scholarly journals GxxxG Motif of Severe Acute Respiratory Syndrome Coronavirus Spike Glycoprotein Transmembrane Domain Is Not Involved in Trimerization and Is Not Important for Entry

2007 ◽  
Vol 81 (15) ◽  
pp. 8352-8355 ◽  
Author(s):  
Jeroen Corver ◽  
Rene Broer ◽  
Puck van Kasteren ◽  
Willy Spaan
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Transmembrane Domain ◽  
Vital Role ◽  
Sars Coronavirus ◽  
Spike Glycoprotein ◽  
S Protein ◽  
Mutant Proteins ◽  
Gxxxg Motif

ABSTRACT Recently, a paper was published in which it was proposed that the GxxxG motif of the severe acute respiratory syndrome (SARS) coronavirus spike (S) protein transmembrane domain plays a vital role in oligomerization of the protein (E. Arbely, Z. Granot, I. Kass, J. Orly, and I. T. Arkin, Biochemistry 45:11349-11356, 2006). Here, we show that the GxxxG motif is not involved in SARS S oligomerization by trimerization analysis of S GxxxG mutant proteins. In addition, the capability of S to mediate entry of SARS S-pseudotyped particles overall was affected moderately in the mutant proteins, also arguing for a nonvital role for the GxxxG motif in SARS coronavirus entry.

A Trimerizing GxxxG Motif Is Uniquely Inserted in the Severe Acute Respiratory Syndrome (SARS) Coronavirus Spike Protein Transmembrane Domain†

Biochemistry ◽  
2006 ◽  
Vol 45 (38) ◽  
pp. 11349-11356 ◽  
Author(s):  
Eyal Arbely ◽  
Zvi Granot ◽  
Itamar Kass ◽  
Joseph Orly ◽  
Isaiah T. Arkin
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Transmembrane Domain ◽  
Spike Protein ◽  
Sars Coronavirus ◽  
Gxxxg Motif

scholarly journals ACE2 Receptor Expression and Severe Acute Respiratory Syndrome Coronavirus Infection Depend on Differentiation of Human Airway Epithelia

2005 ◽  
Vol 79 (23) ◽  
pp. 14614-14621 ◽  
Author(s):  
Hong Peng Jia ◽  
Dwight C. Look ◽  
Lei Shi ◽  
Melissa Hickey ◽  
Lecia Pewe ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Expression ◽  
Pseudotyped Virus ◽  
Apical Surface ◽  
Sars Coronavirus ◽  
Airway Epithelia ◽  
S Protein ◽  
Human Airway ◽  
Well Differentiated ◽  
Human Airway Epithelia

ABSTRACT Studies of patients with severe acute respiratory syndrome (SARS) demonstrate that the respiratory tract is a major site of SARS-coronavirus (CoV) infection and disease morbidity. We studied host-pathogen interactions using native lung tissue and a model of well-differentiated cultures of primary human airway epithelia. Angiotensin converting enzyme 2 (ACE2), the receptor for both the SARS-CoV and the related human respiratory coronavirus NL63, was expressed in human airway epithelia as well as lung parenchyma. As assessed by immunofluorescence staining and membrane biotinylation, ACE2 protein was more abundantly expressed on the apical than the basolateral surface of polarized airway epithelia. Interestingly, ACE2 expression positively correlated with the differentiation state of epithelia. Undifferentiated cells expressing little ACE2 were poorly infected with SARS-CoV, while well-differentiated cells expressing more ACE2 were readily infected. Expression of ACE2 in poorly differentiated epithelia facilitated SARS spike (S) protein-pseudotyped virus entry. Consistent with the expression pattern of ACE2, the entry of SARS-CoV or a lentivirus pseudotyped with SARS-CoV S protein in differentiated epithelia was more efficient when applied to the apical surface. Furthermore, SARS-CoV replicated in polarized epithelia and preferentially exited via the apical surface. The results indicate that infection of human airway epithelia by SARS coronavirus correlates with the state of cell differentiation and ACE2 expression and localization. These findings have implications for understanding disease pathogenesis associated with SARS-CoV and NL63 infections.

scholarly journals The Transmembrane Domain of the Severe Acute Respiratory Syndrome Coronavirus ORF7b Protein Is Necessary and Sufficient for Its Retention in the Golgi Complex

2008 ◽  
Vol 82 (19) ◽  
pp. 9477-9491 ◽  
Author(s):  
Scott R. Schaecher ◽  
Michael S. Diamond ◽  
Andrew Pekosz
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Golgi Complex ◽  
Transmembrane Domain ◽  
Chimeric Protein ◽  
Integral Membrane Protein ◽  
Reading Frame ◽  
Mutant Proteins ◽  
Golgi Compartment ◽  
Carboxy Terminal ◽  
Necessary And Sufficient

