Human papillomavirus type 33 in a tonsillar carcinoma generates its putative E7 mRNA via two E6* transcript species which are terminated at different early region poly(A) sites

J Virol. 1992 May;66(5):3172-8. doi: 10.1128/JVI.66.5.3172-3178.1992.

Abstract

Human papillomavirus type 33 (HPV-33)-specific early region transcripts in a tonsillar carcinoma were analyzed by using the RNA polymerase chain reaction method. A total of five cDNA species including species with potential to encode E6*I, E6*II, and E6*III, could be identified. As determined by 3' cDNA end mapping, one E6*I cDNA species was found to utilize a novel early region poly(A) site and was polyadenylated at or near the putative initiation codon of the E1 open reading frame (ORF). Compared with the HPV-16 and HPV-18 E6* mRNAs, the HPV-33 E6*I and E6*II species utilize different splice acceptor sites, the latter being localized within the E7 ORF. Furthermore, HPV-33 E6* mRNAs were found to contain a short overlapping ORF resulting in alternative coding potentials if translation were to start at an internal AUG codon within the E6 region. These results indicate that like HPV-16 and HPV-18, HPV-33 generates E6* mRNAs which may serve as efficient mRNAs for E7. However, HPV-33 has the ability to generate its putative E7 mRNAs by the utilization of two early region poly(A) sites, which offers the possibility of expressing E7 in different ways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Chromosome Mapping
  • DNA, Single-Stranded
  • Humans
  • Molecular Sequence Data
  • Papillomaviridae / genetics*
  • Poly A
  • Polymerase Chain Reaction
  • RNA Processing, Post-Transcriptional
  • RNA, Messenger / metabolism*
  • Tonsillar Neoplasms / microbiology*
  • Transcription, Genetic*
  • Tumor Virus Infections / genetics*

Substances

  • DNA, Single-Stranded
  • RNA, Messenger
  • Poly A