scholarly journals Predicted Coronavirus Nsp5 Protease Cleavage Sites in the Human Proteome: A Resource for SARS-CoV-2 Research

2021 ◽  
Author(s):  
Benjamin M Scott ◽  
Vincent Lacasse ◽  
Ditte G Blom ◽  
Peter D Tonner ◽  
Nikolaj S Blom
Keyword(s):  
Protein Interactions ◽  
Cleavage Site ◽  
Nonstructural Protein ◽  
Data Bank ◽  
Molecular Pathways ◽  
Cleavage Sites ◽  
Host Proteins ◽  
Structure Information ◽  
Human Proteins

Background: The coronavirus nonstructural protein 5 (Nsp5) is a cysteine protease required for processing the viral polyprotein and is therefore crucial for viral replication. Nsp5 from several coronaviruses have also been found to cleave host proteins, disrupting molecular pathways involved in innate immunity. Nsp5 from the recently emerged SARS-CoV-2 virus interacts with and can cleave human proteins, which may be relevant to the pathogenesis of COVID-19. Based on the continuing global pandemic, and emerging understanding of coronavirus Nsp5-human protein interactions, we set out to predict what human proteins are cleaved by the coronavirus Nsp5 protease using a bioinformatics approach. Results: Using a previously developed neural network trained on coronavirus Nsp5 cleavage sites (NetCorona), we made predictions of Nsp5 cleavage sites in all human proteins. Structures of human proteins in the Protein Data Bank containing a predicted Nsp5 cleavage site were then examined, generating a list of 92 human proteins with a highly predicted and accessible cleavage site. Of those, 48 are expected to be found in the same cellular compartment as Nsp5. Analysis of this targeted list of proteins revealed molecular pathways susceptible to Nsp5 cleavage and therefore relevant to coronavirus infection, including pathways involved in mRNA processing, cytokine response, cytoskeleton organization, and apoptosis. Conclusions: This study combines predictions of Nsp5 cleavage sites in human proteins with protein structure information and protein network analysis. We predicted cleavage sites in proteins recently shown to be cleaved in vitro by SARS-CoV-2 Nsp5, and we discuss how other potentially cleaved proteins may be relevant to coronavirus mediated immune dysregulation. The data presented here will assist in the design of more targeted experiments, to determine the role of coronavirus Nsp5 cleavage of host proteins, which is relevant to understanding the molecular pathology of SARS-CoV-2 infection.

scholarly journals Neuropsychiatric Symptoms of COVID-19 Explained by SARS-CoV-2 Proteins’ Mimicry of Human Protein Interactions

2021 ◽  
Vol 15 ◽  
Author(s):  
Hale Yapici-Eser ◽  
Yunus Emre Koroglu ◽  
Ozgur Oztop-Cakmak ◽  
Ozlem Keskin ◽  
Attila Gursoy ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Clinical Symptoms ◽  
Neuropsychiatric Symptoms ◽  
Data Bank ◽  
In Vitro Studies ◽  
Human Protein ◽  
Protein Protein Interactions ◽  
Human Proteins

The first clinical symptoms focused on the presentation of coronavirus disease 2019 (COVID-19) have been respiratory failure, however, accumulating evidence also points to its presentation with neuropsychiatric symptoms, the exact mechanisms of which are not well known. By using a computational methodology, we aimed to explain the molecular paths of COVID-19 associated neuropsychiatric symptoms, based on the mimicry of the human protein interactions with SARS-CoV-2 proteins.Methods: Available 11 of the 29 SARS-CoV-2 proteins’ structures have been extracted from Protein Data Bank. HMI-PRED (Host-Microbe Interaction PREDiction), a recently developed web server for structural PREDiction of protein-protein interactions (PPIs) between host and any microbial species, was used to find the “interface mimicry” through which the microbial proteins hijack host binding surfaces. Classification of the found interactions was conducted using the PANTHER Classification System.Results: Predicted Human-SARS-CoV-2 protein interactions have been extensively compared with the literature. Based on the analysis of the molecular functions, cellular localizations and pathways related to human proteins, SARS-CoV-2 proteins are found to possibly interact with human proteins linked to synaptic vesicle trafficking, endocytosis, axonal transport, neurotransmission, growth factors, mitochondrial and blood-brain barrier elements, in addition to its peripheral interactions with proteins linked to thrombosis, inflammation and metabolic control.Conclusion: SARS-CoV-2-human protein interactions may lead to the development of delirium, psychosis, seizures, encephalitis, stroke, sensory impairments, peripheral nerve diseases, and autoimmune disorders. Our findings are also supported by the previous in vivo and in vitro studies from other viruses. Further in vivo and in vitro studies using the proteins that are pointed here, could pave new targets both for avoiding and reversing neuropsychiatric presentations.

