scholarly journals Monensin and FCCP inhibit the intracellular transport of alphavirus membrane glycoproteins

1980 ◽  
Vol 87 (3) ◽  
pp. 783-791 ◽  
Author(s):  
L Kaariainen ◽  
K Hashimoto ◽  
J Saraste ◽  
I Virtanen ◽  
K Penttinen

Temperature-sensitive mutants of semliki forest virus (SFV) and sindbis virus (SIN) were used to study the intracellular transport of virus membrane glycoproteins in infected chicken embryo fibroblasts. When antisera against purified glycoproteins and (125)I- labeled protein A from staphylococcus aureus were used only small amounts of virus glycoproteins were detected at the surface of SFV ts-1 and SIN Ts-10 infected cells incubated at the restrictive temperature (39 degrees C). When the mutant-infected cells were shifted to the permissive temperature (28 degrees C), in the presence of cycloheximide, increasing amounts of virus glycoproteins appeared at the cell surface from 20 to 80 min after the shift. Both monensin (10muM) and carbonylcyanide-p- trifluoromethoxyphenylhydrazone (FCCP; 10-20 muM) inhibited the appearance of virus membrane glycoproteins at the cell surface. Vinblastine sulfate (10 μg/ml) inhibited the transport by approximately 50 percent, whereas cytochalasin B (1 μg/ml) had only a marginal effect. Intracellular distribution of virus glycoproteins in the mutant-infected cells was visualized in double-fluorescence studies using lectins as markers for endoplasmic reticulum and Golgi apparatus. At 39 degrees C, the virus membrane glycoproteins were located at the endoplasmic reticulum, whereas after shift to 28 degrees C, a bright juxtanuclear reticular fluorescence was seen in the location of the Golgi apparatus. In the presence of monensin, the virus glycoproteins could migrate to the Golgi apparatus, although transport to the cell surface did not take place. When the shift was carried out in the presence of FCCP, negligible fluorescence was seen in the Golgi apparatus and the glycoproteins apparently remained in the rough endoplasmic reticulum. A rapid inhibition in the accumulation of virus glycoproteins at the cell surface was obtained when FCCP was added during the active transport period, whereas with monensin there was a delay of approximately 10 min. These results suggest a similar intracellular pathway in the maturation of both plasma membrane and secretory glycoproteins.

1984 ◽  
Vol 68 (1) ◽  
pp. 83-94
Author(s):  
C.J. Flickinger

The production, transport, and disposition of material labelled with [3H]mannose were studied in microsurgically enucleated and control amoebae. Cells were injected with the precursor and samples were prepared for electron-microscope radioautography at intervals, up to 24 h later. Control cells showed heavy labelling of the rough endoplasmic reticulum and the Golgi apparatus at early intervals after injection. Later, labelling of groups of small vesicles increased, and the percentage of grains over the cell surface peaked 12 h after administration of the precursor. Two major changes were detected in enucleate amoebae. First, the kinetics of labelling of cell organelles with [3H]mannose were altered in the absence of the nucleus. The Golgi apparatus and cell surface both displayed maximal labelling at later intervals in enucleates, and the percentage of grains over the rough endoplasmic reticulum varied less with time in enucleated than in control cells. Second, the distribution of radioactivity was altered. A greater percentage of grains was associated with lysosomes in enucleates than in control cells. The change in the kinetics of labelling of the endoplasmic reticulum, Golgi apparatus and cell surface indicates that intracellular transport of surface material was slower in the absence of the nucleus. It is suggested that this is related to the decreased motility of enucleate cells.


1985 ◽  
Vol 101 (3) ◽  
pp. 725-734 ◽  
Author(s):  
D B Williams ◽  
S J Swiedler ◽  
G W Hart

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.


