scholarly journals Quality control in the endoplasmic reticulum: folding and misfolding of vesicular stomatitis virus G protein in cells and in vitro.

1990 ◽  
Vol 111 (3) ◽  
pp. 857-866 ◽  
Author(s):  
A M de Silva ◽  
W E Balch ◽  
A Helenius
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Disulfide Bonds ◽  
Secretory Pathway ◽  
Free System ◽  
Virus Particles ◽  
Golgi Compartment ◽  
A Cell ◽  
Vesicular Stomatitis

Parallel experiments in living cells and in vitro were undertaken to characterize the mechanism by which misfolded and unassembled glycoproteins are retained in the ER. A thermoreversible folding mutant of vesicular stomatitis virus (VSV) G protein called ts045 was analyzed. At 39 degrees C, newly synthesized G failed to fold correctly according to several criteria: intrachain disulfide bonds were incomplete; the B2 epitope was absent; and the protein was associated with immunoglobulin heavy chain binding protein (BiP), a heat shock-related, ER protein. When the temperature was lowered to 32 degrees C, these properties were reversed, and the protein was transported to the cell surface. Upon the shift up from 32 degrees C back to 39 degrees C, G protein in the ER returned to the misfolded form and was retained, while the protein that had reached a pre-Golgi compartment or beyond was thermostable and remained transport competent. The misfolding reaction could be reconstituted in a cell free system using ts045 virus particles and protein extracts from microsomes. Taken together, the results showed that ER is unique among the organelles of the secretory pathway in containing specific factors capable of misfolding G protein at the nonpermissive temperature and thus participating in its retention.

scholarly journals Reconstitution of transport of vesicular stomatitis virus G protein from the endoplasmic reticulum to the Golgi complex using a cell-free system.

1987 ◽  
Vol 104 (3) ◽  
pp. 749-760 ◽  
Author(s):  
W E Balch ◽  
K R Wagner ◽  
D S Keller
Keyword(s):  
Endoplasmic Reticulum ◽  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Golgi Complex ◽  
Free System ◽  
A Cell ◽  
Vesicular Stomatitis ◽  
High Mannose

Transport of the vesicular stomatitis virus-encoded glycoprotein (G protein) between the endoplasmic reticulum (ER) and the cis Golgi compartment has been reconstituted in a cell-free system. Transfer is measured by the processing of the high mannose (man GlcNAc2) ER form of G protein to the man5GlcNAc5 form by the cis Golgi enzyme alpha-mannosidase I. G protein is rapidly and efficiently transported to the Golgi complex by a process resembling that observed in vivo. G protein is trimmed from the high mannose form to the man5GlcNAc2 form without the appearance of the intermediate man GlcNAc2 oligosaccharide species, as is observed in vivo. G protein is found in a sealed membrane-bound compartment before and after incubation. Processing in vitro is sensitive to detergent, and the Golgi alpha-mannosidase I inhibitor 1-deoxymannorjirimycin. Transport between the ER and Golgi complex in vitro requires the addition of a high speed supernatant (cytosol) of cell homogenates, and requires energy in the form of ATP. Efficient reconstitution of export of protein from the ER requires the preparation of homogenates from mitotic cell populations in which the nuclear envelope, ER, and Golgi compartments have been physiologically disassembled before cell homogenization. These results suggest that the high efficiency of transport observed here may require reassembly of functional organelles in vitro.

scholarly journals In Vitro Cell-Free Conversion of Noninfectious Moloney Retrovirus Particles to an Infectious Form by the Addition of the Vesicular Stomatitis Virus Surrogate Envelope G Protein

1998 ◽  
Vol 72 (8) ◽  
pp. 6356-6361 ◽  
Author(s):  
Akihiro Abe ◽  
Shin-Tai Chen ◽  
Atsushi Miyanohara ◽  
Theodore Friedmann
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Murine Leukemia Virus ◽  
Leukemia Virus ◽  
Envelope Gene ◽  
Free System ◽  
Similar Treatment ◽  
Vesicular Stomatitis ◽  
Murine Leukemia

ABSTRACT In the absence of envelope gene expression, retrovirus packaging cell lines expressing Moloney murine leukemia virus (MLV)gag and pol genes produce large amounts of noninfectious virus-like particles that contain reverse transcriptase, processed Gag protein, and viral RNA (gag-pol RNA particles). We demonstrate that these particles can be made infectious in an in vitro, cell-free system by the addition of a surrogate envelope protein, the G spike glycoprotein of vesicular stomatitis virus (VSV-G). The appearance of infectivity is accompanied by physical association of the G protein with the immature, noninfectious virus particles. Similarly, exposure in vitro of wild-type VSV-G to a fusion-defective pseudotyped virus containing a mutant VSV-G markedly increases the infectivity of the virus to titers similar to those of conventional VSV-G pseudotyped viruses. Furthermore, similar treatment of an amphotropic murine leukemia virus significantly allows infection of BHK cells not otherwise susceptible to infection with native amphotropic virus. The partially cell-free virus maturation system reported here should be useful for studies aimed at the preparation of tissue-targeted retrovirus vectors and will also aid in studies of nucleocapsid-envelope interactions during budding and of virus assembly and virus-receptor interactions during virus uptake into infected cells. It may also represent a potentially useful step toward the eventual development of a completely cell-free retrovirus assembly system.

