scholarly journals Endocytosis and intracellular transport of the glycolipid-binding ligand Shiga toxin in polarized MDCK cells.

1991 ◽  
Vol 113 (3) ◽  
pp. 553-562 ◽  
Author(s):  
K Sandvig ◽  
K Prydz ◽  
M Ryd ◽  
B van Deurs
Keyword(s):  
Golgi Apparatus ◽  
Shiga Toxin ◽  
Intracellular Transport ◽  
Mdck Cells ◽  
Short Chain Fatty Acids ◽  
Subcellular Fractionation ◽  
Shigella Dysenteriae ◽  
Tumor Promoter ◽  
Coated Pits ◽  
Cell Monolayers

The glycolipid-binding cytotoxin produced by Shigella dysenteriae 1, Shiga toxin, binds to MDCK cells (strain 1) only after treatment with short-chain fatty acids like butyric acid or with the tumor promoter 12-O-tetradecanoylphorbol 13-acetate. The induced binding sites were found to be functional with respect to endocytosis and translocation of toxin to the cytosol. Glycolipids that bind Shiga toxin appeared at both the apical and the basolateral surface of polarized MDCK cells grown on filters, and Shiga toxin was found to be endocytosed from both sides of the cells. This was demonstrated by EM of cells incubated with Shiga-HRP and by subcellular fractionation of cells incubated with 125I-labeled Shiga toxin. The data indicated that toxin molecules are endocytosed from coated pits, and that some internalized Shiga toxin is transported to the Golgi apparatus. Fractionation of polarized cells incubated with 125I-Shiga toxin showed that the transport of toxin to the Golgi apparatus was equally efficient from both poles of the cells. After 1-h incubation at 37 degrees C approximately 10% of the internalized toxin was found in the Golgi fractions. The results thus suggest that glycolipids can be efficiently transported to the Golgi apparatus from both sides of polarized MDCK cell monolayers.

scholarly journals The Mitogen-activated Protein Kinase p38 Links Shiga Toxin-dependent Signaling and Trafficking

2008 ◽  
Vol 19 (1) ◽  
pp. 95-104 ◽  
Author(s):  
Sébastien Wälchli ◽  
Sigrid S. Skånland ◽  
Tone F. Gregers ◽  
Silje U. Lauvrak ◽  
Maria L. Torgersen ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Golgi Apparatus ◽  
Shiga Toxin ◽  
Intracellular Transport ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Early Endosomes ◽  
Chemical Inhibitors ◽  
Mitogen Activated Protein ◽  
Interfering Rna

Shiga toxin (Stx) binds to the cell, and it is transported via endosomes and the Golgi apparatus to the endoplasmic reticulum and cytosol, where it exerts its toxic effect. We have recently shown that Stx activates the tyrosine kinase Syk, which in turn induces clathrin phosphorylation and up-regulates Stx uptake. Here, we show that toxin-induced signaling can also regulate another step in intracellular Stx transport. We demonstrate that transport of Stx to the Golgi apparatus is dependent on the mitogen-activated protein kinase p38. Treatment of cells with chemical inhibitors or small interfering RNA targeting p38 inhibited Stx transport to the Golgi and reduced Stx toxicity. This p38 dependence is specific to Stx, because transport of the related toxin ricin was not affected by p38 inhibition. Stx rapidly activated p38, and recruited it to early endosomes in a Ca2+-dependent manner. Furthermore, agonist-induced oscillations in cytosolic Ca2+levels were inhibited upon Stx stimulation, possibly reflecting Stx-dependent local alterations in cytosolic Ca2+levels. Intracellular transport of Stx is Ca2+dependent, and we provide evidence that Stx activates a signaling cascade involving cross talk between Ca2+and p38, to regulate its trafficking to the Golgi apparatus.

scholarly journals Intracellular transport of membrane glycoproteins: two closely related histocompatibility antigens differ in their rates of transit to the cell surface.

