scholarly journals Differential extractability of influenza virus hemagglutinin during intracellular transport in polarized epithelial cells and nonpolar fibroblasts.

1989 ◽  
Vol 108 (3) ◽  
pp. 821-832 ◽  
Author(s):  
J E Skibbens ◽  
M G Roth ◽  
K S Matlin

Biochemical changes in the influenza virus hemagglutinin during intracellular transport to the apical plasma membrane of epithelial cells were investigated in Madin-Darby canine kidney (MDCK) cells and in LLC-PK1 cells stably transfected with a hemagglutinin gene. After pulse-labeling a substantial fraction of hemagglutinin was observed to become insoluble in isotonic solutions of Triton X-100. Insolubility of hemagglutinin was detected late in the transport pathway after addition of complex sugars in the Golgi complex but before insertion of the protein in the plasma membrane. Insolubility was not dependent on oligosaccharide modification since deoxymannojirimycin (dMM), which inhibits mannose trimming, failed to prevent its onset. Insolubility was not due to assembly of virus particles at the plasma membrane because insoluble hemagglutinin was also observed in transfected cells. Hemagglutinin insolubility was also seen in MDCK cells cultured in suspension and in chick embryo fibroblasts, indicating that insolubility and plasma membrane polarity are not simply correlated. In addition to insolubility, an apparent transport-dependent reduction of the disulfide bond linking HA1 and HA2 in hemagglutinin was detected. Because of the timing of both insolubility and the loss of the disulfide bond, these modifications may be important in the delivery of the hemagglutinin to the cell surface.

1990 ◽  
Vol 1 (12) ◽  
pp. 921-936 ◽  
Author(s):  
M J van Zeijl ◽  
K S Matlin

The effects of microtubule perturbation on the transport of two different viral glycoproteins were examined in infected Madin-Darby canine kidney (MDCK) cells grown on both permeable and solid substrata. Quantitative biochemical analysis showed that the microtubule-depolymerizing drug nocodazole inhibited arrival of influenza hemagglutinin on the apical plasma membrane in MDCK cells grown on both substrata. In contrast, the microtubule-stabilizing drug taxol inhibited apical appearance of hemagglutinin only when MDCK cells were grown on permeable substrata. On the basis of hemagglutinin mobility on sodium dodecyl sulfate gels and its sensitivity to endo H, it was evident that nocodazole and taxol arrested hemagglutinin at different intracellular sites. Neither drug caused a significant increase in the amount of hemagglutinin detected on the basolateral plasma membrane domain. In addition, neither drug had any noticeable effect on the transport of the vesicular stomatitis virus (VSV)-G protein to the basolateral surface. These results shed light on previous conflicting reports using this model system and support the hypothesis that microtubules play a role in the delivery of membrane glycoproteins to the apical, but not the basolateral, domain of epithelial cells.


1999 ◽  
Vol 145 (1) ◽  
pp. 141-151 ◽  
Author(s):  
Rosa Puertollano ◽  
Fernando Martín-Belmonte ◽  
Jaime Millán ◽  
María del Carmen de Marco ◽  
Juan P. Albar ◽  
...  

The MAL (MAL/VIP17) proteolipid is a nonglycosylated integral membrane protein expressed in a restricted pattern of cell types, including T lymphocytes, myelin-forming cells, and polarized epithelial cells. Transport of the influenza virus hemagglutinin (HA) to the apical surface of epithelial Madin-Darby canine kidney (MDCK) cells appears to be mediated by a pathway involving glycolipid- and cholesterol- enriched membranes (GEMs). In MDCK cells, MAL has been proposed previously as being an element of the protein machinery for the GEM-dependent apical transport pathway. Using an antisense oligonucleotide-based strategy and a newly generated monoclonal antibody to canine MAL, herein we have approached the effect of MAL depletion on HA transport in MDCK cells. We have found that MAL depletion diminishes the presence of HA in GEMs, reduces the rate of HA transport to the cell surface, inhibits the delivery of HA to the apical surface, and produces partial missorting of HA to the basolateral membrane. These effects were corrected by ectopic expression of MAL in MDCK cells whose endogenous MAL protein was depleted. Our results indicate that MAL is necessary for both normal apical transport and accurate sorting of HA.


