title: One single nucleotide difference alters the differential expression of spliced RNAs between HBV genotypes A and D.
abstract: Hepatitis B virus (HBV) is generally classified into eight genotypes (A to H) based on genomic sequence divergence. The sequence variation among the different HBV genotypes suggests that the spliced RNAs should be different from genotype to genotype. However, the cis-acting element involved in the modulation of the distinct expression profiles of spliced HBV RNAs remains unidentified. Moreover, the biological role of splicing in the life cycle of HBV is not yet understood. In this study, spliced RNAs generated from genotypes A and D were carefully characterized in transfected HepG2 cells. The species and frequency of the spliced RNAs were dramatically different in the two genotypes. Of note, a population of multiply spliced RNAs with intron 2067-2350 excision was identified in HBV genotype A-transfected HepG2 cells, but not in genotype D transfected HepG2 cells. Further, we found a single nucleotide difference (2335) located within the polypyrimidine tract of the splice acceptor site 2350 between the two genotypes, and a single base substitution at 2335 was able to convert the splicing pattern of genotype D (or genotype A) to that of genotype A (or genotype D). These findings suggest that different unique splice sites may be preferentially used in different HBV genotypes resulting in distinct populations of spliced RNAs. The possible significance of the distinct spliced RNAs generated from the different HBV genotypes in HBV infection is discussed.
authors.affiliation: Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan. camouflage.kiwi@gmail.com
authors.forename: Chien-Chiao
authors.initials: CC
authors.lastname: Huang
authors.forename: Tzer-Min
authors.initials: TM
authors.lastname: Kuo
authors.forename: Chau-Ting
authors.initials: CT
authors.lastname: Yeh
authors.forename: Cheng-Po
authors.initials: CP
authors.lastname: Hu
authors.forename: Ya-Ling
authors.initials: YL
authors.lastname: Chen
authors.forename: Yue-Lin
authors.initials: YL
authors.lastname: Tsai
authors.forename: Mong-Liang
authors.initials: ML
authors.lastname: Chen
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Chou
authors.forename: Chungming
authors.initials: C
authors.lastname: Chang
mesh_terms: D002460:Cell Line; D005838:Genotype; D006515:Hepatitis B virus / Q000235:genetics*; D022781:Hepatocytes / Q000821:virology; D006801:Humans; D020641:Polymorphism, Single Nucleotide; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics*; D012367:RNA, Viral / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D012367:RNA, Viral