scholarly journals Molecular Determinants of Substrate Specificity for Semliki Forest Virus Nonstructural Protease

2006 ◽  
Vol 80 (11) ◽  
pp. 5413-5422 ◽  
Author(s):  
Aleksei Lulla ◽  
Valeria Lulla ◽  
Kairit Tints ◽  
Tero Ahola ◽  
Andres Merits
Keyword(s):  
Life Cycle ◽  
Amino Acid ◽  
Cleavage Site ◽  
Semliki Forest Virus ◽  
Nonstructural Protein ◽  
Cleavage Sites ◽  
Vitro Assay ◽  
Virus Life Cycle ◽  
Cleavage Efficiency

ABSTRACT The C-terminal cysteine protease domain of Semliki Forest virus nonstructural protein 2 (nsP2) regulates the virus life cycle by sequentially cleaving at three specific sites within the virus-encoded replicase polyprotein P1234. The site between nsP3 and nsP4 (the 3/4 site) is cleaved most efficiently. Analysis of Semliki Forest virus-specific cleavage sites with shuffled N-terminal and C-terminal half-sites showed that the main determinants of cleavage efficiency are located in the region preceding the cleavage site. Random mutagenesis analysis revealed that amino acid residues in positions P4, P3, P2, and P1 of the 3/4 cleavage site cannot tolerate much variation, whereas in the P5 position most residues were permitted. When mutations affecting cleavage efficiency were introduced into the 2/3 and 3/4 cleavage sites, the resulting viruses remained viable but had similar defects in P1234 processing as observed in the in vitro assay. Complete blockage of the 3/4 cleavage was found to be lethal. The amino acid in position P1′ had a significant effect on cleavage efficiency, and in this regard the protease markedly preferred a glycine residue over the tyrosine natively present in the 3/4 site. Therefore, the cleavage sites represent a compromise between protease recognition and other requirements of the virus life cycle. The protease recognizes at least residues P4 to P1′, and the P4 arginine residue plays an important role in the fast cleavage of the 3/4 site.

scholarly journals Prediction of coronavirus 3C-like protease cleavage sites using machine-learning algorithms

2021 ◽  
Author(s):  
Huiting Chen ◽  
Zhaozhong Zhu ◽  
Ye Qiu ◽  
Xingyi Ge ◽  
Heping Zheng ◽  
...  
Keyword(s):  
Cleavage Site ◽  
Immune Escape ◽  
Machine Learning Algorithms ◽  
Cleavage Sites ◽  
Host Proteins ◽  
Independent Test Dataset ◽  
Human Proteins ◽  
Protease Cleavage Sites ◽  
Viral Polyprotein ◽  
3Cl Protease

The coronavirus 3C-like (3CL) protease is a Cysteine protease. It plays an important role in viral infection and immune escape by not only cleaving the viral polyprotein ORF1ab at 11 sites, but also cleaving the host proteins. However, there is still a lack of effective tools for determining the cleavage sites of the 3CL protease. This study systematically investigated the diversity of the cleavage sites of the coronavirus 3CL protease on the viral polyprotein, and found that the cleavage motif were highly conserved for viruses in the genera of Alphacoronavirus, Betacoronavirus and Gammacoronavirus. Strong residue preferences were observed at the neighboring positions of the cleavage sites. A random forest (RF) model was built to predict the cleavage sites of the coronavirus 3CL protease based on the representation of residues at cleavage site and neighboring positions by amino acid indexes, and the model achieved an AUC of 0.96 in cross-validations. The RF model was further tested on an independent test dataset composed of cleavage sites on host proteins, and achieved an AUC of 0.88 and a prediction precision of 0.80 when considering the accessibility of the cleavage site. Then, 1,079 human proteins were predicted to be cleaved by the 3CL protease by the RF model. These proteins were enriched in pathways related to neurodegenerative diseases and pathogen infection. Finally, a user-friendly online server named 3CLP was built to predict the cleavage sites of the coronavirus 3CL protease based on the RF model. Overall, the study not only provides an effective tool for identifying the cleavage sites of the 3CL protease, but also provides insights into the molecular mechanism underlying the pathogenicity of coronaviruses.