1985 ◽  
Vol 101 (3) ◽  
pp. 725-734 ◽  
Author(s):  
D B Williams ◽  
S J Swiedler ◽  
G W Hart
Keyword(s):  
Golgi Apparatus ◽  
Cell Surface ◽  
Intracellular Transport ◽  
B Cell Lymphoma ◽  
Subcellular Fractionation ◽  
Membrane Glycoproteins ◽  
Histocompatibility Antigens ◽  
Membrane Flow ◽  
Surface Appearance ◽  
Beta 2 Microglobulin

The intracellular transport of two closely related membrane glycoproteins was studied in the murine B cell lymphoma line, AKTB-1b. Using pulse-chase radiolabeling, the kinetics of appearance of the class I histocompatibility antigens, H-2Kk and H-2Dk, at the cell surface were compared and found to be remarkably different. Newly synthesized H-2Kk is transported rapidly such that all radiolabeled molecules reach the surface within 1 h. In contrast, the H-2Dk antigen is transported slowly with a half-time of 4-5 h. The rates of surface appearance for the two antigens closely resemble the rates at which their Asn-linked oligosaccharides mature from endoglucosaminidase H (endo H)-sensitive to endo H-resistant forms, a process that occurs in the Golgi apparatus. This suggests that the rate-limiting step in the transport of H-2Dk to the cell surface occurs before the formation of endo H-resistant oligosaccharides in the Golgi apparatus. Subcellular fractionation experiments confirmed this conclusion by identifying the endoplasmic reticulum (ER) as the site where the H-2Dk antigen accumulates. The retention of this glycoprotein in the ER does not appear to be due to a lack of solubility or an inability of the H-2Dk heavy chain to associate with beta 2-microglobulin. Our data is inconsistent with a passive membrane flow mechanism for the intracellular transport of membrane glycoproteins. Rather, it suggests that one or more receptors localized to the ER membrane may mediate the selective transport of membrane glycoproteins out of the ER to the Golgi apparatus. The fact that H-2Kk and H-2Dk are highly homologous (greater than or equal to 80%) indicates that this process can be strongly influenced by limited alterations in protein structure.

scholarly journals Endocytosis from coated pits of Shiga toxin: a glycolipid-binding protein from Shigella dysenteriae 1.

1989 ◽  
Vol 108 (4) ◽  
pp. 1331-1343 ◽  
Author(s):  
K Sandvig ◽  
S Olsnes ◽  
J E Brown ◽  
O W Petersen ◽  
B van Deurs
Keyword(s):  
Shiga Toxin ◽  
Binding Sites ◽  
Vero Cells ◽  
Lipid Binding ◽  
Atp Depletion ◽  
Shigella Dysenteriae ◽  
Coated Vesicle ◽  
Coated Pits ◽  
Normal Medium ◽  
Toxin Binding

Evidence is presented that endocytosis is involved in the transport to the cytosol of the cytotoxin from Shigella dysenteriae 1, Shiga toxin, which acts by removal of a single adenine residue in 28-S ribosomal RNA. Inhibition of endocytosis by ATP depletion of the cells prevented toxin uptake. Exposure of HeLa S3 and Vero cells to toxin at low extracellular pH, where translocation to the cytosol, but not endocytosis is inhibited, allowed the toxin to accumulate in a compartment where it was protected against antibodies to the toxin. Upon transfer of the cells to normal medium endocytosed toxin entered the cytosol. Electron microscopical studies of cells exposed at 0 degrees C to a toxin-horseradish peroxidase (HRP) conjugate, or to unconjugated toxin followed by horse antitoxin antibodies and then protein G-gold, revealed that the Shiga toxin binding sites were randomly distributed on the cell surface, without any preference to, for example, coated pits. In contrast, when cells were exposed to toxin at 37 degrees C, the binding sites were preferentially localized in coated pits. The Shiga-HRP conjugate was also seen in endosomes, lysosomes, and in the Golgi region. Endocytosis by the coated pit/coated vesicle pathway was selectively inhibited by acidification of the cytosol. Under these conditions, both the uptake of toxin-HRP conjugates and intoxication of the cells were inhibited. Evidence from the literature as well as our own results suggest that Shiga toxin binding sites are glycolipids. Thus, Shiga toxin appears to be the first example of a lipid-binding ligand that is endocytosed from coated pits.