1981 ◽  
Vol 29 (9) ◽  
pp. 1080-1087 ◽  
Author(s):  
S Tokumitsu ◽  
K Tokumitsu ◽  
W H Fishman

The ultrastructural localization of alkaline phosphatase has been examined in cells of a HeLa subline (TCRC-1) that are monophenotypic for Regan isoenzyme expression. Enzyme activity was demonstrated at the cell surface plasma membrane and in certain lysosomes as revealed by the lead citrate method. The regular direct immunoperoxidase procedure utilizing antibodies in IgG or Fab' form showed the same distribution patterns of alkaline phosphatase. However, when the cell surface antigen was blocked in advance with specific unlabeled antibodies and direct immunocytochemistry performed in the presence of saponin, intracellular alkaline phosphatase antigen was observed in the perinuclear space, endoplasmic reticulum, and Golgi apparatus. The results appeared to be concordant with the current concept that membrane glycoproteins are formed in the endoplasmic reticulum, modified in the Golgi apparatus and then transported to the cell surface. Intracellular alkaline phosphatase was observed predominantly in some cell populations especially mitotic cells, suggesting that the enzyme protein was synthesized in and around the mitotic phase. Accordingly, this technique of differential membrane immunocytochemistry appears to provide an opportunity to follow ectopic gene expression as a function of cell cycle and enzyme induction.


1992 ◽  
Vol 102 (3) ◽  
pp. 505-513 ◽  
Author(s):  
E. Kuismanen ◽  
J. Jantti ◽  
V. Makiranta ◽  
M. Sariola

The effect of caffeine on the intracellular transport of Semliki Forest virus (SFV) membrane glycoproteins was studied in baby hamster kidney (BHK) cells. The movement of the proteins was affected at two steps in the exocytic pathway. The exit of the proteins from the endoplasmic reticulum (ER) was inhibited by 10 mM caffeine at 20 degrees C, a temperature that normally allows transport to the Golgi complex. At higher temperatures (28 degrees C and 37 degrees C) in the presence of 10 mM caffeine exit from the ER occurred, but the proteins accumulated at intracellular membrane elements. Immunofluorescence localization, endoglycosidase-H analysis, and analysis of the proteolytical cleavage of the p62 precursor protein suggested that transport in the presence of 10 mM caffeine was arrested at the membranes between the trans-Golgi and the plasma membrane.


1985 ◽  
Vol 100 (3) ◽  
pp. 704-714 ◽  
Author(s):  
C Doyle ◽  
M G Roth ◽  
J Sambrook ◽  
M J Gething

Mutations have been introduced into the cloned DNA sequences coding for influenza virus hemagglutinin (HA), and the resulting mutant genes have been expressed in simian cells by the use of SV40-HA recombinant viral vectors. In this study we analyzed the effect of specific alterations in the cytoplasmic domain of the HA molecule on its rate of biosynthesis and transport, cellular localization, and biological activity. Several of the mutants displayed abnormalities in the pathway of transport from the endoplasmic reticulum to the cell surface. One mutant HA remained within the endoplasmic reticulum; others were delayed in reaching the Golgi apparatus after core glycosylation had been completed in the endoplasmic reticulum, but then progressed at a normal rate from the Golgi apparatus to the cell surface; another was delayed in transport from the Golgi apparatus to the plasma membrane. However, two mutants were indistinguishable from wild-type HA in their rate of movement from the endoplasmic reticulum through the Golgi apparatus to the cell surface. We conclude that changes in the cytoplasmic domain can powerfully influence the rate of intracellular transport and the efficiency with which HA reaches the cell surface. Nevertheless, absolute conservation of this region of the molecule is not required for maturation and efficient expression of a biologically active HA on the surface of infected cells.


1988 ◽  
Vol 106 (6) ◽  
pp. 1853-1861 ◽  
Author(s):  
B Stieger ◽  
K Matter ◽  
B Baur ◽  
K Bucher ◽  
M Höchli ◽  
...  

Novel subcellular fractionation procedures and pulse-chase techniques were used to study the intracellular transport of the microvillar membrane hydrolases sucrase-isomaltase and dipeptidylpeptidase IV in the differentiated colon adenocarcinoma cell line Caco-2. The overall rate of transport to the cell surface was two fold faster for dipeptidylpeptidase IV than for sucrase-isomaltase, while no significant differences were observed in transport rates from the site of complex glycosylation to the brush border. The delayed arrival of sucrase-isomaltase in the compartment where complex glycosylation occurs was only in part due to exit from the endoplasmic reticulum. A major slow-down could be ascribed to maturation in and transit of this enzyme through the Golgi apparatus. These results suggest that the observed asynchronism is due to more than one rate-limiting step along the rough endoplasmic reticulum to trans-Golgi pathway.