DIRECTED MUTAGENESIS IN THE STUDY OF THE REQUIREMENTS FOR FACTOR VIII ACTIVITY IN VITRO AND IN VIVO

1987 ◽  
Author(s):  
Randal J Kaufman ◽  
Debra D Pittman ◽  
Louise C Wasley ◽  
W Barry Foster ◽  
Godfrey W Amphlett ◽  
...  
Keyword(s):  
Amino Acids ◽  
Factor Viii ◽  
Cleavage Site ◽  
Factor Xa ◽  
Cleavage Sites ◽  
Thrombin Cleavage ◽  
Terminal Fragment ◽  
Cofactor Activity

Factor VIII is a high molecular weight plasma glycoprotein that functions in the blood clotting cascade as the cofactor for factor DCa proteolytic activation of factor X. Factor VIII does not function proteolytically in this reaction hut itself can be proteolytically activated by other coagulation enzymes such as factor Xa and thrombin. In the plasma, factor VIII exists as a 200 kDa amino-terminal fragment in a metal ion stabilized complex with a 76 kDa carboxy-terminal fragment. The isolation of the cENA for human factor VIII provided the deduced primary amino acid sequence of factor VIIT and revealed three distinct structural domains: 1) a triplicated A domain of 330 amino acids which has homology to ceruloplasmin, a plasma copper binding protein, 2) a duplicated C domain of 150 amino acids, and 3) a unique B domain of 980 amino acids. These domains are arranged as shown below. We have previously reported the B domain is dispensible far cofactor activity in vitro (Toole et al. 1986 Proc. Natl. Acad 5939). The in vivo efficacy of factor VIII molecules harboring the B domain deletion was tested by purification of the wildtype and modified forms and infusion into factor VIII deficient, hemophilic, dogs. The wildtype and the deleted forms of recombinant derived factor VIII exhibited very similar survival curves (Tl/2 = 13 hrs) and the cuticle bleeding times suggested that both preparations appeared functionally equivalent. Sepharose 4B chromatography indicated that both factor VIII molecules were capable of binding canine plasma vWF.Further studies have addressed what cleavages are necessary for activation of factor VIII. The position of the thrombin, factor Xa, and activated protein C (AFC) cleavage sites within factor VIII are presented below, site-directed ENA medicated mutagenesis has been performed to modify the arginine at the amino side of each cleavagesite to an soleucine. In all cases this modification resulted in molecules that were resistant to cleavage by thrombin at the modified site. Modification of the thrombin cleavage sites at 336 and 740 and modification of the factor Xa cleavage site at 1721 resulted in no loss of cofactor activity. Modification of the thrombin cleavage site at either 372 or 1689 destroyed oofactor activity. Modification of the thrombin cleavage site at 336 resulted in a factor VIII having an increased activity, possibly due to resistance to inactivation. These results suggest the requirement of cleavage at residues 372 and 1689 for cofactor activity.

scholarly journals A map of direct SARS-CoV-2 protein interactions implicates specific human host processes

2021 ◽  
Author(s):  
Dae-Kyum Kim ◽  
Benjamin Weller ◽  
Chung-Wen Lin ◽  
Dayag Sheykhkarimli ◽  
Jennifer J Knapp ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Membrane Trafficking ◽  
Host Protein ◽  
Host Proteins ◽  
Systematic Map ◽  
High Data ◽  
Protein Ubiquitination ◽  
Human Proteins ◽  
Physical Interactions ◽  
Key Steps

Key steps in viral propagation, immune suppression and pathology are mediated by direct, binary physical interactions between viral and host proteins. To understand the biology of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, we generated an unbiased systematic map of binary physical interactions between viral and host interactions, complementing previous co-complex association maps by conveying more direct mechanistic understanding and enabling targeted disruption of direct interactions. To this end, we deployed two parallel strategies, identifying 205 virus-host and 27 intraviral binary interactions amongst 171 host and 19 viral proteins, with orthogonal validation by an internally benchmarked NanoLuc two-hybrid system to ensure high data quality. Host proteins interacting with SARS-CoV-2 proteins were enriched in various cellular processes, including immune signaling and inflammation, protein ubiquitination, and membrane trafficking. Specific subnetworks provide new hypotheses related to viral modulation of host protein homeostasis and T-cell regulation. The direct virus-host protein interactions we identified can now be prioritized as targets for therapeutic intervention. More generally, we provide a resource of systematic maps describing which SARS-CoV-2 and human proteins interact directly.

scholarly journals A Novel Rice Curl Dwarf-Associated Picornavirus Encodes a 3C Serine Protease Recognizing Uncommon EPT/S Cleavage Sites

