title: Construction of a full transcription map of human papillomavirus type 18 during productive viral infection.
abstract: Human papillomavirus type 18 (HPV18) is the second most common oncogenic HPV genotype, responsible for ∼15% of cervical cancers worldwide. In this study, we constructed a full HPV18 transcription map using HPV18-infected raft tissues derived from primary human vaginal or foreskin keratinocytes. By using 5' rapid amplification of cDNA ends (RACE), we mapped two HPV18 transcription start sites (TSS) for early transcripts at nucleotide (nt) 55 and nt 102 and the HPV18 late TSS frequently at nt 811, 765, or 829 within the E7 open reading frame (ORF) of the virus genome. HPV18 polyadenylation cleavage sites for early and late transcripts were mapped to nt 4270 and mainly to nt 7299 or 7307, respectively, by using 3' RACE. Although all early transcripts were cleaved exclusively at a single cleavage site, HPV18 late transcripts displayed the heterogeneity of 3' ends, with multiple minor cleavage sites for late RNA polyadenylation. HPV18 splice sites/splice junctions for both early and late transcripts were identified by 5' RACE and primer walking techniques. Five 5' splice sites (donor sites) and six 3' splice sites (acceptor sites) that are highly conserved in other papillomaviruses were identified in the HPV18 genome. HPV18 L1 mRNA translates a L1 protein of 507 amino acids (aa), smaller than the 568 aa residues previously predicted. Collectively, a full HPV18 transcription map constructed from this report will lead us to further understand HPV18 gene expression and virus oncogenesis.
authors.affiliation: Tumor Virus RNA Biology Section, HIV and AIDS Malignancy Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Wang
authors.forename: Craig
authors.initials: C
authors.lastname: Meyers
authors.forename: Hsu-Kun
authors.initials: HK
authors.lastname: Wang
authors.forename: Louise T
authors.initials: LT
authors.lastname: Chow
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Zheng
mesh_terms: D036022:Capsid Proteins / Q000235:genetics; D002478:Cells, Cultured; D004279:DNA, Viral / Q000235:genetics; D015870:Gene Expression; D016679:Genome, Viral; D052161:Human papillomavirus 18 / Q000235:genetics*; D006801:Humans; D015603:Keratinocytes / Q000821:virology*; D016366:Open Reading Frames; D026723:Polyadenylation; D022821:RNA Splice Sites; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D024363:Transcription Initiation Site; D014158:Transcription, Genetic
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral; D022821:RNA Splice Sites; D012333:RNA, Messenger; D012367:RNA, Viral; C480565:L1 protein, Human papillomavirus type 18