scholarly journals Construction of a synthetic messenger RNA encoding a membrane protein.

1983 ◽  
Vol 96 (5) ◽  
pp. 1464-1469 ◽  
Author(s):  
J L Rubenstein ◽  
T G Chappell

We have synthesized microgram quantities of a functional eucaryotic mRNA by in vitro transcription. For this purpose, we constructed a plasmid in which the Escherichia coli lactose promoter was 5' to the vesicular stomatitis virus (VSV) G protein gene (Rose, J. K., and C. J. Gallione, 1981, J. Virol., 39:519-528). This DNA served as the template in an in vitro transcription reaction utilizing E. coli RNA polymerase. The RNA product was capped using the vaccinia guanylyltransferase. A typical preparation of the synthetic G mRNA was equivalent to the amount of G mRNA that can be isolated from approximately 10(8) VSV-infected cells. This synthetic mRNA was translated by a wheat germ extract in the presence of microsomes, producing a polypeptide that was indistinguishable from G protein in its size, antigenicity, degree of glycosylation, and its membrane insertion. This technique should aid in identifying features needed by proteins for insertion into membranes.

1989 ◽  
Vol 108 (3) ◽  
pp. 811-819 ◽  
Author(s):  
K Suh ◽  
J E Bergmann ◽  
C A Gabel

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.


1979 ◽  
Vol 80 (2) ◽  
pp. 416-426 ◽  
Author(s):  
F N Katz ◽  
H F Lodish

Previous work has shown that the mRNA encoding the vesicular stomatitis virus (VSV) glycoprotein (G) is bound to the rough endoplasmic reticulum (RER) and that newly made G protein is localized to the RER. In this paper, we have investigated the topology and processing of the newly synthesized G protein in microsomal vesicles. G was labeled with [35S]methionine ([35S]met), either by pulse-labeling infected cells or by allowing membrane-bound polysomes containing nascent G polipeptides to complete G synthesis in vitro. In either case, digestion of microsomal vesicles with any of several proteases removes approximately 5% (30 amino acids) from each G molecule. These proteases will digest the entire G protein if detergents are present during digestion. Using the method of Dintzis (1961, Proc. Natl. Acad. Sci. U. S. A. 47:247--261) to order tryptic peptides (8), we show that peptides lost from G protein by protease treatment of closed vesicles are derived from the carboxyterminus of the molecule. The newly made VSV G in microsomal membranes is glycosylated. If carbohydrate is removed by glycosidases, the resultant peptide migrates more rapidly on polyacrylamide gels than the unglycosylated, G0, form synthesized in cell-free systems in the absence of membranes. We infer that some proteolytic cleavage of the polypeptide backbone is associated with membrane insertion of G. Further, our findings demonstrate that, soon after synthesis, G is found in a transmembrane, asymmetric orientation in microsomal membranes, with its carboxyterminus exposed to the extracisternal, or cytoplasmic, face of the vesicles, and with most or all of its amino-terminal peptides and its carbohydrate sequestered within the bilayer and lumen of the microsomes.


1995 ◽  
Vol 41 (1) ◽  
pp. 75-87 ◽  
Author(s):  
Zerlina M. Naczynski ◽  
Andrew M. Kropinski ◽  
Chris Mueller

A 31 base pair synthetic oligonucleotide based on the genes for the Escherichia coli heat shock sigma factor (rpoH) and the Pseudomonas aeruginosa housekeeping sigma factor (rpoD) was employed in conjunction with the Tanaka et al. (K. Tanaka, T. Shiina, and H. Takahashi, 1988. Science (Washington, D.C.), 242: 1040–1042) RpoD box probe to identify the location of the rpoH gene in P. aeruginosa genomic digests. This gene was cloned into plasmid pGEM3Z(f+), sequenced, and found to share 67% nucleotide identity and 77% amino acid homology with the rpoH gene and its product (σ32) of E. coli. The plasmid containing the rpoH gene complemented the function of σ32 in an E. coli rpoH deletion mutant. Furthermore, this plasmid directed the synthesis of a 32-kDa protein in an E. coli S-30 in vitro transcription–translation system. Primer extension studies were used to identify the transcriptional start sites under control and heat-stressed (45 and 50 °C) conditions. Two promoter sites were identified having sequence homology to the E. coli σ70 and σ24 consensus sequences.Key words: heat shock, Pseudomonas aeruginosa, sigma factor, transcription, oligonucleotide probe.


Life ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1192
Author(s):  
Hideyuki Nakanishi

Synthetic mRNAs, which are produced by in vitro transcription, have been recently attracting attention because they can express any transgenes without the risk of insertional mutagenesis. Although current synthetic mRNA medicine is not designed for spatiotemporal or cell-selective regulation, many preclinical studies have developed the systems for the translational regulation of synthetic mRNAs. Such translational regulation systems will cope with high efficacy and low adverse effects by producing the appropriate amount of therapeutic proteins, depending on the context. Protein-based regulation is one of the most promising approaches for the translational regulation of synthetic mRNAs. As synthetic mRNAs can encode not only output proteins but also regulator proteins, all components of protein-based regulation systems can be delivered as synthetic mRNAs. In addition, in the protein-based regulation systems, the output protein can be utilized as the input for the subsequent regulation to construct multi-layered gene circuits, which enable complex and sophisticated regulation. In this review, I introduce what types of proteins have been used for translational regulation, how to combine them, and how to design effective gene circuits.


