Studies on the Mode of Action of Diphtheria Toxin

Goor, Ronald S.; Pappenheimer, Alwin M.; Ames, Elizabeth G.

doi:10.1084/jem.126.5.923

Cited by 37 publications

(19 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, it has been found that toxin and NAD interact mole for mole to form a relatively dissociable complex (7,8). Assuming that this toxin-NAD complex interacts further with transferase II to form an enzymatically inactive product, an equation based on the mass law has been derived that accurately predicts the per cent inhibition of amino acid incorporation in cell-free systems at any given NAD and toxin concentration (3).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Studies on the Mode of Action of Diphtheria Toxin

Pappenheimer

Brown

1968

The Journal of Experimental Medicine

Self Cite

View full text Add to dashboard Cite

It has been shown in previous communications that, in the presence of the specific cofactor nicotinamide adenine dinucleotide (NAD), diphtheria toxin inhibits the transfer of amino acids from aminoacyl-tRNA to the growing polypeptide chains on the ribosomes in cell-free extracts from mammalian cells (1). Although bacterial cell extracts axe completely insensitive to inhibition (1), toxin and NAD inhibit amino acid incorporation in cell-free extracts from chick embryonic tissues (2) and from yeast (3). Collier (4) has demonstrated that toxin and NAD act specifically to cause inactivation of the labile peptide bondforming enzyme, transferase II (s). Goor and Pappenheimer (6) also concluded that transferase n was the site of toxin action in cell extracts and noted that only the soluble form was inactivated; the ribosome-bound enzyme was not affected. It was further observed (3) that the inactivation of transferase II in cell-free systems could be prevented or reversed in the presence of a sufficient concentration of nicotinamide. Finally, it has been found that toxin and NAD interact mole for mole to form a relatively dissociable complex (7,8). Assuming that this toxin-NAD complex interacts further with transferase II to form an enzymatically inactive product, an equation based on the mass law has been derived that accurately predicts the per cent inhibition of amino acid incorporation in cell-free systems at any given NAD and toxin concentration (3).Although the model we have just described adequately explains the action of toxin in cell-free systems, serious difficulties arise when we attempt to use the model to explain the inhibition by toxin of growth of HeLa cells in culture (3). First, the action of toxin on living HeLa cells is not reversible in the presence of *

show abstract

mentioning

confidence: 99%

“…Although bacterial cell extracts axe completely insensitive to inhibition (1), toxin and NAD inhibit amino acid incorporation in cell-free extracts from chick embryonic tissues (2) and from yeast (3). Collier (4) has demonstrated that toxin and NAD act specifically to cause inactivation of the labile peptide bondforming enzyme, transferase II (s).…”

mentioning

confidence: 99%

Studies on the Mode of Action of Diphtheria Toxin

Pappenheimer

Brown

1968

The Journal of Experimental Medicine

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the two following papers, we shall leport the results of studies on the specificity of NAD and its analogues (10), and on the quantitative relationships between NAD, toxin, and transferase II (11). It will be demonstrated that the inactivation by toxin in in vitro systems is reversible under certain conditions.…”

mentioning

confidence: 99%

“…It will be demonstrated that the inactivation by toxin in in vitro systems is reversible under certain conditions. The results have led to the formulation of a model to explain the mode of action of toxin in vitro (11).…”

