title: Conserved nucleotides in the terminus of the 3' UTR region are important for the replication and infectivity of porcine reproductive and respiratory syndrome virus.
abstract: The 3' untranslated region (3' UTR), including the poly (A) tail, reportedly plays an important role in arterivirus replication, but the roles of the cis-acting elements present in the 3' UTR of porcine reproductive and respiratory syndrome virus (PRRSV) remain largely unknown. In the present study, PCR-based mutagenic analysis was conducted on the 3' UTR of PRRSV infectious full-length cDNA clone pAPRRS to investigate the structure and function of the conserved terminal nucleotides between the poly (A) tail and the 3' UTR region. Our findings indicated that the conservation of the primary sequence of the 3' terminal nucleotides, rather than the surrounding secondary structure, was vital for viral replication and infectivity. Four nucleotides (nt) (5'-(15517)AAUU(15520)-3') at the 3' proximal end of the 3' UTR and the dinucleotide 5'-AU-3' exerted an important regulatory effect on viral viability. Of the five 3'-terminal nucleotides of the 3' UTR (5'-(15503)AACCA(15507)-3'), at least three, including the last dinucleotide (5'-CA-3'), were essential for maintaining viral infectivity. Taken together, the 3'-terminal conserved sequence plays a critical role in PRRSV replication and may function as a contact site for specific assembly of the replication complex.
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 518, Ziyue Road, Minhang District, Shanghai 200241, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yin
authors.forename: Changlong
authors.initials: C
authors.lastname: Liu
authors.forename: Ping
authors.initials: P
authors.lastname: Liu
authors.forename: Huochun
authors.initials: H
authors.lastname: Yao
authors.forename: Zuzhang
authors.initials: Z
authors.lastname: Wei
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Lu
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Tong
authors.forename: Fei
authors.initials: F
authors.lastname: Gao
authors.forename: Shishan
authors.initials: S
authors.lastname: Yuan
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D002460:Cell Line; D017124:Conserved Sequence; D004252:DNA Mutational Analysis; D016133:Polymerase Chain Reaction; D019316:Porcine respiratory and reproductive syndrome virus / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D014779:Virus Replication
chemical_list: D020413:3' Untranslated Regions