scholarly journals Polarized Budding of Measles Virus Is Not Determined by Viral Surface Glycoproteins

1998 ◽  
Vol 72 (6) ◽  
pp. 5276-5278 ◽  
Author(s):  
A. Maisner ◽  
H.-D. Klenk ◽  
G. Herrler

ABSTRACT For viruses that mature by a budding process, the envelope glycoproteins are considered the major determinants for the site of virus release from polarized epithelial cells. Viruses are usually released from that membrane domain where the viral surface glycoproteins are transported to. We here report that measles virus has developed a different maturation strategy. Measles virus was found to be released from the apical membrane domain of polarized epithelial cells, though the surface glycoproteins H and F were transported in a nonpolarized fashion and to the basolateral membrane domain, respectively.

2001 ◽  
Vol 75 (3) ◽  
pp. 1274-1283 ◽  
Author(s):  
Christian Sänger ◽  
Elke Mühlberger ◽  
Elena Ryabchikova ◽  
Larissa Kolesnikova ◽  
Hans-Dieter Klenk ◽  
...  

ABSTRACT Marburg virus, a filovirus, causes severe hemorrhagic fever with hitherto poorly understood molecular pathogenesis. We have investigated here the vectorial transport of the surface protein GP of Marburg virus in polarized epithelial cells. To this end, we established an MDCKII cell line that was able to express GP permanently (MDCK-GP). The functional integrity of GP expressed in these cells was analyzed using vesicular stomatitis virus pseudotypes. Further experiments revealed that GP is transported in MDCK-GP cells mainly to the apical membrane and is released exclusively into the culture medium facing the apical membrane. When MDCKII cells were infected with Marburg virus, the majority of GP was also transported to the apical membrane, suggesting that the protein contains an autonomous apical transport signal. Release of infectious progeny virions, however, took place exclusively at the basolateral membrane of the cells. Thus, vectorial budding of Marburg virus is presumably determined by factors other than the surface protein.


2015 ◽  
Vol 89 (23) ◽  
pp. 12026-12034 ◽  
Author(s):  
Hiroshi Katoh ◽  
Yuichiro Nakatsu ◽  
Toru Kubota ◽  
Masafumi Sakata ◽  
Makoto Takeda ◽  
...  

ABSTRACTMumps virus (MuV) is an airborne virus that causes a systemic infection in patients.In vivo, the epithelium is a major replication site of MuV, and thus, the mode of MuV infection of epithelial cells is a subject of interest. Our data in the present study showed that MuV entered polarized epithelial cells via both the apical and basolateral surfaces, while progeny viruses were predominantly released from the apical surface. In polarized cells, intracellular transport of viral ribonucleoprotein (vRNP) complexes was dependent on Rab11-positive endosomes, and vRNP complexes were transported to the apical membrane. Expression of a dominant negative form of Rab11 (Rab11S25N) reduced the progeny virus release in polarized cells but not in nonpolarized cells. Although in this way these effects were correlated with cell polarity, Rab11S25N did not modulate the direction of virus release from the apical surface. Therefore, our data suggested that Rab11 is not a regulator of selective apical release of MuV, although it acts as an activator of virus release from polarized epithelial cells. In addition, our data and previous studies on Sendai virus, respiratory syncytial virus, and measles virus suggested that selective apical release from epithelial cells is used by many paramyxoviruses, even though they cause either a systemic infection or a local respiratory infection.IMPORTANCEMumps virus (MuV) is the etiological agent of mumps and causes a systemic infection. However, the precise mechanism by which MuV breaks through the epithelial barriers and achieves a systemic infection remains unclear. In the present study, we show that the entry of MuV is bipolar, while the release is predominantly from the apical surface in polarized epithelial cells. In addition, the release of progeny virus was facilitated by a Rab11-positive recycling endosome and microtubule network. Our data provide important insights into the mechanism of transmission and pathogenesis of MuV.


