Chemoselective Modification of Viral Proteins Bearing Metabolically Introduced “Clickable” Amino Acids and Sugars

2011 ◽  
pp. 55-66 ◽  
Author(s):  
Partha S. Banerjee ◽  
Isaac S. Carrico
Keyword(s):  
Amino Acids ◽  
Viral Proteins

scholarly journals Cimodo virus belongs to a novel lineage of reoviruses isolated from African mosquitoes

2014 ◽  
Vol 95 (4) ◽  
pp. 905-909 ◽  
Author(s):  
Kyra Hermanns ◽  
Florian Zirkel ◽  
Andreas Kurth ◽  
Christian Drosten ◽  
Sandra Junglen
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Liquid Chromatography ◽  
Cote D'ivoire ◽  
Côte D’Ivoire ◽  
Viral Proteins ◽  
Liquid Chromatography Mass Spectrometry ◽  
Entire Genome ◽  
Cote D’Ivoire ◽  
Chromatography Mass Spectrometry

A novel reovirus, designated Cimodo virus (CMDV), was isolated from mosquitoes collected in a rainforest region in Côte d’Ivoire. The entire genome comprised 24 835 bp divided into 12 segments ranging from 585 to 4080 bp. The icosahedral non-enveloped virions were 80 nm in diameter. Eight major viral proteins of about 150, 135, 120, 80, 66, 59, 42 and 30 kDa were identified and seven proteins were mapped to the corresponding genome segments by liquid chromatography mass spectrometry. Predicted protein genes diverged by >77 % encoded amino acids from their closest reovirus relatives. The deep phylogenetic branching suggests that CMDV defines an as-yet-unidentified genus within the subfamily Spinareovirinae.

Rapid “tea-bag” peptide synthesis using 9-fluorenylmethoxycarbonyl (Fmoc) protected amino acids applied for antigenic mapping of viral proteins

1991 ◽  
Vol 30 (1) ◽  
pp. 59-68 ◽  
Author(s):  
Matti Sällberg ◽  
Ulla Rudén ◽  
Lars O. Magnius ◽  
Erling Norrby ◽  
Britta Wahren
Keyword(s):  
Amino Acids ◽  
Peptide Synthesis ◽  
Viral Proteins

scholarly journals Equine infectious anaemia virus proteins with epitopes most frequently recognized by cytotoxic T lymphocytes from infected horses

2000 ◽  
Vol 81 (11) ◽  
pp. 2735-2739 ◽  
Author(s):  
Travis C. McGuire ◽  
Steven R. Leib ◽  
Scott M. Lonning ◽  
Wei Zhang ◽  
Katherine M. Byrne ◽  
...  
Keyword(s):  
Amino Acids ◽  
T Lymphocytes ◽  
Mhc Class I ◽  
Cytotoxic T Lymphocytes ◽  
Viral Proteins ◽  
Retroviral Vector ◽  
Target Cells ◽  
Outbred Populations ◽  
Equine Infectious Anaemia Virus ◽  
Mhc Class I Molecules

Efficacious lentiviral vaccines designed to induce cytotoxic T lymphocytes (CTL) in outbred populations with a diverse repertoire of MHC class I molecules should contain or express multiple viral proteins. To determine the equine infectious anaemia virus (EIAV) proteins with epitopes most frequently recognized by CTL from seven horses infected for 0·5 to 7 years, retroviral vector-transduced target cells expressing viral proteins were used in CTL assays. Gag p15 was recognized by CTL from 100% of these infected horses. p26 was recognized by CTL from 86%, SU and the middle third of Pol protein were each recognized by 43%, TM by 29%, and S2 by 14%. Based on these results, it is likely that a construct expressing the 359 amino acids constituting p15 and p26 would contain epitopes capable of stimulating CTL in most horses.

scholarly journals Interaction between the Human Cytomegalovirus Tegument Proteins UL94 and UL99 Is Essential for Virus Replication

