The pandemic caused by the SARS-CoV-2 virus, the agent responsible for the COVID-19 disease, has affected millions of people worldwide. There is constant search for new therapies to either prevent or mitigate the disease. Fortunately, we have observed the successful development of multiple vaccines. Most of them are focused on one viral envelope protein, the spike protein. However, such focused approaches may contribute for the rise of new variants, fueled by the constant selection pressure on envelope proteins, and the widespread dispersion of coronaviruses in nature. Therefore, it is important to examine other proteins, preferentially those that are less susceptible to selection pressure, such as the nucleocapsid (N) protein. Even though the N protein is less accessible to humoral response, peptides from its conserved regions can be presented by class I Human Leukocyte Antigen (HLA) molecules, eliciting an immune response mediated by T-cells. Given the increased number of protein sequences deposited in biological databases daily and the N protein conservation among viral strains, computational methods can be leveraged to discover potential new targets for SARS-CoV-2 and SARS-CoV-related viruses. Here we developed SARS-Arena, a user-friendly computational pipeline that can be used by practitioners of different levels of expertise for novel vaccine development. SARS-Arena combines sequence-based methods and structure-based analyses to (i) perform multiple sequence alignment (MSA) of SARS-CoV-related N protein sequences, (ii) recover candidate peptides of different lengths from conserved protein regions, and (iii) model the 3D structure of the conserved peptides in the context of different HLAs. We present two main Jupyter Notebook workflows that can help in the identification of new T-cell targets against SARS-CoV viruses. In fact, in a cross-reactive case study, our workflows identified a conserved N protein peptide (SPRWYFYYL) recognized by CD8 + T-cells in the context of HLA-B7 + . SARS-Arena is available at https://github.com/KavrakiLab/SARS-Arena .
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SARSNTdb database: Factors affecting SARS-CoV-2 sequence conservation
SARSNTdb offers a curated, nucleotide-centric database for users of varying levels of SARS-CoV-2 knowledge. Its user-friendly interface enables querying coding regions and coordinate intervals to find out the various functional and selective constraints that act upon the corresponding nucleotides and amino acids. Users can easily obtain information about viral genes and proteins, functional domains, repeats, secondary structure formation, intragenomic interactions, and mutation prevalence. Currently, many databases are focused on the phylogeny and amino acid substitutions, mainly in the spike protein. We took a novel, more nucleotide-focused approach as RNA does more than just code for proteins and many insights can be gleaned from its study. For example, RNA-targeted drug therapies for SARS-CoV-2 are currently being developed and it is essential to understand the features only visible at that level. This database enables the user to identify regions that are more prone to forming secondary structures that drugs can target. SARSNTdb also provides illustrative mutation data from a subset of ~25,000 patient samples with a reliable read coverage across the whole genome (from different locations and time points in the pandemic. Finally, the database allows for comparing SARS-CoV-2 and SARS-CoV domains and sequences. SARSNTdb can serve the research community by being a curated repository for information that gives a jump start to analyze a mutation’s effect far beyond just determining synonymous/non-synonymous substitutions in protein sequences.
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- Award ID(s):
- 2027611
- NSF-PAR ID:
- 10410325
- Date Published:
- Journal Name:
- Frontiers in Virology
- Volume:
- 2
- ISSN:
- 2673-818X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract PhyloFisher is a software package written primarily in Python3 that can be used for the creation, analysis, and visualization of phylogenomic datasets that consist of protein sequences from eukaryotic organisms. Unlike many existing phylogenomic pipelines, PhyloFisher comes with a manually curated database of 240 protein‐coding genes, a subset of a previous phylogenetic dataset sampled from 304 eukaryotic taxa. The software package can also utilize a user‐created database of eukaryotic proteins, which may be more appropriate for shallow evolutionary questions. PhyloFisher is also equipped with a set of utilities to aid in running routine analyses, such as the prediction of alternative genetic codes, removal of genes and/or taxa based on occupancy/completeness of the dataset, testing for amino acid compositional heterogeneity among sequences, removal of heterotachious and/or fast‐evolving sites, removal of fast‐evolving taxa, supermatrix creation from randomly resampled genes, and supermatrix creation from nucleotide sequences. © 2024 Wiley Periodicals LLC.
Basic Protocol 1 : Constructing a phylogenomic datasetBasic Protocol 2 : Performing phylogenomic analysesSupport Protocol 1 : Installing PhyloFisherSupport Protocol 2 : Creating a custom phylogenomic database -
Abstract Coronavirus disease (COVID-19) is a contagious respiratory disease caused by the SARS-CoV-2 virus. The clinical phenotypes are variable, ranging from spontaneous recovery to serious illness and death. On March 2020, a global COVID-19 pandemic was declared by the World Health Organization (WHO). As of February 2023, almost 670 million cases and 6,8 million deaths have been confirmed worldwide. Coronaviruses, including SARS-CoV-2, contain a single-stranded RNA genome enclosed in a viral capsid consisting of four structural proteins: the nucleocapsid (N) protein, in the ribonucleoprotein core, the spike (S) protein, the envelope (E) protein, and the membrane (M) protein, embedded in the surface envelope. In particular, the E protein is a poorly characterized viroporin with high identity amongst all the β-coronaviruses (SARS-CoV-2, SARS-CoV, MERS-CoV, HCoV-OC43) and a low mutation rate. Here, we focused our attention on the study of SARS-CoV-2 E and M proteins, and we found a general perturbation of the host cell calcium (Ca 2+ ) homeostasis and a selective rearrangement of the interorganelle contact sites. In vitro and in vivo biochemical analyses revealed that the binding of specific nanobodies to soluble regions of SARS-CoV-2 E protein reversed the observed phenotypes, suggesting that the E protein might be an important therapeutic candidate not only for vaccine development, but also for the clinical management of COVID designing drug regimens that, so far, are very limited.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.3389/fviro.2022.1028335