Intracellular transport of the glycoprotein of VSV is inhibited by CCCP at a late stage of post-translational processing

1989 ◽  
Vol 92 (4) ◽  
pp. 633-642
Author(s):  
J.K. Burkhardt ◽  
Y. Argon
Keyword(s):  
Endoplasmic Reticulum ◽  
Cell Surface ◽  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Late Stage ◽  
Intracellular Transport ◽  
Post Translational Modifications ◽  
Glycoprotein G ◽  
Golgi Compartment ◽  
Vesicular Stomatitis

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.

scholarly journals Glycoprotein-Dependent Acidification of Vesicular Stomatitis Virus Enhances Release of Matrix Protein

2009 ◽  
Vol 83 (23) ◽  
pp. 12139-12150 ◽  
Author(s):  
Chad E. Mire ◽  
Derek Dube ◽  
Sue E. Delos ◽  
Judith M. White ◽  
Michael A. Whitt
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Conformational Changes ◽  
Matrix Protein ◽  
Low Ph ◽  
M Protein ◽  
Steady Increase ◽  
Protein Dissociation ◽  
Vesicular Stomatitis

ABSTRACT To study vesicular stomatitis virus (VSV) entry and uncoating, we generated a recombinant VSV encoding a matrix (M) protein containing a C-terminal tetracysteine Lumio tag (rVSV-ML) that could be fluorescently labeled using biarsenical compounds. Quantitative confocal microscopy showed that there is a transient loss of fluorescence at early times after the initiation of endocytosis of rVSV-ML-Green (rVSV-MLG) virions, which did not occur when cells were treated with bafilomycin A1. The reduction in fluorescence occurred 5 to 10 min postentry, followed by a steady increase in fluorescence intensity from 15 to 60 min postentry. A similar loss of fluorescence was observed in vitro when virions were exposed to acidic pH. The reduction in fluorescence required G protein since “bald” ΔG-MLG particles did not show a similar loss of fluorescence at low pH. Based on the pH-dependent fluorescence properties of Lumio Green, we hypothesize that the loss of fluorescence of rVSV-MLG virions during virus entry is due to a G ectodomain-dependent acidification of the virion interior. Biochemical analysis indicated that low pH also resulted in an enhancement of M protein dissociation from partially permeabilized, but otherwise intact, wild-type virions. From these data we propose that low-pH conformational changes in G protein promote acidification of the virus interior, which facilitates the release of M from ribonucleoprotein particles during uncoating.

scholarly journals PEGylation of a Vesicular Stomatitis Virus G Pseudotyped Lentivirus Vector Prevents Inactivation in Serum

2004 ◽  
Vol 78 (2) ◽  
pp. 912-921 ◽  
Author(s):  
Maria A. Croyle ◽  
Shellie M. Callahan ◽  
Alberto Auricchio ◽  
Gregg Schumer ◽  
Klause D. Linse ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Vesicular Stomatitis Virus ◽  
Transduction Efficiency ◽  
Virus Particles ◽  
Pharmacokinetic Profiles ◽  
Vesicular Stomatitis ◽  
Poly Ethylene ◽  
Lentivirus Vectors

ABSTRACT One disadvantage of vesicular stomatitis virus G (VSV-G) pseudotyped lentivirus vectors for clinical application is inactivation of the vector by human serum complement. To prevent this, monomethoxypoly(ethylene) glycol was conjugated to a VSV-G-human immunodeficiency virus vector expressing Escherichia coli beta-galactosidase. The modification did not affect transduction efficiency in vitro and protected the vector from inactivation in complement-active human and mouse sera. Blood from mice dosed intravenously with either the unmodified or the PEGylated virus particles was assayed for active vector by a limiting-dilution assay to evaluate transduction efficiency and for p24, an indicator of the total number of virus particles present. PEGylation extended the circulation half-life of active vector by a factor of 5 and reduced the rate of vector inactivation in the serum by a factor of 1,000. Pharmacokinetic profiles for the total number of virus particles present in the circulation were unaffected by PEGylation. Modification of the vector with poly(ethylene) glycol significantly enhanced transduction efficiency in the bone marrow and in the spleen 14 days after systemic administration of the virus. These results, in concert with the pharmacokinetic profiles, indicate that PEGylation does protect the virus from inactivation in the serum and, as a result, improves the transduction efficiency of VSV-G pseudotyped lentivirus vectors in susceptible organs in vivo.

scholarly journals Selective retention of monoglucosylated high mannose oligosaccharides by a class of mutant vesicular stomatitis virus G proteins.