2020 ◽  
Vol 48 (17) ◽  
pp. 9931-9942 ◽  
Author(s):  
Fulin Wang ◽  
Jing Shi ◽  
Dingwei He ◽  
Bei Tong ◽  
Chao Zhang ◽  
...  

Abstract Stringent starvation protein A (SspA) is an RNA polymerase (RNAP)-associated protein involved in nucleotide metabolism, acid tolerance and virulence of bacteria. Despite extensive biochemical and genetic analyses, the precise regulatory role of SspA in transcription is still unknown, in part, because of a lack of structural information for bacterial RNAP in complex with SspA. Here, we report a 3.68 Å cryo-EM structure of an Escherichia coli RNAP-promoter open complex (RPo) with SspA. Unexpectedly, the structure reveals that SspA binds to the E. coli σ70-RNAP holoenzyme as a homodimer, interacting with σ70 region 4 and the zinc binding domain of EcoRNAP β′ subunit simultaneously. Results from fluorescent polarization assays indicate the specific interactions between SspA and σ70 region 4 confer its σ selectivity, thereby avoiding its interactions with σs or other alternative σ factors. In addition, results from in vitro transcription assays verify that SspA inhibits transcription probably through suppressing promoter escape. Together, the results here provide a foundation for understanding the unique physiological function of SspA in transcription regulation in bacteria.


2000 ◽  
Vol 74 (21) ◽  
pp. 9911-9915 ◽  
Author(s):  
Séverine Vincent ◽  
Denis Gerlier ◽  
Serge N. Manié

ABSTRACT During measles virus (MV) replication, approximately half of the internal M and N proteins, together with envelope H and F glycoproteins, are selectively enriched in microdomains rich in cholesterol and sphingolipids called membrane rafts. Rafts isolated from MV-infected cells after cold Triton X-100 solubilization and flotation in a sucrose gradient contain all MV components and are infectious. Furthermore, the H and F glycoproteins from released virus are also partly in membrane rafts (S. N. Manié et al., J. Virol. 74:305–311, 2000). When expressed alone, the M but not N protein shows a low partitioning (around 10%) into rafts; this distribution is unchanged when all of the internal proteins, M, N, P, and L, are coexpressed. After infection with MGV, a chimeric MV where both H and F proteins have been replaced by vesicular stomatitis virus G protein, both the M and N proteins were found enriched in membrane rafts, whereas the G protein was not. These data suggest that assembly of internal MV proteins into rafts requires the presence of the MV genome. The F but not H glycoprotein has the intrinsic ability to be localized in rafts. When coexpressed with F, the H glycoprotein is dragged into the rafts. This is not observed following coexpression of either the M or N protein. We propose a model for MV assembly into membrane rafts where the virus envelope and the ribonucleoparticle colocalize and associate.


1981 ◽  
Vol 90 (3) ◽  
pp. 697-704 ◽  
Author(s):  
E Fries ◽  
J E Rothman

Previous reports demonstrated that the vesicular stomatitis viral glycoprotein (G protein), initially present in membranes of a Chinese hamster ovary mutant cell line (clone 15B) that is incapable of terminal glycosylation, can be transferred in vitro to exogenous Golgi membranes and there glycosylated (E. Fries and J. E. Rothman, 1980, Proc. Natl. Acad. Sci. U. S. A. 77:3870-3874; and J. E. Rothman and E. Fries, 1981, J. Cell Biol. 89:162-168). Here we present evidence that Golgi-like membranes serve as donors of G protein in this process. Pulse-chase experiments revealed that the donor activity of membranes is greatest at approximately 10 min of chase, a time when G protein has been shown to have arrived in Golgi stacks (J. E. Bergmann, K. T. Tokuyasu, and S. J. Singer, 1981, Proc. Natl. Acad. Sci. U. S. A. 78:1746-1750). Additional evidence that the G protein that is transferred to exogenous Golgi membranes in vitro had already entered the Golgi membranes in vivo was provided by observations that its oligosaccharides had already been trimmed, and that its distribution in a sucrose density gradient was coincident with that of enzymatic markers of Golgi membranes. The capacity of this Golgi-like membrane to serve as donor is transient, declining within 5 min after "trimming" in vivo as the G protein enters a "nontransferable" pool. The rapidity of the process suggests that both the "transferable" and "nontransferable" pools of G protein reside in Golgi-like membranes.


1992 ◽  
Vol 70 (8) ◽  
pp. 698-702 ◽  
Author(s):  
Elana Swartzman ◽  
Edward A. Meighen

RNA polymerase was purified from Vibrio harveyi and found to contain polypeptides (β,β′, α, and σ) closely corresponding to those of the Escherichia coli enzyme. In vitro transcription studies using V. harveyi and E. coli RNA polymerase demonstrated that the purified V. harveyi RNA polymerase is functional and that the two enzymes have the same promoter specificity. Chromatography through a monoQ column was required to remove a 100-kilodalton protein that was present in large amounts and copurified with the RNA polymerase. N-terminal amino acid sequencing showed that the first 18 amino acids of the 100-kilodalton protein shares 78% sequence identity with the A subunit of gyrase or topoisomerase II. The abundance of the gyrase A protein is unprecedented and may be linked to bioluminescence.Key words: Vibrio harveyi, RNA polymerase, gyrase, bioluminescence.


Sign in / Sign up

Export Citation Format

Share Document