Expression of the protein product of the mouse mammary tumor virus long terminal repeat gene in phorbol ester-treated mouse T-cell-leukemia cells

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

Exposure of C57BL/6 mouse EL-4 T-cell leukemia cells to phorbol ester (12-O-tetradecanoylphorbol-13-acetate) (TPA) induced the synthesis of protein products encoded by the mouse mammary tumor virus (MMTV) long terminal repeat (LTR) region. Analysis of TPA-treated EL-4 cells with antiserum raised against a synthetic peptide predicted by the MMTV LTR open reading frame sequence detected a polypeptide migrating in gels with an apparent weight of 37,000 M(r), as well as three less prominent proteins with apparent molecular weights of 31,000, 34,000, and 39,000. Tryptic peptide analysis established the identity of the immunoprecipitated cellular proteins with the LTR proteins obtained from in vitro translation of MMTV genomic RNA. All four proteins were glycosylated and were derived from one initial nonglycosylated translation product of 21,000 M(r). The 21,000-M(r) apoprotein could be detected after digestion with endoglycosidase F or pretreatment of cells with tunicamycin. Untreated EL-4 cells synthesized three species of MMTV mRNA: 35S, 24S, and 20S. TPA treatment resulted in an increased level of transcription of the three mRNAs and the appearance of a new 1-kilobase mRNA. At least 10 acquired MMTV proviruses are present in the EL-4 genome, and examination of the degree of proviral methylation revealed extensive demethylation. However, no qualitative differences in the state of proviral methylation were apparent between TPA-treated and untreated cells.

Original languageEnglish (US)
Pages (from-to)441-449
Number of pages9
JournalJournal of virology
Volume58
Issue number2
DOIs
StatePublished - 1986

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Insect Science
  • Virology

Fingerprint Dive into the research topics of 'Expression of the protein product of the mouse mammary tumor virus long terminal repeat gene in phorbol ester-treated mouse T-cell-leukemia cells'. Together they form a unique fingerprint.

  • Cite this