1989 ◽  
Vol 108 (3) ◽  
pp. 811-819 ◽  
Author(s):  
K Suh ◽  
J E Bergmann ◽  
C A Gabel
Keyword(s):  
G Protein ◽  
G Proteins ◽  
Vesicular Stomatitis Virus ◽  
Plasmid Vector ◽  
Temperature Sensitive ◽  
Permissive Temperature ◽  
Infected Cells ◽  
Vesicular Stomatitis ◽  
High Mannose

Cells infected with a temperature-sensitive mutant of vesicular stomatitis virus, ts045, or transfected with the plasmid vector pdTM12 produce mutant forms of the G protein that remain within the ER. The mutant G proteins were isolated by immunoprecipitation from cells metabolically labeled with [2-3H]mannose to facilitate analysis of the protein-linked oligosaccharides. The 3H-labeled glycopeptides recovered from the immunoprecipitated G proteins contained high mannose-type oligosaccharides. Structural analysis, however, indicated that 60-78% of the 3H-mannose-labeled oligosaccharides contained a single glucose residue and no fewer than eight mannose residues. The 3H-labeled ts045 oligosaccharides were deglucosylated and processed to complex-type units after the infected cells were returned to the permissive temperature. When shifted to the permissive temperature in the presence of a proton ionophore, the G protein oligosaccharides were deglucosylated but remained as high mannose-type units. The glucosylated state was observed, therefore, when the G protein existed in an altered conformation. The ts045 G protein oligosaccharides were deglucosylated in vitro by glucosidase II at both the permissive and nonpermissive temperatures. G protein isolated from ts045-infected cells labeled with [6-3H]galactose in the presence of cycloheximide contained 3H-glucose-labeled monoglucosylated oligosaccharides, indicating that the high mannose oligosaccharides were glucosylated in a posttranslational process. These results suggest that aberrant G proteins are selectively modified by resident ER enzymes to retain monoglucosylated oligosaccharides.

In Vitro Generation from the trans-Golgi Network of Coatomer-Coated Vesicles Containing Sialylated Vesicular Stomatitis Virus-G Protein

Methods ◽  
2000 ◽  
Vol 20 (4) ◽  
pp. 437-454 ◽  
Author(s):  
Jean-Pierre Simon ◽  
Ivan E. Ivanov ◽  
Milton Adesnik ◽  
David D. Sabatini
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Coated Vesicles ◽  
Trans Golgi Network ◽  
Vesicular Stomatitis ◽  
Golgi Network

scholarly journals 160. Truncated Vesicular Stomatitis Virus G- Protein Improves Baculovirus Transduction Efficiency In Vitro and In Vivo

2006 ◽  
Vol 13 ◽  
pp. S63
Author(s):  
Minna U. Kaikkonen ◽  
Jani K. Raty ◽  
Kari J. Airenne ◽  
Thomas Wirth ◽  
Tommi Heikura ◽  
...  
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Transduction Efficiency ◽  
Vesicular Stomatitis

scholarly journals Truncated vesicular stomatitis virus G protein improves baculovirus transduction efficiency in vitro and in vivo

Gene Therapy ◽  
2005 ◽  
Vol 13 (4) ◽  
pp. 304-312 ◽  
Author(s):  
M U Kaikkonen ◽  
J K Räty ◽  
K J Airenne ◽  
T Wirth ◽  
T Heikura ◽  
...  
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Transduction Efficiency ◽  
Vesicular Stomatitis

The glycoprotein of VSV accumulates in a distal Golgi compartment in the presence of CCCP

1989 ◽  
Vol 92 (4) ◽  
pp. 643-654
Author(s):  
J.K. Burkhardt ◽  
S. Hester ◽  
Y. Argon
Keyword(s):  
G Protein ◽  
Vesicular Stomatitis Virus ◽  
Preceding Paper ◽  
Marker Enzyme ◽  
Perinuclear Region ◽  
Post Translational Modifications ◽  
Golgi Stack ◽  
Golgi Compartment ◽  
Vesicular Stomatitis ◽  
Dose Dependent

The post-translational modifications of the G protein of vesicular stomatitis virus, described in the preceding paper, indicate that its transport is arrested by carbonylcyanide m-chlorophenylhydrazone (CCCP) in or near the trans-Golgi. Immunofluorescence microscopy of BHK-21 cells infected with vesicular stomatitis virus and treated with CCCP shows an accumulation of G protein in the Golgi area. In the same cells, the morphology of wheat germ agglutinin (WGA)-staining structures in the perinuclear region is aberrant. Using anti-BiP antibody, there is no obvious change in the structure of the endoplasmic reticulum. Electron microscopy reveals that the aberrant structures in the perinuclear region result from dilation of Golgi cisternae and accumulation of large vacuoles near the Golgi stack. The appearance of these aberrant structures is dose-dependent and they disappear after the protonophore is removed. The vast majority of the vacuoles accumulate on the trans side of the Golgi stack. A small fraction of them contain the marker enzyme thiamine pyrophosphatase (TPPase). By immunoelectron microscopy, most of the vacuoles contain G protein. We conclude that most of the Golgi-associated vacuoles are derived from a distal Golgi transport compartment, possibly the trans-Golgi reticulum, and that CCCP reversibly inhibits the transport of newly synthesized G protein through this distal compartment.

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