2021 ◽  
Vol 12 ◽  
Author(s):  
Tianze Zhang ◽  
Chenyang Li ◽  
Mengji Cao ◽  
Dan Wang ◽  
Qi Wang ◽  
...  
Keyword(s):  
Serine Protease ◽  
Genome Organization ◽  
Cleavage Site ◽  
Cysteine Proteases ◽  
Cleavage Sites ◽  
Rna Seq ◽  
3C Protease ◽  
Wide Range ◽  
Sequence Identities

Picornaviruses cause diseases in a wide range of vertebrates, invertebrates and plants. Here, a novel picornavirus was identified by RNA-seq technology from rice plants showing dwarfing and curling symptoms, and the name rice curl dwarf-associated virus (RCDaV) is tentatively proposed. The RCDaV genome consists of an 8,987 nt positive-stranded RNA molecule, excluding a poly(A) tail, that encodes two large polyproteins. Using in vitro cleavage assays, we have identified that the RCDaV 3C protease (3Cpro) as a serine protease recognizes the conserved EPT/S cleavage site which differs from the classic Q(E)/G(S) sites cleaved by most picornaviral 3C chymotrypsin-like cysteine proteases. Therefore, we comprehensively deciphered the RCDaV genome organization and showed that the two polyproteins of RCDaV can be cleaved into 12 mature proteins. We found that seven unclassified picornaviruses also encode a 3Cpro similar to RCDaV, and use the highly conserved EPT/S as the cleavage site. The precise genome organizations of these viruses were illustrated. Moreover, RCDaV and the seven unclassified picornaviruses share high sequence identities and similar genome organizations, and cluster into a distinct clade in the order Picornavirales. Our study provides valuable information for the understanding of picornaviral 3Cpros, deciphers the genome organization of a few relatively obscure picornaviruses, and lays the foundation for further pathogenesis research on these viruses.

scholarly journals Genomic organization of RNA2 of Tomato ringspot virus: processing at a third cleavage site in the N-terminal region of the polyprotein in vitro

2001 ◽  
Vol 82 (7) ◽  
pp. 1785-1790 ◽  
Author(s):  
Karma Carrier ◽  
Yu Xiang ◽  
Hélène Sanfaçon
Keyword(s):  
Cleavage Site ◽  
Terminal Region ◽  
Ringspot Virus ◽  
Protein Domain ◽  
Site Directed Mutagenesis ◽  
Cdna Clones ◽  
Cleavage Sites ◽  
Tomato Ringspot Virus ◽  
Definition Of

The proteinase of Tomato ringspot virus (genus Nepovirus) is responsible for proteolytic cleavage of the RNA2-encoded polyprotein (P2) at two cleavage sites, allowing definition of the domains for the movement protein (MP) and coat protein. In this study, we have characterized a third cleavage site in the N-terminal region of P2 using an in vitro processing assay and partial cDNA clones. Results from site-directed mutagenesis of putative cleavage sites suggest that cleavage occurs at dipeptide Q301/G. Cleavage at this site is predicted to result in the release of two proteins from the N-terminal region of P2: a 34 kDa protein located at the N terminus of P2 (assuming translation initiation at the first AUG codon) and a 71 kDa protein located immediately upstream of the MP domain. In contrast, only one protein domain is present in the equivalent region of the P2 polyprotein of other characterized nepoviruses.

An improved method for predicting interactions between virus and human proteins

2017 ◽  
Vol 15 (01) ◽  
pp. 1650024 ◽  
Author(s):  
Byungmin Kim ◽  
Saud Alguwaizani ◽  
Xiang Zhou ◽  
De-Shuang Huang ◽  
Byunkyu Park ◽  
...  
Keyword(s):  
Amino Acid ◽  
Computational Methods ◽  
Protein Interactions ◽  
Human Papillomaviruses ◽  
Support Vector ◽  
Protein Protein Interactions ◽  
Host Proteins ◽  
Human Ppis ◽  
Human Proteins ◽  
Key Features

The interaction of virus proteins with host proteins plays a key role in viral infection and consequent pathogenesis. Many computational methods have been proposed to predict protein–protein interactions (PPIs), but most of the computational methods are intended for PPIs within a species rather than PPIs across different species such as virus–host PPIs. We developed a method that represents key features of virus and human proteins of variable length into a feature vector of fixed length. The key features include the relative frequency of amino acid triplets (RFAT), the frequency difference of amino acid triplets (FDAT) between virus and host proteins, and amino acid composition (AC). We constructed several support vector machine (SVM) models to evaluate our method and to compare our method with others on PPIs between human and two types of viruses: human papillomaviruses (HPV) and hepatitis C virus (HCV). Comparison of our method to others with same datasets of HPV–human PPIs and HCV–human PPIs showed that the performance of our method is significantly higher than others in all performance measures. Using the SVM model with gene ontology (GO) annotations of proteins, we predicted new HPV–human PPIs. We believe our approach will be useful in predicting heterogeneous PPIs.