2001 ◽  
Vol 114 (7) ◽  
pp. 1331-1341 ◽  
Author(s):  
A.K. Criss ◽  
D.M. Ahlgren ◽  
T.S. Jou ◽  
B.A. McCormick ◽  
J.E. Casanova

The bacterial pathogen Salmonella typhimurium colonizes its animal hosts by inducing its internalization into intestinal epithelial cells. This process requires reorganization of the actin cytoskeleton of the apical plasma membrane into elaborate membrane ruffles that engulf the bacteria. Members of the Ρ family of small GTPases are critical regulators of actin structure, and in nonpolarized cells, the GTPase Cdc42 has been shown to modulate Salmonella entry. Because the actin architecture of epithelial cells is organized differently from that of nonpolarized cells, we examined the role of two ‘Rgr; family GTPases, Cdc42 and Rac1, in invasion of polarized monolayers of MDCK cells by S. typhimurium. Surprisingly, we found that endogenous Rac1, but not Cdc42, was activated during bacterial entry at the apical pole, and that this activation required the bacterial effector protein SopE. Furthermore, expression of dominant inhibitory Rac1 but not Cdc42 significantly inhibited apical internalization of Salmonella, indicating that Rac1 activation is integral to the bacterial entry process. In contrast, during basolateral internalization, both Cdc42 and Rac1 were activated; however, neither GTPase was required for entry. These findings, which differ significantly from previous observations in nonpolarized cells, indicate that the host cell signaling pathways activated by bacterial pathogens may vary with cell type, and in epithelial tissues may further differ between plasma membrane domains.


Cells ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 1057
Author(s):  
Richard Bouley ◽  
Naofumi Yui ◽  
Abby Terlouw ◽  
Pui W. Cheung ◽  
Dennis Brown

We previously showed that in polarized Madin–Darby canine kidney (MDCK) cells, aquaporin-2 (AQP2) is continuously targeted to the basolateral plasma membrane from which it is rapidly retrieved by clathrin-mediated endocytosis. It then undertakes microtubule-dependent transcytosis toward the apical plasma membrane. In this study, we found that treatment with chlorpromazine (CPZ, an inhibitor of clathrin-mediated endocytosis) results in AQP2 accumulation in the basolateral, but not the apical plasma membrane of epithelial cells. In MDCK cells, both AQP2 and clathrin were concentrated in the basolateral plasma membrane after CPZ treatment (100 µM for 15 min), and endocytosis was reduced. Then, using rhodamine phalloidin staining, we found that basolateral, but not apical, F-actin was selectively reduced by CPZ treatment. After incubation of rat kidney slices in situ with CPZ (200 µM for 15 min), basolateral AQP2 and clathrin were increased in principal cells, which simultaneously showed a significant decrease of basolateral compared to apical F-actin staining. These results indicate that clathrin-dependent transcytosis of AQP2 is an essential part of its trafficking pathway in renal epithelial cells and that this process can be inhibited by selectively depolymerizing the basolateral actin pool using CPZ.


Author(s):  
Greg Martin ◽  
Rohit Cariappa ◽  
Ann L. Hubbard

The plasma membrane of polarized epithelial cells is composed of two structurally and functionally distinct domains -- the apical and basolateral -- that also differ in molecular composition. The routes followed by integral membrane proteins from their site of synthesis to their site of function varies between different kinds of epithelia. Madin-Darby canine kidney (MDCK) cells deliver plasma membrane proteins directly to the correct domain, while polarized hepatocytes deliver all newly synthesized plasma membrane proteins initially to the basolateral membrane, then retrieve and redirect the apical membrane proteins. We are studying the targeting signals and delivery routes of DPPIV, a single transmembrane protein whose destination is the apical domain in polarized epithelial cells.DPPIV transfected into MDCK cells is delivered to the basolateral plasma membrane after long (13hr) treatment with Brefeldin A (BFA). After BFA’s removal these molecules are retrieved from the basolateral membrane and transcytosed to the apical plasma membrane. This protocol provides a useful model for studies of the indirect route of protein sorting in polarized epithelial cells, since DPPIV at the basolateral surface can be labeled with specific antibody and then subsequently followed in living cells.