Endocytosis, intracellular transport, and cytotoxic action of Shiga toxin and ricin

1996 ◽  
Vol 76 (4) ◽  
pp. 949-966 ◽  
Author(s):  
K. Sandvig ◽  
B. van Deurs
Keyword(s):  
Shiga Toxin ◽  
Intracellular Transport ◽  
Retrograde Transport ◽  
Cytotoxic Action ◽  
Coated Pits ◽  
Polarized Epithelia ◽  
Protein Toxins ◽  
A Cell ◽  
Membrane Bound ◽  
Golgi Network

Protein toxins such as ricin and Shiga toxin with intracellular targets have to be endocytosed and translocated to the cytosol to inhibit the protein synthesis and thereby kill the cell. Ricin is internalized by both clathrin-dependent and -independent endocytic mechanisms, whereas Shiga toxin seems to be taken up exclusively from clathrin-coated pits. After endocytosis, internalized membrane and content are delivered to endosomes, where sorting for further routing in the cell takes place. Toxins that remain membrane bound at low endosomal pH can be recycled to the cell surface or transcytosed in polarized epithelia. A large proportion of internalized toxin is transported to lysosomes for degradation. Most importantly, a fraction of the internalized ricin and Shiga toxin molecules is delivered to the trans-Golgi network (TGN). Shiga toxin can, in some very sensitive cells, be transported retrogradely through the Golgi cisterns all the way back to the endoplasmic reticulum (ER), and it is possible that also ricin is transported retrogradely to the ER. In this review, a cell biological overview of these intracellular transport steps is presented, and evidence is provided that the delivery to the TGN and the subsequent retrograde transport to the ER are required for optimal intoxication. Moreover, it is argued that knowledge of this transport is important for targeted drug delivery such as the application of immunotoxins in cancer therapy.

scholarly journals Viral glycoproteins destined for apical or basolateral plasma membrane domains traverse the same Golgi apparatus during their intracellular transport in doubly infected Madin-Darby canine kidney cells.

1984 ◽  
Vol 98 (4) ◽  
pp. 1304-1319 ◽  
Author(s):  
M J Rindler ◽  
I E Ivanov ◽  
H Plesken ◽  
E Rodriguez-Boulan ◽  
D D Sabatini
Keyword(s):  
Plasma Membrane ◽  
Golgi Apparatus ◽  
G Protein ◽  
Intracellular Transport ◽  
Mdck Cells ◽  
Simian Virus ◽  
Apical Plasma Membrane ◽  
Madin Darby Canine Kidney ◽  
Darby Canine Kidney ◽  
Canine Kidney

Madin-Darby canine kidney (MDCK) cells can sustain double infection with pairs of viruses of opposite budding polarity (simian virus 5 [SV5] and vesicular stomatitis virus [VSV] or influenza and VSV), and we observed that in such cells the envelope glycoproteins of the two viruses are synthesized simultaneously and assembled into virions at their characteristic sites. Influenza and SV5 budded exclusively from the apical plasma membrane of the cells, while VSV emerged only from the basolateral surfaces. Immunoelectron microscopic examination of doubly infected MDCK cells showed that the influenza hemagglutinin (HA) and the VSV G glycoproteins traverse the same Golgi apparatus and even the same Golgi cisternae. This indicates that the pathways of the two proteins towards the plasma membrane do not diverge before passage through the Golgi apparatus and therefore that critical sorting steps must take place during or after passage of the glycoproteins through this organelle. After its passage through the Golgi, the HA accumulated primarily at the apical membrane, where influenza virion assembly occurred. A small fraction of HA did, however, appear on the lateral surface and was incorporated into the envelope of budding VSV virions. Although predominantly found on the basolateral surface, significant amounts of G protein were observed on the apical plasma membrane well before disruption of the tight junctions was detectable. Nevertheless, assembly of VSV virions was restricted to the basolateral domain and in doubly infected cells the G protein was only infrequently incorporated into the envelope of budding influenza virions. These observations indicate that the site of VSV budding is not determined exclusively by the presence of G polypeptides. Therefore, it is likely that, at least for VSV, other cellular or viral components are responsible for the selection of the appropriate budding domain.