2012 ◽  
Vol 86 (18) ◽  
pp. 9995-10005 ◽  
Author(s):  
Stacia L. Phillips ◽  
Daniel Cygnar ◽  
Alexandra Thomas ◽  
Wade A. Bresnahan
Keyword(s):  
Amino Acids ◽  
Human Cytomegalovirus ◽  
Infectious Virus ◽  
Viral Proteins ◽  
Tegument Protein ◽  
Dependent Manner ◽  
Tegument Proteins ◽  
Cytoplasmic Structure ◽  
Infected Cells ◽  
Secretory Apparatus

Human cytomegalovirus (HCMV) virions are structurally complex, and the mechanisms by which they are assembled are poorly understood, especially with respect to the cytoplasmic phase of assembly, during which the majority of the tegument is acquired and final envelopment occurs. These processes occur at a unique cytoplasmic structure called the assembly complex, which is formed through a reorganization of the cellular secretory apparatus. The HCMV tegument protein UL99 (pp28) is essential for viral replication at the stage of secondary envelopment. We previously demonstrated that UL99 interacts with the essential tegument protein UL94 in infected cells as well as in the absence of other viral proteins. Here we show that UL94 and UL99 alter each other's localization and that UL99 stabilizes UL94 in a binding-dependent manner. We have mapped the interaction between UL94 and UL99 to identify the amino acids of each protein that are required for their interaction. Mutation of these amino acids in the context of the viral genome demonstrates that HCMV is completely defective for replication in the absence of the interaction between UL94 and UL99. Further, we demonstrate that in the absence of their interaction, both UL94 and UL99 exhibit aberrant localization and do not accumulate at the assembly complex during infection. Taken together, our data suggest that the interaction between UL94 and UL99 is essential for the proper localization of each protein to the assembly complex and thus for the production of infectious virus.

scholarly journals The Phosphorylation Status of the Serine-Rich Region of the Human Cytomegalovirus 86-Kilodalton Major Immediate-Early Protein IE2/IEP86 Affects Temporal Viral Gene Expression

2005 ◽  
Vol 79 (3) ◽  
pp. 1428-1437 ◽  
Author(s):  
M. Inmaculada Barrasa ◽  
Noam Y. Harel ◽  
James C. Alwine
Keyword(s):  
Amino Acids ◽  
Human Cytomegalovirus ◽  
Viral Proteins ◽  
Immediate Early ◽  
Gene Promoters ◽  
Temporal Expression ◽  
Rich Region ◽  
Virus Growth ◽  
Early Protein

ABSTRACT The 86-kDa major immediate-early protein (IE2/IEP86) of human cytomegalovirus (HCMV) contains a serine-rich region (amino acids 258 to 275) with several consensus casein kinase II (CKII) sites. We performed extensive mutational analysis of this region, changing serines to alternating alanines and glycines. Mutation of the serines between amino acids 266 and 275 eliminated in vitro phosphorylation by CKII. In vitro CKII phosphorylation of the serines between amino acids 266 and 269 or between amino acids 271 and 275 inhibited the ability of IE2/IEP86 to bind to TATA-binding protein. Correspondingly, nonphosphorylatable mutants in these regions showed increased activation of specific HCMV gene promoters in transfection studies. Viruses containing mutations of the serines throughout the entire region (amino acids 258 to 275) or the second half (amino acids 266 to 275) of the region showed delayed expression of all viral proteins tested and, correspondingly, delayed growth compared to wild-type HCMV. Mutation of the serines in the first half of the serine-rich region (amino acids 258 to 264) or between amino acids 266 and 269 propagated very slowly and has not been further studied. In contrast, mutation of the serines between amino acids 271 and 275 resulted in accelerated virus growth and accelerated temporal expression of viral proteins. These results suggest that the serine-rich region is structurally complex, possibly affecting multiple functions of IE2/IEP86. The data show that the phosphorylation state of the serine-rich region, particularly between amino acids 271 and 275, modulates the temporal expression of viral genes.

