Characterization of the Role of Hexamer AGUAAA and Poly(A) Tail in Coronavirus Polyadenylation

• Published in: PloS one Vol. 11; no. 10; p. e0165077
• Main Authors: Peng, Yu-Hui, Lin, Ching-Houng, Lin, Chao-Nan, Lo, Chen-Yu, Tsai, Tsung-Lin, Wu, Hung-Yi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 19.10.2016; Public Library of Science (PLoS)
• Subjects: Biology and life sciences; Cell Line; Cloning; Coronaviridae; Coronavirus - genetics; Coronavirus - pathogenicity; Coronavirus Infections - virology; Coronaviruses; COVID-19; Deoxyribonucleic acid; DNA; Efficiency; Gene expression; Genetic Variation; Genomes; Genomics; Health aspects; Humans; Infection; Infections; Medicine and Health Sciences; Messenger RNA; mRNA; Mutagenesis; Mutation; Nucleotides; Poly(A); Polyadenine; Polyadenylation; Proteins; Research and analysis methods; RNA, Messenger - genetics; RNA, Viral - genetics; Veterinary colleges; Veterinary medicine; Virology; Viruses; United States > US; Taiwan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0165077

Similar to eukaryotic mRNA, the positive-strand coronavirus genome of ~30 kilobases is 5'-capped and 3'-polyadenylated. It has been demonstrated that the length of the coronaviral poly(A) tail is not static but regulated during infection; however, little is known regarding the factors involved in coronaviral polyadenylation and its regulation. Here, we show that during infection, the level of coronavirus poly(A) tail lengthening depends on the initial length upon infection and that the minimum length to initiate lengthening may lie between 5 and 9 nucleotides. By mutagenesis analysis, it was found that (i) the hexamer AGUAAA and poly(A) tail are two important elements responsible for synthesis of the coronavirus poly(A) tail and may function in concert to accomplish polyadenylation and (ii) the function of the hexamer AGUAAA in coronaviral polyadenylation is position dependent. Based on these findings, we propose a process for how the coronaviral poly(A) tail is synthesized and undergoes variation. Our results provide the first genetic evidence to gain insight into coronaviral polyadenylation.