Changes Occur in Plasma Membrane Turnover when K562 Leukemia Cells are Induced to Differentiate

1982 ◽  
Vol 40 ◽  
pp. 286-287
Author(s):  
L. M. Marshall
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Intracellular Transport ◽  
Parent Cell ◽  
Membrane Turnover ◽  
Coated Pits ◽  
Surface Distribution ◽  
Specific Proteins ◽  
Erythroleukemic Cell ◽  
Specific Membrane

A human erythroleukemic cell line, metabolically blocked in a late stage of erythropoiesis, becomes capable of differentiation along the normal pathway when grown in the presence of hemin. This process is characterized by hemoglobin synthesis followed by rearrangement of the plasma membrane proteins and culminates in asymmetrical cytokinesis in the absence of nuclear division. A reticulocyte-like cell buds from the nucleus-containing parent cell after erythrocyte specific membrane proteins have been sequestered into its membrane. In this process the parent cell faces two obstacles. First, to organize its erythrocyte specific proteins at one pole of the cell for inclusion in the reticulocyte; second, to reduce or abolish membrane protein turnover since hemoglobin is virtually the only protein being synthesized at this stage. A means of achieving redistribution and cessation of turnover could involve movement of membrane proteins by a directional lipid flow. Generation of a lipid flow towards one pole and accumulation of erythrocyte-specific membrane proteins could be achieved by clathrin coated pits which are implicated in membrane endocytosis, intracellular transport and turnover. In non-differentiating cells, membrane proteins are turned over and are random in surface distribution. If, however, the erythrocyte specific proteins in differentiating cells were excluded from endocytosing coated pits, not only would their turnover cease, but they would also tend to drift towards and collect at the site of endocytosis. This hypothesis requires that different protein species are endocytosed by the coated vesicles in non-differentiating than by differentiating cells.

scholarly journals Differential Response of the Human Renal Proximal Tubular Epithelial Cell Line HK-2 to Shiga Toxin Types 1 and 2

2011 ◽  
Vol 79 (9) ◽  
pp. 3527-3540 ◽  
Author(s):  
Erin K. Lentz ◽  
Dinorah Leyva-Illades ◽  
Moo-Seung Lee ◽  
Rama P. Cherla ◽  
Vernon L. Tesh
Keyword(s):  
Epithelial Cell ◽  
Cell Line ◽  
Shiga Toxin ◽  
Renal Damage ◽  
Diarrheal Disease ◽  
Shigella Dysenteriae ◽  
Parp Cleavage ◽  
Epithelial Cell Line ◽  
Cytotoxic Action ◽  
Content Type

ABSTRACTShiga toxins (Stxs) are expressed by the enteric pathogensShigella dysenteriaeserotype 1 and certain serotypes ofEscherichia coli. Stx-producing bacteria cause bloody diarrhea with the potential to progress to acute renal failure. Stxs are potent protein synthesis inhibitors and are the primary virulence factors responsible for renal damage that may follow diarrheal disease. We explored the use of the immortalized human proximal tubule epithelial cell line HK-2 as anin vitromodel of Stx-induced renal damage. We showed that these cells express abundant membrane Gb3and are differentially susceptible to the cytotoxic action of Stxs, being more sensitive to Shiga toxin type 1 (Stx1) than to Stx2. At early time points (24 h), HK-2 cells were significantly more sensitive to Stxs than Vero cells; however, by 72 h, Vero cell monolayers were completely destroyed while some HK-2 cells survived toxin challenge, suggesting that a subpopulation of HK-2 cells are relatively toxin resistant. Fluorescently labeled Stx1 B subunits localized to both lysosomal and endoplasmic reticulum (ER) compartments in HK-2 cells, suggesting that differences in intracellular trafficking may play a role in susceptibility to Stx-mediated cytotoxicity. Although proinflammatory cytokines were not upregulated by toxin challenge, Stx2 selectively induced the expression of two chemokines, macrophage inflammatory protein-1α (MIP-1α) and MIP-1β. Stx1 and Stx2 differentially activated components of the ER stress response in HK-2 cells. Finally, we demonstrated significant poly(ADP-ribose) polymerase (PARP) cleavage after exposure to Stx1 or Stx2. However, procaspase 3 cleavage was undetectable, suggesting that HK-2 cells may undergo apoptosis in response to Stxs in a caspase 3-independent manner.

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