scholarly journals Molecular coevolution of nuclear and nucleolar localization signals inside basic domain of HIV-1 Tat

2021 ◽  
Author(s):  
Margarita A. Kurnaeva ◽  
Arthur O. Zalevsky ◽  
Eugene A. Arifulin ◽  
Olga M. Lisitsyna ◽  
Anna V. Tvorogova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Viral Proteins ◽  
Nucleolar Localization ◽  
Functional Domains ◽  
Small Protein ◽  
Basic Domain ◽  
Protein Size ◽  
Charged Amino Acids ◽  
Hiv 1 ◽  
Positively Charged

During evolution, viruses had to adapt to an increasingly complex environment of eukaryotic cells. Viral proteins that need to enter the cell nucleus or associate with nucleoli possess nuclear localization signals (NLSs) and nucleolar localization signals (NoLSs) for nuclear and nucleolar accumulation, respectively. As viral proteins are relatively small, acquisition of novel sequences seems to be a more complicated task for viruses than for eukaryotes. Here, we carried out a comprehensive analysis of the basic domain (BD) of HIV-1 Tat to show how viral proteins might evolve with NLSs and NoLSs without an increase in protein size. The HIV-1 Tat BD is involved in several functions, the most important being the transactivation of viral transcription. The BD also functions as an NLS, although it is substantially longer than a typical NLS. It seems that different regions in the BD could function as NLSs due to its enrichment with positively charged amino acids. Additionally, the high positive net charge inevitably causes the BD to function as an NoLS through a charge-specific mechanism. The integration of NLSs and NoLSs into functional domains enriched with positively charged amino acids might be a mechanism that allows the condensation of different functional sequences in small protein regions and, as a result, to reduce protein size, influencing the origin and evolution of NLSs and NoLSs in viruses. IMPORTANCE Here, we investigated the molecular mechanism of NLS and NoLS integration into the basic domain of HIV-1 Tat ( 49 RKKRRQRRR 57 ), and found that these two supplementary functions (i.e., function of NLS and NoLS) are embedded in the basic domain amino acid sequence. The integration of NLSs and NoLSs into functional domains of viral proteins enriched with positively charged amino acids is a mechanism that allows the concentration of different functions within small protein regions. Integration of NLS and NoLS into functional protein domains might have influenced the viral evolution, as this could prevent an increase in the protein size.

scholarly journals Mechanisms and evolutionary implications of integration of different functions within HIV-1 Tat

2021 ◽  
Author(s):  
Margarita A. Kurnaeva ◽  
Arthur O. Zalevsky ◽  
Eugene A. Arifulin ◽  
Olga M. Lisitsyna ◽  
Anna V. Tvorogova ◽  
...  
Keyword(s):  
Amino Acids ◽  
Viral Proteins ◽  
Net Charge ◽  
Origin And Evolution ◽  
Nuclear Localization Signals ◽  
Protein Size ◽  
Charged Amino Acids ◽  
A Charge ◽  
Hiv 1 ◽  
Positively Charged

During evolution, viruses had to adapt to an increasingly complex environment of eukaryotic cells. Viral proteins that need to enter the cell nucleus or associate with nucleoli possess nuclear localization signals (NLSs) and nucleolar localization signals (NoLSs) for nuclear and nucleolar accumulation, respectively. As viral proteins are relatively small, acquisition of novel sequences seems to be a more complicated task for viruses than for eukaryotes. Here, we carried out a comprehensive analysis of the basic domain (BD) of HIV-1 Tat to show how viral proteins might evolve with NLSs and NoLSs without an increase in protein size. The HIV-1 Tat BD is involved in several functions, the most important being the transactivation of viral transcription. The BD also functions as an NLS, although it is substantially longer than a typical NLS. It seems that different regions in the BD could function as NLSs due to its enrichment with positively charged amino acids. Additionally, the high positive net charge inevitably causes the BD to function as an NoLS through a charge-specific mechanism. The integration of NLSs and NoLSs into functional domains enriched with positively charged amino acids might be a mechanism that allows the condensation of different functional sequences in small protein regions and, as a result, to reduce protein size, influencing the origin and evolution of NLSs and NoLSs in viruses.

