Biomaterial Database

Ionic requirements for entry of Shiga toxin from Shigella dysenteriae 1 into cells. 1987

K Sandvig, and J E Brown

The ionic requirements for entry of Shiga toxin into cells were examined by measuring inhibition of protein synthesis after short-term incubations with toxin. The sensitivity of Vero cells and HeLa cells to Shiga toxin was strongly dependent on the divalent cation present. Vero cells were most sensitive in the presence of CaCl2 and SrCl2, whereas HeLa cells were equally sensitive in the presence of MgCl2, SrCl2, and CaCl2. Both cell lines were protected by BaCl2, CoCl2, and MnCl2. Inhibitors of Ca2+ transport, like verapamil, D600, and Co2+ as well as the calcium-ionophores A23187 and ionomycin, protected both cell lines. HEp-2 cells were protected against Shiga toxin by a high concentration of potassium in the medium as well as by potassium depletion of the cells. Substitution of chloride in the medium with slowly permeable anions, like SO42- and SCN-, protected the cells against Shiga toxin. High concentrations of the ionophore nigericin that increase pH of acidic intracellular vesicles did not protect Vero cells against Shiga toxin. Shiga Toxin X-114 at pH values below 4.5. This binding was shifted to higher pH values after pretreatment of the toxin with dithiothreitol. The results indicate that Ca2+ transport through physiologically occurring Ca2+ channels is required for entry of Shiga toxin into cells. Furthermore, the sensitivity of cells of Shiga toxin is strongly dependent on the anions present.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D011092	Polyethylene Glycols	Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.	Macrogols,Polyoxyethylenes,Carbowax,Macrogol,Polyethylene Glycol,Polyethylene Oxide,Polyethyleneoxide,Polyglycol,Glycol, Polyethylene,Glycols, Polyethylene,Oxide, Polyethylene,Oxides, Polyethylene,Polyethylene Oxides,Polyethyleneoxides,Polyglycols,Polyoxyethylene
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002460	Cell Line	Established cell cultures that have the potential to propagate indefinitely.	Cell Lines,Line, Cell,Lines, Cell
D006863	Hydrogen-Ion Concentration	The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH	pH,Concentration, Hydrogen-Ion,Concentrations, Hydrogen-Ion,Hydrogen Ion Concentration,Hydrogen-Ion Concentrations
D000838	Anions	Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.	Anion
D001427	Bacterial Toxins	Toxic substances formed in or elaborated by bacteria; they are usually proteins with high molecular weight and antigenicity; some are used as antibiotics and some to skin test for the presence of or susceptibility to certain diseases.	Bacterial Toxin,Toxins, Bacterial,Toxin, Bacterial
D001692	Biological Transport	The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.	Transport, Biological,Biologic Transport,Transport, Biologic
D012762	Shigella dysenteriae	A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that is extremely pathogenic and causes severe dysentery. Infection with this organism often leads to ulceration of the intestinal epithelium.	Bacillus dysenteriae,Bacillus dysentericus,Bacillus shigae,Eberthella dysenteriae,Shigella shigae