mentioning

confidence: 99%

Studies on the Mode of Action of Diphtheria Toxin

Goor

Pappenheimer

1967

The Journal of Experimental Medicine

Self Cite

View full text Add to dashboard Cite

The quantitative effect of diphtheria toxin on growth and metabolism of mammalian cells in tissue culture was first investigated by Strauss and Hendee (1). They showed that within 2 hr after addition of an excess of toxin, HeLa cells were no longer able to incorporate amino acids into protein, although aerobic glycolysis and oxygen uptake continued at normal rates for several hours thereafter. Later, it was shown by Kato and Pappenheimer (2) and by Strauss (3) that RNA synthesis is maintained and that intoxicated cells continue to take up and concentrate potassium ions from the external medium (2) for a considerable time after growth ceases. Moreover, the ATP and GTP contents of intoxicated HeLa cells remain at their normal levels for many hours after protein synthesis has been arrested (4) and the cells retain their normal morphological appearance. The effect of toxin on protein synthesis in vivo, therefore, seems to be highly specific. Additional confirmation of the specificity of toxin action comes from recent observations by Duncan and Groman (5) who have shown that toxin blocks synthesis of poliomyelitis viral proteins in infected HeLa cells.Collier and Pappenheimer (6) found that incorporation of amino acids into polypeptides by cell-free systems extracted from Helm cells and from rabbit reticulocytes could be inhibited up to 90% or more by low concentrations of toxin, provided that a specific cofactor~ identified as nicotinamide adenine dinucleotide (NAD) was present. Since the toxin was found to be without effect on the activation of amino acids or on the formation of aminoacyl-sRNA, they concluded that inhibition of protein synthesis by toxin takes place at the level of transfer from aminoacyl-sRNA to the growing peptide chain on the ribosomes.Mammalian cells are known to contain at least two soluble and highly labile enzymes that are required for binding of aminoacyl-sRNA to ribosomes and for catalysis of pepfide bond formation (7,8). Gasior and Moldave (8) have termed these

show abstract

“…Similar concentrations of nicotinamide have been reported to block the action of endogenous ADP-ribosyltransferases in mitochondria (Thomas & Mowbray, 1987). Goor, Pappenheimer & Ames (1967) found that, whilst the action of diphtheria toxin was reversible in isolated membrane preparations, it was irreversible in intact cultured cells. Their failure to observe recovery of cell growth following a 2 mMnicotinamide application more than 6 h after toxin exposure may have been due to degradation of the toxin (Dorland, Middlebrook & Leppla, 1979).…”

Section: E Coli Sta and Theophylline-induced 8ecretionmentioning

confidence: 96%

Reversal and inhibition of cholera toxin‐induced secretion in isolated rabbit ileum.

Falk¹,

Freeman²,

Marshall³

et al. 1990

The Journal of Physiology

View full text Add to dashboard Cite

SUMMARY1. Cholera toxin (1 jig/ml) abolished net fluid absorption by everted sacs of rabbit ileum, leading to net fluid secretion. This action occurred via the toxin-catalysed ADP ribosylation of the stimulatory GTP-binding protein G. which is linked to adenylate cyclase. Nicotinamide (10 mM), a reaction product of ADP ribosylation, reversed cholera toxin-induced secretion, restoring absorption. Lower concentrations of nicotinamide induced partial reversal.2. Nicotinamide (1 mM) blocked the secretory action of cholera toxin applied to ileal sacs. This inhibitory action was more effective in the presence of methionine (1 mM).3. Other inhibitors of ADP ribosylation, benzamide and adenine, blocked the secretory action of cholera toxin. Hypoxanthine, an analogue and metabolite of adenine, was similarly effective.4. Nicotinamide was not, however, effective in blocking or reversing the secretory action of theophylline (10 mM) or of heat-stable E. coli enterotoxin STa. This indicates that nicotinamide has a highly specific action against ADP ribosylating toxins.5. It is proposed that nicotinamide reverses the secretory action of cholera toxin by reversing ADP ribosylation, simply by the law of mass action. This counters the established idea that the effects of cholera and other ADP-ribosylating toxins are irreversible under physiological conditions.

show abstract

Studies on the Mode of Action of Diphtheria Toxin

Cited by 37 publications

References 18 publications

Studies on the Mode of Action of Diphtheria Toxin

Studies on the Mode of Action of Diphtheria Toxin

Studies on the Mode of Action of Diphtheria Toxin

Reversal and inhibition of cholera toxin‐induced secretion in isolated rabbit ileum.

Contact Info

Product

Resources

About