scholarly journals Proline and Tyrosine Residues in Scaffold Proteins of Herpes Simplex Virus 1 Critical to the Interaction with Portal Protein and Its Incorporation into Capsids

2009 ◽  
Vol 83 (16) ◽  
pp. 8076-8081 ◽  
Author(s):  
Kui Yang ◽  
Joel D. Baines
Keyword(s):  
Amino Acids ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Direct Interaction ◽  
Viral Proteins ◽  
Scaffold Proteins ◽  
Herpes Simplex Virus 1 ◽  
Portal Protein ◽  
Pulldown Assay ◽  
Simplex Virus

ABSTRACT Previous results showed that amino acids 449 to 457 of pUL26, a component of the scaffold of herpes simplex virus 1 capsids, were critical for interaction with the portal protein encoded by UL6 and for incorporation of the portal into capsids. To identify residues in this scaffold domain critical for the interaction with pUL6, the two proteins were coexpressed in the absence of other viral proteins and subjected to immunoprecipitation with scaffold-specific antibody. Coimmunoprecipitation of pUL6 was precluded by pUL26 mutations Y451A, P452A, and E454A but not by P449A, R456A, or Y450A. In infected cells, Y451A and P452A diminished solubilization of pUL6, reduced incorporation of the portal into the capsid, and precluded viral replication and DNA packaging. In contrast, E454A did not affect these parameters despite the fact that E454 is invariant in a number of different alphaherpesvirus scaffold proteins. These data suggest that the interaction between the scaffold E454A mutant and portal protein is rescued by other viral functions. Finally, we show that amino acids 448 to 459 of pUL26 are sufficient to interact with pUL6 in a glutathione S-transferase pulldown assay in the absence of other viral proteins and that this interaction is inhibited with excess peptide containing pUL26 amino acids 443 to 462. Together, these observations suggest that a direct interaction between this scaffold domain and portal protein mediates incorporation of the portal into the capsid.

scholarly journals Mutation of the Tobacco Mosaic Tobamovirus 126-and 183-kDa Proteins: Effects on Phloem-Dependent Virus Accumulation and Synthesis of Viral Proteins

1997 ◽  
Vol 10 (5) ◽  
pp. 589-596 ◽  
Author(s):  
Peter M. Derrick ◽  
Shelly A. Carter ◽  
Richard S. Nelson
Keyword(s):  
Amino Acids ◽  
Host Response ◽  
Movement Protein ◽  
Viral Proteins ◽  
Coat Proteins ◽  
Functional Competence ◽  
Movement Proteins ◽  
The Difference ◽  
Virus Coat ◽  
Symptom Phenotype

The masked and U1 strains of tobacco mosaic tobamovirus differ in symptom phenotype and in phloem-dependent accumulation in tobacco. The symptom phenotype is determined by eight amino acids in the 126- and 183-kDa proteins that differ between the two strains. In this study, slow phloem-dependent accumulation of the masked strain was shown to be determined by these same eight amino acids, but some symptomatically severe mutants altered at specific positions within the eight amino acids were inefficient in phloem-dependent accumulation. Therefore, the appearance of severe symptoms does not require rapid phloem-dependent accumulation. There was no consistent relationship between the accumulation of virus coat protein, movement protein, or 126- and 183-kDa protein in inoculated protoplasts and the efficiency of phloem-dependent accumulation in stem tissue. Therefore, the difference in phloem-dependent accumulation between the masked strain, its mutants, and the U1 strain in most instances resulted from the functional competence of the 126- and/or 183-kDa proteins or a host response to their change and not from their quantities or the quantities or functional competence of the movement proteins or coat proteins.

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