title: Effects of two amino acid substitutions in the capsid proteins on the interaction of two cell-adapted PanAsia-1 strains of foot-and-mouth disease virus serotype O with heparan sulfate receptor.
abstract: BACKGROUND
  Some cell-adapted strains of foot-and-mouth disease virus (FMDV) can utilize heparan sulfate (HS) as a receptor to facilitate viral infection in cultured cells. A number of independent sites on the capsid that might be involved in FMDV-HS interaction have been studied. However, the previously reported residues do not adequately explain HS-dependent infection of two cell-adapted PanAsia-1 strains (O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc) of FMDV serotype O. To identify the molecular determinant(s) for the interaction of O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc with HS receptor, several chimeric viruses and site-directed mutants were generated by using an infectious cDNA of a non-HS-utilizing rescued virus (Cathay topotype) as the genomic backbone. Phenotypic properties of these viruses were determined by plaque assays and virus adsorption and penetration assays in cultured cells.
  
  
  RESULTS
  Only two of the rescued viruses encoding VP0 of O/Tibet/CHA/6/99tc or VP1 of O/Fujian/CHA/9/99tc formed plaques on wild-type Chinese hamster ovary (WT-CHO; HS+) cells, but not on HS-negative pgsD-677 cells. The formation of plaques by these two chimeric viruses on WT-CHO cells could be abolished by the introduction of single amino acid mutations Gln-2080 → Leu in VP2 of O/Tibet/CHA/6/99tc and Lys-1083 → Glu in VP1 of O/Fujian/CHA/9/99tc, respectively. Nonetheless, the introduced mutation Leu-2080 → Gln in VP2 of O/Fujian/CHA/9/99tc for the construction of expectant recombinant plasmid led to non-infectious progeny virus in baby hamster kidney 21 (BHK-21) cells, and the site-directed mutant encoding Glu-1083 → Lys in VP1 of O/Tibet/CHA/6/99tc did not acquire the ability to produce plaques on WT-CHO cells. Significant differences in the inhibition of the infectivity of four HS-utilizing viruses by heparin and RGD-containing peptide were observed in BHK-21 cells. Interestingly, the chimeric virus encoding VP0 of O/Fujian/CHA/9/99tc, and the site-directed mutant encoding Gln-2080 → Leu in VP2 of O/Tibet/CHA/6/99tc could bind to HS, but there was no expression of the 3A protein of these two viruses in WT-CHO cells.
  
  
  CONCLUSIONS
  The results suggest that the cooperation of certain specific amino acid residues in the capsid proteins of these two cell-adapted PanAsia-1 strains is essential for viral infectivity, the heparin affinity and the capability on FMDV-HS interaction.
authors: State Key Laboratory of Veterinary Etiological Biology, OIE/National Foot-and-Mouth Disease Reference Laboratory, Engineering Research Center of Biological Detection of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu 730046, China. baixingwen@caas.cn.
authors: Xingwen
authors: X
authors: Bai
authors: Huifang
authors: H
authors: Bao
authors: Pinghua
authors: P
authors: Li
authors: Wei
authors: W
authors: Wei
authors: Meng
authors: M
authors: Zhang
authors: Pu
authors: P
authors: Sun
authors: Yimei
authors: Y
authors: Cao
authors: Zengjun
authors: Z
authors: Lu
authors: Yuanfang
authors: Y
authors: Fu
authors: Baoxia
authors: B
authors: Xie
authors: Yingli
authors: Y
authors: Chen
authors: Dong
authors: D
authors: Li
authors: Jianxun
authors: J
authors: Luo
authors: Zaixin
authors: Z
authors: Liu
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D016466:CHO Cells; D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics*; D002460:Cell Line; D003062:Codon; D006224:Cricetinae; D003412:Cricetulus; D029544:Foot-and-Mouth Disease Virus / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D006493:Heparin / Q000378:metabolism / Q000494:pharmacology; D006497:Heparan Sulfate / Q000378:metabolism*; D008958:Models, Molecular; D009842:Oligopeptides / Q000494:pharmacology; D016366:Open Reading Frames; D011485:Protein Binding; D011487:Protein Conformation; D011991:Receptors, Virus / Q000378:metabolism*; D065288:Serogroup; D010948:Viral Plaque Assay; D053585:Virus Attachment / Q000187:drug effects; D014779:Virus Replication / Q000187:drug effects
chemical_list: D036022:Capsid Proteins; D003062:Codon; D006493:Heparin; D006497:Heparan Sulfate; D009842:Oligopeptides; D011991:Receptors, Virus; C047981:arginyl-glycyl-aspartic acid