1998 ◽  
Vol 9 (3) ◽  
pp. 685-699 ◽  
Author(s):  
Kent K. Grindstaff ◽  
Robert L. Bacallao ◽  
W. James Nelson

In nonpolarized epithelial cells, microtubules originate from a broad perinuclear region coincident with the distribution of the Golgi complex and extend outward to the cell periphery (perinuclear [PN] organization). During development of epithelial cell polarity, microtubules reorganize to form long cortical filaments parallel to the lateral membrane, a meshwork of randomly oriented short filaments beneath the apical membrane, and short filaments at the base of the cell; the Golgi becomes localized above the nucleus in the subapical membrane cytoplasm (apiconuclear [AN] organization). The AN-type organization of microtubules is thought to be specialized in polarized epithelial cells to facilitate vesicle trafficking between the trans-Golgi Network (TGN) and the plasma membrane. We describe two clones of MDCK cells, which have different microtubule distributions: clone II/G cells, which gradually reorganize a PN-type distribution of microtubules and the Golgi complex to an AN-type during development of polarity, and clone II/J cells which maintain a PN-type organization. Both cell clones, however, exhibit identical steady-state polarity of apical and basolateral proteins. During development of cell surface polarity, both clones rapidly establish direct targeting pathways for newly synthesized gp80 and gp135/170, and E-cadherin between the TGN and apical and basolateral membrane, respectively; this occurs before development of the AN-type microtubule/Golgi organization in clone II/G cells. Exposure of both clone II/G and II/J cells to low temperature and nocodazole disrupts >99% of microtubules, resulting in: 1) 25–50% decrease in delivery of newly synthesized gp135/170 and E-cadherin to the apical and basolateral membrane, respectively, in both clone II/G and II/J cells, but with little or no missorting to the opposite membrane domain during all stages of polarity development; 2) ∼40% decrease in delivery of newly synthesized gp80 to the apical membrane with significant missorting to the basolateral membrane in newly established cultures of clone II/G and II/J cells; and 3) variable and nonspecific delivery of newly synthesized gp80 to both membrane domains in fully polarized cultures. These results define several classes of proteins that differ in their dependence on intact microtubules for efficient and specific targeting between the Golgi and plasma membrane domains.


2002 ◽  
Vol 282 (2) ◽  
pp. F324-F329 ◽  
Author(s):  
János Peti-Peterdi ◽  
Zsuzsa Bebok ◽  
Jean-Yves Lapointe ◽  
P. Darwin Bell

Na-K-ATPase is the nearly ubiquitous enzyme that maintains low-Na+, high-K+concentrations in cells by actively extruding Na+ in exchange for K+. The prevailing paradigm in polarized absorbing epithelial cells, including renal nephron segments and intestine, has been that Na-K-ATPase is restricted to the basolateral membrane domain, where it plays a prominent role in Na+absorption. We have found, however, that macula densa (MD) cells lack functionally and immunologically detectable amounts of Na-K-ATPase protein. In fact, these cells appear to regulate their cytosolic [Na+] via another member of the P-type ATPase family, the colonic form of H-K-ATPase, which is located at the apical membrane in these cells. We now report that this constitutively expressed apical MD colonic H-K-ATPase can function as a Na(H)-K-ATPase and regulate cytosolic [Na+] in a novel manner. This apical Na+-recycling mechanism may be important as part of the sensor function of MD cells and represents a new paradigm in cell [Na+] regulation.


1982 ◽  
Vol 243 (3) ◽  
pp. C140-C145 ◽  
Author(s):  
A. C. Ericson ◽  
K. R. Spring

