Identification of amino acid residues important for anti-IFN activity of porcine reproductive and respiratory syndrome virus non-structural protein 1

In this study, we compared the genetic mutation and virulence of the attenuated PRRSV strains obtained by 95 serial passages in Marc-145 cells with the parental virulent strain (designated as BG81) isolated in Vietnam. Results showed that there were marked changes in virulence: pigs inoculated with BG81 exhibited high fever ( 41◦C), which lasted for 12 days, and presented typical clinical symptoms of PRRSV; otherwise, pigs inoculated with BG895 (from passage 95), maintained mean rectal temperature from 39,5oC to 39,9oC, did not develop any significant clinical symptoms. Whole genomes of the attenuated strains were significantly different, but their sequence lengths were conserved, i.e., 15,321 nucleotides. The attenuated strain from passage 95 (BG895) contained 38 nucleotide substitutions that resulted in 14 amino acid changes. Most of these changes (about 65%) occurred before passage 50. The 14 amino acid changes were distributed in Nsp1, Nsp4, Nsp9, Nsp10, GP2, E, GP3, GP4, GP5 and N. Specially, there were two single substitutes within a codon in ORF3, corresponding to parallel mutation at position F143L. However, structural protein (M) and eight non-structural proteins (Nsp2, Nsp3, Nsp5, Nsp6, Nsp7, Nsp8, Nsp11 and Nsp12) among the 19 PRRSV proteins, remained conserved, without any mutations and supposed for consideration as irrelative to the attenuation process. It is interesting that in the gene coding for the smallest structural protein (E protein), there was the highest mutation rate among all of the structural genes analyzed, and genetically, seemed to be a highly variable region. These changes may provide the molecular bases for the observation of the attenuated phenotype in pigs. Thus, our variation results obtained between the attenuated BG895 and the parental virulent BG81 strains provide appropriate molecular data for potential use to test and control the masterseed strain in production of a PRRSV vaccine in Vietnam.

Download Full-text

Identification of Major Histocompatibility Complex Restriction and Anchor Residues of Foot-and-Mouth Disease Virus-Derived Bovine T-Cell Epitopes

Journal of Virology ◽

10.1128/jvi.01534-08 ◽

2009 ◽

Vol 83 (9) ◽

pp. 4039-4050 ◽

Cited By ~ 18

Author(s):

Wilhelm Gerner ◽

Sabine E. Hammer ◽

Karl-Heinz Wiesmüller ◽

Armin Saalmüller

Keyword(s):

Major Histocompatibility Complex ◽

Amino Acid ◽

Mhc Class Ii ◽

Foot And Mouth Disease ◽

Amino Acid Residues ◽

T Cell Epitopes ◽

Structural Protein ◽

Histocompatibility Complex ◽

Mouth Disease Virus ◽

Proliferation Assays

ABSTRACT Despite intensive research on the identification of T-cell epitopes in cattle after foot-and-mouth disease virus (FMDV) infection during the last 20 years, knowledge of major histocompatibility complex (MHC) restriction and anchor residues of such epitopes is still sparse. Therefore, as a first step, we tested lymphocytes from two experimentally FMDV serotype A24-vaccinated and -challenged cattle for recognition of FMDV-derived pentadecapeptides in proliferation assays. Two epitopes were identified: amino acid residues 66 to 80 within the structural protein 1D and amino acid residues 22 to 36 within the structural protein 1A. The latter epitope was recognized by lymphocytes from both cattle. Peptide-specific proliferation was caused by a response of CD4+ T helper cells as identified by carboxyfluorescein diacetate succinimidyl ester proliferation assays. Having identified one epitope that was recognized by two cattle, we hypothesized that these animals should have common MHC class II alleles. Cloning and sequencing of DRB3, DQA, and DQB alleles revealed that both animals possessed DQA allele 22021 and DQB allele 1301 but had no common DRB3 allele. A parallel analysis of amino acid residues involved in MHC presentation by peptides with alanine substitutions showed that the amino acid residues in positions 5 and 9 within the pentadecapeptide representing the 1A epitope were important for MHC binding in both cattle. These data indicate that the epitope located on FMDV protein 1A can be presented by MHC class II DQ molecules encoded by DQA allele 22021 and DQB allele 1301 and present the first evidence of the binding motif of this particular DQ molecule.

Download Full-text

A Crystal Structure of the Dengue Virus Non-structural Protein 5 (NS5) Polymerase Delineates Interdomain Amino Acid Residues That Enhance Its Thermostability andde NovoInitiation Activities

Journal of Biological Chemistry ◽

10.1074/jbc.m113.508606 ◽

2013 ◽

Vol 288 (43) ◽

pp. 31105-31114 ◽

Cited By ~ 53

Author(s):

Siew Pheng Lim ◽

Jolene Hong Kiew Koh ◽

Cheah Chen Seh ◽

Chong Wai Liew ◽

Andrew D. Davidson ◽

...

Keyword(s):

Crystal Structure ◽

Amino Acid ◽

Dengue Virus ◽

Amino Acid Residues ◽

Structural Protein

Download Full-text

The amino acid residues at 102 and 104 in GP5 of porcine reproductive and respiratory syndrome virus regulate viral neutralization susceptibility to the porcine serum neutralizing antibody

Virus Research ◽

10.1016/j.virusres.2015.04.015 ◽

2015 ◽

Vol 204 ◽

pp. 21-30 ◽

Cited By ~ 18

Author(s):

Baochao Fan ◽

Xing Liu ◽

Juan Bai ◽

Tingjie Zhang ◽

Qiaoya Zhang ◽

...

Keyword(s):

Amino Acid ◽

Neutralizing Antibody ◽

Respiratory Syndrome Virus ◽

Amino Acid Residues ◽

Viral Neutralization ◽

Porcine Serum

Download Full-text

Primary structure of a structural protein from the cuticle of the migratory locust, Locusta migratoria

Biochemical Journal ◽

10.1042/bj2360713 ◽

1986 ◽

Vol 236 (3) ◽

pp. 713-720 ◽

Cited By ~ 42

Author(s):

P Højrup ◽

S O Andersen ◽

P Roepstorff

Keyword(s):

Amino Acid ◽

Primary Structure ◽

Locusta Migratoria ◽

Protein A ◽

Complete Sequence ◽

Amino Acid Residues ◽

Structural Protein ◽

Migratory Locust ◽

Common Amino Acid ◽

Conserved Sequence

The complete amino acid sequence of a structural protein isolated from pharate cuticle of the locust Locusta migratoria was determined. The protein has an unusual amino acid composition: 42% of the residues are alanine and only 14 of the 20 common amino acid residues are present. The primary structure consists of regions enriched in particular amino acid residues. The N-terminal region and a region close to the C-terminus are enriched in glycine. The rest of the protein is dominated by alanine, except for two short regions enriched in hydrophilic residues. Almost all the proline residues are situated in the alanine-rich regions in a conserved sequence ‘A-A-P-A/V’. An internal duplication has taken place covering most of the protein except for the glycine-rich regions. Owing to the unusual features of the protein a combination of automated Edman degradations and plasma-desorption m.s. was used to determine the complete sequence. The protein does not show sequence homology to other proteins, but proteins divided into regions enriched in the same kind of amino acid residues have been isolated from other insect structures.

Download Full-text