1989 ◽  
Vol 92 (4) ◽  
pp. 633-642
Author(s):  
J.K. Burkhardt ◽  
Y. Argon

The appearance of newly synthesized glycoprotein (G) of vesicular stomatitis virus at the surface of infected BHK cells is inhibited reversibly by treatment with carbonylcyanide m-chlorophenylhydrazone (CCCP). Under the conditions used, CCCP treatment depleted the cellular ATP levels by 40–60%, consistent with inhibition of transport at energy-requiring stages. The G protein that accumulates in cells treated with CCCP is heterogeneous. Most of it is larger than the newly synthesized G protein, is acylated with palmitic acid, and is resistant to endoglycosidase H (Endo H). Most of the arrested G protein is also sensitive to digestion with neuraminidase, indicating that it has undergone at least partial sialylation. A minority of G protein accumulates under these conditions in a less-mature form, suggesting its inability to reach the mid-Golgi compartment. The oligosaccharides of this G protein are Endo-H-sensitive and seem to be partly trimmed. Whereas sialylated G protein was arrested intracellularly, fucose-labelled G protein was able to complete its transport to the cell surface, indicating that a late CCCP-sensitive step separates sialylation from fucosylation. These post-translational modifications indicate that G protein can be transported as far as the trans-Golgi in the presence of CCCP and is not merely arrested in the endoplasmic reticulum.


2004 ◽  
Vol 78 (8) ◽  
pp. 3880-3888 ◽  
Author(s):  
Ana M. Falcón ◽  
Rosa M. Marión ◽  
Thomas Zürcher ◽  
Paulino Gómez ◽  
Agustín Portela ◽  
...  

ABSTRACT Influenza A virus mutants expressing C-terminally deleted forms of the NS1 protein (NS1-81 and NS1-110) were generated by plasmid rescue. These viruses were temperature sensitive and showed a small plaque size at the permissive temperature. The accumulation of virion RNA in mutant virus-infected cells was reduced at the restrictive temperature, while the accumulation of cRNA or mRNA was not affected, indicating that the NS1 protein is involved in the control of transcription versus replication processes in the infection. The synthesis and accumulation of late virus proteins were reduced in NS1-81 mutant-infected cells at the permissive temperature and were essentially abolished for both viruses at the restrictive temperature, while synthesis and accumulation of nucleoprotein (NP) were unaffected. Probably as a consequence, the nucleocytoplasmic export of virus NP was strongly inhibited at the restrictive temperature. These results indicate that the NS1 protein is essential for nuclear and cytoplasmic steps during the virus cycle.


1985 ◽  
Vol 101 (5) ◽  
pp. 1733-1740 ◽  
Author(s):  
A Yamamoto ◽  
R Masaki ◽  
Y Tashiro

The Golgi apparatus mediates intracellular transport of not only secretory and lysosomal proteins but also membrane proteins. As a typical marker membrane protein for endoplasmic reticulum (ER) of rat hepatocytes, we have selected phenobarbital (PB)-inducible cytochrome P-450 (P-450[PB]) and investigated whether P-450(PB) is transported to the Golgi apparatus or not by combining biochemical and quantitative ferritin immunoelectron microscopic techniques. We found that P-450(PB) was not detectable on the membrane of Golgi cisternae either when P-450 was maximally induced by phenobarbital treatment or when P-450 content in the microsomes rapidly decreased after cessation of the treatment. The P-450 detected biochemically in the Golgi subcellular fraction can be explained by the contamination of the microsomal vesicles derived from fragmented ER membranes to the Golgi fraction. We conclude that when the transfer vesicles are formed by budding on the transitional elements of ER, P-450 is completely excluded from such regions and is not transported to the Golgi apparatus, and only the membrane proteins destined for the Golgi apparatus, plasma membranes, or lysosomes are selectively collected and transported.


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