NaCl entry into Necturus maculosus gallbladder epithelial cells was studied by determination of the rate of fluid movement into the cell when the Na+-K+-ATPase was inhibited by 10(-4) M ouabain in the serosal bathing solution. The cell swelling was due to continuing entrance of NaCl into the cell across the apical membrane, which increased the solute content of the cell; the resultant rise in cell osmolality induced water flow and cell swelling. The rate of swelling was 4.3% of the cell volume per minute, equivalent to a volume flow across the apical membrane of 1.44 x 10(-6) cm/s, similar in magnitude to the normal rate of fluid absorption by the gallbladder. We determined the mechanism of NaCl entry by varying the ionic composition of the mucosal bath; when most of the mucosal Na+ or Cl- was replaced, cell volume did not increase during pump inhibition. The rate of NaCl entry was a saturable function of Na+ or Cl- in the mucosal bathing solution with K1/2 values of 26.6 mM for Na+ and 19.5 mM for Cl-. The mode of NaCl entry was probably not the parallel operation of Na+-H+ and Cl(-)-HCO-3 exchangers because of the lack of effect of bicarbonate removal or of the inhibitors amiloride and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid. NaCl entry was reversibly inhibited by bumetanide in the mucosal bathing solution. Transepithelial NaCl and water absorption is the result of the coupled, carrier-mediated movement of NaCl into the cell across the apical membrane and the active extrusion of Na+ by the Na+-K+-ATPase in the basolateral membrane.


1999 ◽  
Vol 276 (1) ◽  
pp. C91-C101 ◽  
Author(s):  
Kurt Amsler ◽  
Scott K. Kuwada

Signal transduction from receptors is mediated by the interaction of activated receptors with proximate downstream signaling proteins. In polarized epithelial cells, the membrane is divided into subdomains: the apical and basolateral membranes. Membrane receptors may be present in one or both subdomains. Using a combination of immunoprecipitation and Western blot analyses, we tested the hypothesis that a tyrosine kinase growth factor receptor, epidermal growth factor receptor (EGFR), interacts with distinct signaling proteins when present at the apical vs. basolateral membrane of a polarized renal epithelial cell. We report here that tyrosine phosphorylation of phospholipase C-γ (PLC-γ) was induced only when basolateral EGFR was activated. In contrast, tyrosine phosphorylation of several other signaling proteins was increased by activation of receptor at either surface. All signaling proteins were distributed diffusely throughout the cytoplasm; however, PLC-γ protein also displayed a concentration at lateral cell borders. These results demonstrate that in polarized epithelial cells the array of signaling pathways initiated by activation of a membrane receptor is defined, at least in part, by the membrane location of the receptor.


2005 ◽  
Vol 289 (1) ◽  
pp. F83-F89 ◽  
Author(s):  
Joshua D. Zeidel ◽  
John C. Mathai ◽  
John D. Campbell ◽  
Wily G. Ruiz ◽  
Gerard L. Apodaca ◽  
...  

Elasmobranchs such as the dogfish shark Squalus acanthius achieve osmotic homeostasis by maintaining urea concentrations in the 300- to 400-mM range, thus offsetting to some degree ambient marine osmolalities of 900–1,000 mosmol/kgH2O. These creatures also maintain salt balance without losing urea by secreting a NaCl-rich (500 mM) and urea-poor (18 mM) fluid from the rectal gland that is isotonic with the plasma. The composition of the rectal gland fluid suggests that its epithelial cells are permeable to water and not to urea. Because previous work showed that lipid bilayers that permit water flux do not block flux of urea, we reasoned that the plasma membranes of rectal gland epithelial cells must either have aquaporin water channels or must have some selective barrier to urea flux. We therefore isolated apical and basolateral membranes from shark rectal glands and determined their permeabilities to water and urea. Apical membrane fractions were markedly enriched for Na-K-2Cl cotransporter, whereas basolateral membrane fractions were enriched for Na-K-ATPase. Basolateral membrane osmotic water permeability (Pf) averaged 4.3 ± 1.3 × 10−3 cm/s, whereas urea permeability averaged 4.2 ± 0.8 × 10−7 cm/s. The activation energy for water flow averaged 16.4 kcal/mol. Apical membrane Pf averaged 7.5 ± 1.6 × 10−4 cm/s, and urea permeability averaged 2.2 ± 0.4 × 10−7 cm/s, with an average activation energy for water flow of 18.6 kcal/mol. The relatively low water permeabilities and high activation energies argue strongly against water flux via aquaporins. Comparison of membrane water and urea permeabilities with those of artificial liposomes and other isolated biological membranes indicates that the basolateral membrane urea permeability is fivefold lower than would be anticipated for its water permeability. These results indicate that the rectal gland maintains a selective barrier to urea in its basolateral membranes.


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