ABSTRACT The severe acute respiratory syndrome coronavirus (SARS-CoV) ORF7b (also called 7b) protein is an integral membrane protein that is translated from a bicistronic open reading frame encoded within subgenomic RNA 7. When expressed independently or during virus infection, ORF7b accumulates in the Golgi compartment, colocalizing with both cis- and trans-Golgi markers. To identify the domains of this protein that are responsible for Golgi localization, we have generated a set of mutant proteins and analyzed their subcellular localizations by indirect immunofluorescence confocal microscopy. The N- and C-terminal sequences are dispensable, but the ORF7b transmembrane domain (TMD) is essential for Golgi compartment localization. When the TMD of human CD4 was replaced with the ORF7b TMD, the resulting chimeric protein localized to the Golgi complex. Scanning alanine mutagenesis identified two regions in the carboxy-terminal portion of the TMD that eliminated the Golgi complex localization of the chimeric CD4 proteins or ORF7b protein. Collectively, these data demonstrate that the Golgi complex retention signal of the ORF7b protein resides solely within the TMD.

scholarly journals Abstract P-14: Molecular Modeling of the Transmembrane Domain of the SARS Cov-2 S-Protein and its Interaction with the Membrane

2021 ◽  
Vol 11 (Suppl_1) ◽  
pp. S17-S17
Author(s):  
Valery Novoseletsky ◽  
Marine Bozdaganyan ◽  
Daniil Litvinov ◽  
Olga Sokolova
Keyword(s):  
Solution Structure ◽  
Structural Model ◽  
Transmembrane Domain ◽  
Coiled Coil ◽  
Bottom Layer ◽  
Dynamics Simulation ◽  
Type I ◽  
Sars Coronavirus ◽  
S Protein ◽  
Tm Domain

Background: The spike glycoprotein of SARS-coronavirus mediates the early events leading to infection of cells, including fusion of the viral and cellular membranes. The spike is a type I membrane glycoprotein that possesses a conserved transmembrane anchor and an unusual cysteine-rich domain that bridges the putative junction of the anchor and the cytoplasmic tail. In this study, we examined the role of these carboxyl-terminal domains in S-protein interaction with membrane. Methods: Structural model of the trimeric TM domain and adjacent fragments of ecto- and endo domains (residues 1157-1256) of the S-protein was built by homology basing on the solution structure of the SARS-coronavirus S-protein HR2 domain (pdb-code 2fxp), the structure of the transmembrane domain of HIV-1 gp41 in bicelle (5jyn), and assumption of generally coiled-coil fold of the considered domain. C-terminus of the domain was left unstructured but fully palmitoylated. Molecular dynamics simulation in heterogeneous lipid bilayer was prepared with CHARMM-GUI and performed with Gromacs during 100 ns. Results: 1. Ectodomain fragment (residues 1157-1212) demonstrates a tilt by the angle of 40-60 degrees from the axis of the TM domain (residues 1213-1237). This tilt is facilitated by glycine residues in position 1204. 2. Cholesterol molecules of the bottom layer tend to localize around protein due to interaction with palmitoyl tails while lipids in the upper layer do not show such tendency. Conclusion: Performed molecular simulations show that both palmitoylation and a large cluster of aromatic residues provide high stability of the S-protein TM domain.

scholarly journals Molecular Recognition of SARS-CoV-2 Spike Glycoprotein: Quantum Chemical Hot Spot and Epitope Analyses

2021 ◽  
Author(s):  
Chiduru Watanabe ◽  
Yoshio Okiyama ◽  
Shigenori Tanaka ◽  
Kaori Fukuzawa ◽  
Teruki Honma
Keyword(s):  
Molecular Recognition ◽  
Severe Acute Respiratory Syndrome ◽  
Angiotensin Converting Enzyme ◽  
Quantum Chemical ◽  
Hot Spot ◽  
Complex Structures ◽  
Converting Enzyme ◽  
Spike Glycoprotein ◽  
S Protein ◽  
Angiotensin Converting Enzyme 2

Due to the COVID-19 pandemic, researchers have attempted to identify complex structures of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike glycoprotein (S-protein) with angiotensin-converting enzyme 2 (ACE2) or...

scholarly journals The Functional Consequences of the Novel Ribosomal Pausing Site in SARS-CoV-2 Spike Glycoprotein RNA

2021 ◽  
Vol 22 (12) ◽  
pp. 6490
Author(s):  
Olga A. Postnikova ◽  
Sheetal Uppal ◽  
Weiliang Huang ◽  
Maureen A. Kane ◽  
Rafael Villasmil ◽  
...  
Keyword(s):  
Amino Acid ◽  
Insertion Sequence ◽  
Experimental Studies ◽  
Spike Protein ◽  
Spike Glycoprotein ◽  
Furin Cleavage ◽  
New Host ◽  
S Protein ◽  
Furin Cleavage Site ◽  
Ribosome Pausing