scholarly journals Different Subtypes of Influenza Viruses Target Different Human Proteins and Pathways Leading to Different Pathogenic Phenotypes

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Yujie Wang ◽  
Ting Song ◽  
Kaiwu Li ◽  
Yuan Jin ◽  
Junjie Yue ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Influenza A ◽  
Viral Proteins ◽  
Influenza Viruses ◽  
Host Protein ◽  
Protein Protein Interactions ◽  
Influenza A Viruses ◽  
Host Proteins ◽  
Pathogenic Mechanisms ◽  
Human Proteins

Different subtypes of influenza A viruses (IAVs) cause different pathogenic phenotypes after infecting human bodies. Analysis of the interactions between viral proteins and the host proteins may provide insights into the pathogenic mechanisms of the virus. In this paper, we found that the same proteins (nucleoprotein and neuraminidase) of H1N1 and H5N1 have different impacts on the NF-κB activation. By further examining the virus–host protein–protein interactions, we found that both NP and NA proteins of the H1N1 and H5N1 viruses target different host proteins. These results indicate that different subtypes of influenza viruses target different human proteins and pathways leading to different pathogenic phenotypes.

scholarly journals Functional and Genetic Studies of the Substrate Specificity of Coronavirus Infectious Bronchitis Virus 3C-Like Proteinase

2010 ◽  
Vol 84 (14) ◽  
pp. 7325-7336 ◽  
Author(s):  
Shouguo Fang ◽  
Hongyuan Shen ◽  
Jibin Wang ◽  
Felicia P. L. Tay ◽  
Ding Xiang Liu
Keyword(s):  
Infectious Bronchitis Virus ◽  
Nonstructural Protein ◽  
Cleavage Sites ◽  
Nonstructural Proteins ◽  
Genetic Studies ◽  
Subgenomic Rna ◽  
Infectious Bronchitis ◽  
Growth Defects ◽  
Cleavage Efficiency

ABSTRACT Coronavirus (CoV) 3C-like proteinase (3CLpro), located in nonstructural protein 5 (nsp5), processes the replicase polyproteins 1a and 1ab (pp1a and pp1ab) at 11 specific sites to produce 12 mature nonstructural proteins (nsp5 to nsp16). Structural and biochemical studies suggest that a conserved Gln residue at the P1 position is absolutely required for efficient cleavage. Here, we investigate the effects of amino acid substitution at the P1 position of 3CLpro cleavage sites of infectious bronchitis virus (IBV) on the cleavage efficiency and viral replication by in vitro cleavage assays and reverse genetic approaches. Our results demonstrated that a P1-Asn substitution at the nsp4-5/Q2779, nsp5-6/Q3086, nsp7-8/Q3462, nsp8-9/Q3672, and nsp9-10/Q3783 sites, a P1-Glu substitution at the nsp8-9/Q3672 site, and a P1-His substitution at the nsp15-16/Q6327 site were tolerated and allowed recovery of infectious mutant viruses, albeit with variable degrees of growth defects. In contrast, a P1-Asn substitution at the nsp6-7/Q3379, nsp12-13/Q4868, nsp13-14/Q5468, and nsp14-15/Q5989 sites, as well as a P1-Pro substitution at the nsp15-16/Q6327 site, abolished 3CLpro-mediated cleavage at the corresponding position and blocked the recovery of infectious viruses. Analysis of the effects of these lethal mutations on RNA synthesis suggested that processing intermediates, such as the nsp6-7, nsp12-13, nsp13-14, nsp14-15, and nsp15-16 precursors, may function in negative-stranded genomic RNA replication, whereas mature proteins may be required for subgenomic RNA (sgRNA) transcription. More interestingly, a mutant 3CLpro with either a P166S or P166L mutation was selected when an IBV infectious cDNA clone carrying the Q6327N mutation at the nsp15-16 site was introduced into cells. Either of the two mutations was proved to enhance significantly the 3CLpro-mediated cleavage efficiency at the nsp15-16 site with a P1-Asn substitution and compensate for the detrimental effects on recovery of infectious virus.

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