2004 ◽  
Vol 286 (2) ◽  
pp. F363-F369 ◽  
Author(s):  
Sertac N. Kip ◽  
Emanuel E. Strehler

Plasma membrane Ca2+-ATPases (PMCAs) are a ubiquitous system for the expulsion of Ca2+ from eukaryotic cells. In tight monolayers of polarized Madin-Darby canine kidney (MDCK) cells representing a distal kidney tubule model, PMCAs are responsible for about one-third of the vectorial Ca2+ transport under resting conditions, with the remainder being provided by the Na+/Ca2+ exchanger. Vitamin D3 (VitD) is known to increase PMCA expression and activity in Ca2+-transporting tissues such as the intestine, as well as in osteoblasts and Madin-Darby bovine kidney epithelial cells. We found that VitD upregulated the expression of the PMCAs (mainly PMCA4b) in MDCK cell lysates at the RNA and protein level in a time- and dose-dependent manner. Interestingly, VitD caused a decrease of the PMCAs in the apical plasma membrane fraction and a concomitant increase of the pumps in the basolateral membrane. Functional studies demonstrated that transcellular 45Ca2+ flux from the apical-to-basolateral compartment was significantly enhanced by VitD. These findings demonstrate that VitD is a positive regulator of the PMCAs in MDCK epithelial cells. The correlation of decreased apical/increased basolateral expression of the PMCAs with an increase in transcellular Ca2+ flux from the apical (urine) toward the basolateral (blood) compartment indicates the physiological relevance of VitD function in kidney tubular Ca2+ reabsorption.


1989 ◽  
Vol 109 (1) ◽  
pp. 163-177 ◽  
Author(s):  
M Pasdar ◽  
W J Nelson

Desmosomes are composed of two morphologically and biochemically distinct domains, a cytoplasmic plaque and membrane core. We have initiated a study of the synthesis and assembly of these domains in Madin-Darby canine kidney (MDCK) epithelial cells to understand the mechanisms involved in the formation of desmosomes. Previously, we reported the kinetics of assembly of two components of the cytoplasmic plaque domain, Desmoplakin I/II (Pasdar, M., and W. J. Nelson. 1988. J. Cell Biol. 106:677-685 and 106:687-699. We have now extended this analysis to include a major glycoprotein component of the membrane core domain, Desmoglein I (DGI; Mr = 150,000). Using metabolic labeling and inhibitors of glycoprotein processing and intracellular transport, we show that DGI biosynthesis is a sequential process with defined stages. In the absence of cell-cell contact, DGI enters a Triton X-100 soluble pool and is core glycosylated. The soluble DGI is then transported to the Golgi complex where it is first complex glycosylated and then titrated into an insoluble pool. The insoluble pool of DGI is subsequently transported to the plasma membrane and is degraded rapidly (t1/2 less than 4 h). Although this biosynthetic pathway occurs independently of cell-cell contact, induction of cell-cell contact results in dramatic increases in the efficiency and rate of titration of DGI from the soluble to the insoluble pool, and its transport to the plasma membrane where DGI becomes metabolically stable (t1/2 greater than 24 h). Taken together with our previous study of DPI/II, we conclude that newly synthesized components of the cytoplasmic plaque and membrane core domains are processed and assembled with different kinetics indicating that, at least initially, each domain is assembled separately in the cell. However, upon induction of cell-cell contact there is a rapid titration of both components into an insoluble and metabolically stable pool at the plasma membrane that is concurrent with desmosome assembly.


