Characterization of the hepatitis B virus X- and nucleocapsid gene transcriptional regulatory elements

Virology. 1992 Nov;191(1):31-41. doi: 10.1016/0042-6822(92)90163-j.

Abstract

The regulatory DNA sequence elements that control the expression of the hepatitis B virus X- and nucleocapsid genes in the differentiated human hepatoma cell lines, Huh7, Hep3B, PLC/PRF/5, and HepG2, the dedifferentiated human hepatoma cell line, HepG2.1, and the human cervical carcinoma cell line, HeLa S3, were analyzed using transient transfection assays. In this system, the hepatitis B virus enhancer I located between coordinates 1071 (-239) and 1238 (-72) increases transcription from the X-gene promoter located between coordinates 1239 (-71) and 1376 (+67) more than 30-fold in the differentiated hepatoma and the HeLa S3 cell lines. In the dedifferentiated hepatoma cell line, HepG2.1, the enhancer I sequence increases the level of transcription from the X-gene promoter approximately 10-fold. The enhancer I subregion between coordinates 1117 (-193) and 1204 (-106) appears to be important for enhancer function only in the differentiated hepatoma cell lines, whereas the enhancer I subregion between coordinates 1222 (-88) and 1238 (-72) is required for enhancer activity in each of the cell lines examined. In all of the cell lines, the X-gene minimal promoter element was within a 138-nucleotide sequence located between coordinates 1239 (-71) and 1376 (+67). The enhancer I sequence increases transcription from the nucleocapsid promoter approximately 3- to 10-fold in the Huh7, Hep3B, PLC/PRF/5, and HeLa S3 cell lines, whereas it had little influence on the level of transcription from this promoter in HepG2 and HepG2.1 cells. The minimal nucleocapsid promoter element was within a 105 nucleotide sequence located between coordinates 1700 (-85) and 1804 (+20). This indicates that the levels of transcription from the X- and nucleocapsid gene promoters are determined in a cell-type-specific manner, in part, by the hepatitis B virus enhancer I and the corresponding minimal promoter sequence.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Base Sequence
  • DNA, Viral
  • Enhancer Elements, Genetic
  • Hepatitis B virus / genetics*
  • Humans
  • Molecular Sequence Data
  • Promoter Regions, Genetic
  • Regulatory Sequences, Nucleic Acid*
  • Sequence Deletion
  • Trans-Activators / genetics*
  • Transcription, Genetic*
  • Tumor Cells, Cultured
  • Viral Core Proteins / genetics*

Substances

  • DNA, Viral
  • Trans-Activators
  • Viral Core Proteins
  • hepatitis B virus X protein