The SARS-CoV-2 Spike glycoprotein (S protein) acquired a unique new 4 amino acid -PRRA- insertion sequence at amino acid residues (aa) 681–684 that forms a new furin cleavage site in S protein as well as several new glycosylation sites. We studied various statistical properties of the -PRRA- insertion at the RNA level (CCUCGGCGGGCA). The nucleotide composition and codon usage of this sequence are different from the rest of the SARS-CoV-2 genome. One of such features is two tandem CGG codons, although the CGG codon is the rarest codon in the SARS-CoV-2 genome. This suggests that the insertion sequence could cause ribosome pausing as the result of these rare codons. Due to population variants, the Nextstrain divergence measure of the CCU codon is extremely large. We cannot exclude that this divergence might affect host immune responses/effectiveness of SARS-CoV-2 vaccines, possibilities awaiting further investigation. Our experimental studies show that the expression level of original RNA sequence “wildtype” spike protein is much lower than for codon-optimized spike protein in all studied cell lines. Interestingly, the original spike sequence produces a higher titer of pseudoviral particles and a higher level of infection. Further mutagenesis experiments suggest that this dual-effect insert, comprised of a combination of overlapping translation pausing and furin sites, has allowed SARS-CoV-2 to infect its new host (human) more readily. This underlines the importance of ribosome pausing to allow efficient regulation of protein expression and also of cotranslational subdomain folding.

scholarly journals Amino Acids 1055 to 1192 in the S2 Region of Severe Acute Respiratory Syndrome Coronavirus S Protein Induce Neutralizing Antibodies: Implications for the Development of Vaccines and Antiviral Agents

2005 ◽  
Vol 79 (6) ◽  
pp. 3289-3296 ◽  
Author(s):  
Choong-Tat Keng ◽  
Aihua Zhang ◽  
Shuo Shen ◽  
Kuo-Ming Lip ◽  
Burtram C. Fielding ◽  
...  
Keyword(s):  
Amino Acids ◽  
Severe Acute Respiratory Syndrome ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Antiviral Agents ◽  
Host Cells ◽  
Heptad Repeat ◽  
Antigenic Determinants ◽  
Amino Acid Residues ◽  
S Protein

ABSTRACT The spike (S) protein of the severe acute respiratory syndrome coronavirus (SARS-CoV) interacts with cellular receptors to mediate membrane fusion, allowing viral entry into host cells; hence it is recognized as the primary target of neutralizing antibodies, and therefore knowledge of antigenic determinants that can elicit neutralizing antibodies could be beneficial for the development of a protective vaccine. Here, we expressed five different fragments of S, covering the entire ectodomain (amino acids 48 to 1192), as glutathione S-transferase fusion proteins in Escherichia coli and used the purified proteins to raise antibodies in rabbits. By Western blot analysis and immunoprecipitation experiments, we showed that all the antibodies are specific and highly sensitive to both the native and denatured forms of the full-length S protein expressed in virus-infected cells and transfected cells, respectively. Indirect immunofluorescence performed on fixed but unpermeabilized cells showed that these antibodies can recognize the mature form of S on the cell surface. All the antibodies were also able to detect the maturation of the 200-kDa form of S to the 210-kDa form by pulse-chase experiments. When the antibodies were tested for their ability to inhibit SARS-CoV propagation in Vero E6 culture, it was found that the anti-SΔ10 antibody, which was targeted to amino acid residues 1029 to 1192 of S, which include heptad repeat 2, has strong neutralizing activities, suggesting that this region of S carries neutralizing epitopes and is very important for virus entry into cells.

scholarly journals Do sex-specific immunobiological factors and differences in angiotensin converting enzyme 2 (ACE2) expression explain increased severity and mortality of COVID-19 in males?

Diagnosis ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 385-386 ◽  
Author(s):  
Jens Vikse ◽  
Giuseppe Lippi ◽  
Brandon Michael Henry
Keyword(s):  
Mortality Rate ◽  
Severe Acute Respiratory Syndrome ◽  
Lung Injury ◽  
Angiotensin Converting Enzyme ◽  
Converting Enzyme ◽  
Sars Coronavirus ◽  
Immunomodulatory Treatment ◽  
Angiotensin Converting Enzyme 2 ◽  
Cytopathic Effects ◽  
Severe Lung

AbstractCoronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome (SARS) coronavirus 2 (SARS-CoV-2), shares similarities with the former SARS outbreak, which was caused by SARS-CoV-1. SARS was characterized by severe lung injury due to virus-induced cytopathic effects and dysregulated hyperinflammatory state. COVID-19 has a higher mortality rate in men both inside and outside China. In this opinion paper, we describe how sex-specific immunobiological factors and differences in angiotensin converting enzyme 2 (ACE2) expression may explain the increased severity and mortality of COVID-19 in males. We highlight that immunomodulatory treatment must be tailored to the underlying immunobiology at different stages of disease. Moreover, by investigating sex-based immunobiological differences, we may enhance our understanding of COVID-19 pathophysiology and facilitate improved immunomodulatory strategies.

Sign in / Sign up

Export Citation Format

Share Document