2000 ◽  
Vol 279 (3) ◽  
pp. F417-F425 ◽  
Author(s):  
Jürgen Reinhardt ◽  
Alexander V. Grishin ◽  
Hans Oberleithner ◽  
Michael J. Caplan

The human H+-K+-ATPase, ATP1AL1, belongs to the subgroup of nongastric, K+-transporting ATPases. In concert with the structurally related gastric H+-K+-ATPase, it plays a major role in K+ reabsorption in various tissues, including colon and kidney. Physiological and immunocytochemical data suggest that the functional heteromeric ion pumps are usually found in the apical plasma membranes of renal epithelial cells. However, the low expression levels of characteristic nongastric ion pumps makes it difficult to verify their spatial distribution in vivo. To investigate the sorting behavior of ATP1AL1, we expressed this pump by stable transfection in MDCK and LLC-PK1 renal epithelial cell lines. Stable interaction of ATP1AL1 with either the endogenous Na+-K+-ATPase β-subunit or the gastric H+-K+-ATPase β-subunit was tested by confocal immunofluorescence microscopy and surface biotinylation. In cells transfected with ATP1AL1 alone, the α-subunit accumulated intracellularly, consistent with its inability to assemble and travel to the plasma membrane with the endogenous Na+-K+-ATPase β-subunit. Cotransfection of ATP1AL1 with the gastric H+-K+-ATPase β-subunit resulted in plasma membrane localization of both pump subunits. In cotransfected MDCK cells the heteromeric ion pump was predominantly polarized to the apical plasma membrane. Functional expression of ATP1AL1 was confirmed by 86Rb+uptake measurements. In contrast, cotransfected LLC-PK1cells accumulate ATP1AL1 at the lateral membrane. The distinct polarization of ATP1AL1 indicates that the α-subunit encodes sorting information that is differently interpreted by cell type-specific sorting mechanisms.


1984 ◽  
Vol 98 (4) ◽  
pp. 1304-1319 ◽  
Author(s):  
M J Rindler ◽  
I E Ivanov ◽  
H Plesken ◽  
E Rodriguez-Boulan ◽  
D D Sabatini

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.


1984 ◽  
Vol 65 (1) ◽  
pp. 209-221
Author(s):  
J.M. Edwardson

The role of the Golgi complex in the intracellular transport of influenza virus haemagglutinin in infected MDCK cell monolayers has been investigated using monensin, a carboxylic ionophore known to disrupt the functioning of this organelle in other cell types. In untreated cells metabolically labelled 5 h post-infection with [35S]methionine haemagglutinin was first seen in core glycosylated form, which was sensitive to the enzyme endo-beta-N-acetylglucosaminidase H (endo H). After approximately 20 min this form was converted into a terminally glycosylated, endo H-resistant form. In the presence of monensin core glycosylation of haemagglutinin was not affected, but terminal glycosylation was interrupted. Two new forms of haemagglutinin were observed, both of which were smaller than the core glycosylated form. Of these, the larger was endo H-sensitive while the smaller was endo H-resistant. These new (and uncharacterized) forms of haemagglutinin are likely to be intermediates in the normal process of terminal glycosylation, which are revealed as a result of the inhibition by monensin of the transport of haemagglutinin through the stack of Golgi cisternae. In untreated cells 85% of the pulse-labelled haemagglutinin had reached the plasma membrane after 90 min of chase, as revealed by its sensitivity to externally applied trypsin. In monensin-treated cells, on the other hand, only 55% of the haemagglutinin had reached the plasma membrane after 90 min of chase, while 94% had arrived there after 180 min of chase. At 5 h post-infection the density of envelope proteins detected at the apical surface of the monolayer by immunofluorescence microscopy was greatly reduced by monensin treatment. Budding of virions from the apical surface of the monolayer at 4 and 7 h post-infection was also reduced, and the normal Golgi complexes were replaced by distended vacuoles that appeared to contain poorly preserved virions.


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