2), but results in delayed limb paralysis and then death if administered parenterally in the same species (neurotoxicity) (4). When directly injected into the vagus nerve trunk of rats, shigella toxin travels in retrograde fashion via the axon to the neuronal cell body, causing dissolution of Nissl substance and death of the neuron (neuronotoxicity) (5). It is also lethal to certain cell culture lines (cytotoxicity) due to inhibition of protein synthesis (6, 7). The latter effect has also been shown in cell-free protein synthesis systems (8). The mechanism appears to be an irreversible and probably catalytic inactivation of the 60 S ribosomal subunit by the toxin A subunit (9).It is not known how shigella toxin produces these various manifestations. It is possible that there are distinctive binding sites on different tissues for the toxin B subunit that result in diverse effects and that the B subunit has multiple binding domains that recognize these distinctive receptors. It is also conceivable that direct binding of the A subunit could cause some of the observed effects. In HeEa cells, the cytotoxic effect of shigella toxin appears to be related to binding of the B subunit to an N-linked glycoprotein on the cell surface that contains oligomeric ~31---~4 linked N-acetyl-D-glucosamine (GIcNAc) I. The evidence for

Globotriaosylceramide (Gb3) content in HeLa cells is correlated to Shiga toxin-induced cytotoxicity and Gb3 synthase expression

“…The results of epidemiological and experimental studies have indicated Stx2 may be of greater clinical significance than Stx1 (6,7). All shiga toxins consist of a single A subunit in association with several pentamer B subunits (8)(9)(10). The A subunit as a ribosomal RNA N-glycosidase removes the adenine of the 28S RNA within the 60S ribosomal subunit (11), thereby rendering ribosomes inactive for protein synthesis (12).…”

Les récepteurs des entérotoxines bactériennes

“…Le globotriosylcéramide Gb3 (le glycolipide du groupe sanguin P) est le récepteur à la fois pour la toxine Shiga et pour les toxines Stx1 et Stx2 [71,94,159]. Le récepteur de la toxine Shiga a été mis en évidence principalement sur les cellules HeLa et les cellules Véro.…”

Study on induction of apoptosis on HeLa and Vero cells by recombinant shiga toxin and its subunits

“…Stx consists of a single A subunit and a pentamer of B subunits (Jacewicz et al 1986;Lingwood et al 1998; S. Bouzari Á M. Oloomi (&) Á K. Azadmanesh Molecular Biology Unit, Pasteur Institute of Iran, Pasteur Ave., 13164 Tehran, Iran e-mail: manaoloomi@yahoo.com Endo et al 1988). The B subunit of Stx (StxB) is responsible for the attachment of the holotoxin to the cell surface by binding to the functional receptor globotriaosylceramide (Gb3/ CD77) (Jacewicz et al 1986).…”

“…Stx consists of a single A subunit and a pentamer of B subunits (Jacewicz et al 1986;Lingwood et al 1998; S. Bouzari Á M. Oloomi (&) Á K. Azadmanesh Molecular Biology Unit, Pasteur Institute of Iran, Pasteur Ave., 13164 Tehran, Iran e-mail: manaoloomi@yahoo.com Endo et al 1988). The B subunit of Stx (StxB) is responsible for the attachment of the holotoxin to the cell surface by binding to the functional receptor globotriaosylceramide (Gb3/ CD77) (Jacewicz et al 1986). The A subunit of Stx has N-glycosidase activity and cleaves a single adenine residue located in a prominent loop structure of the 28S ribosomal RNA of eukaryotic ribosome, which creates inhibition of protein synthesis and death of the cells resulting in cell cytotoxicity (Endo et al 1988).…”