p16 INK4a Gene Promoter Variation and Differential Binding of a Repressor, the Ras-Responsive Zinc-Finger Transcription Factor, RREB

Oncogene. 2003 Apr 17;22(15):2285-95. doi: 10.1038/sj.onc.1206257.

Abstract

BALB/c mice are susceptible to the development of pristane-induced plasma cell tumors, and have a rare allelic variant in the coding region of the p16(INK4a) (p16) tumor suppressor gene that produces a protein with impaired activity. We have now found that the BALB/c p16 promoter has an allelic variant that may also compromise p16 activity. Following pristane treatment, BALB/c p16 mRNA levels in B cells were lower than that in DBA/2 or C.D2-Pctr1, a resistant BALB/c congenic strain that harbors DBA/2 chromatin surrounding the p16 locus. Four sequence variants were found between BALB/c and DBA/2 in the p16 promoter region. In reporter assays, the DBA promoter was at least four times more active in driving luciferase expression than the BALB/c promoter. Most of the difference in activity was localized to a single nucleotide deletion in BALB/c. This deletion created a consensus binding site for RREB, a ras-responsive transcriptional element with zinc-finger binding motifs. Transient transfections with RREB confirmed that the p16 promoter can be downregulated by RREB, in a Ras- or Mek-dependent manner, and that the BALB/c promoter is more sensitive than DBA/2 to regulation by RREB. BALB/c mice have both regulatory and coding region defects that may contribute to the impairment of p16 gene function.

Publication types

  • Comparative Study

MeSH terms

  • 3T3 Cells
  • Alleles
  • Animals
  • Animals, Congenic
  • B-Lymphocytes / metabolism
  • Binding Sites
  • Consensus Sequence
  • DNA Mutational Analysis
  • DNA-Binding Proteins / physiology*
  • Gene Expression Regulation / drug effects
  • Gene Expression Regulation / genetics
  • Genes, Reporter
  • Genes, p16*
  • Genetic Predisposition to Disease
  • Genetic Variation
  • Luciferases / biosynthesis
  • Luciferases / genetics
  • MAP Kinase Kinase 1
  • Mice
  • Mice, Inbred BALB C / genetics*
  • Mice, Inbred DBA / genetics*
  • Mitogen-Activated Protein Kinase Kinases / physiology
  • Plasmacytoma / genetics
  • Promoter Regions, Genetic / genetics*
  • Protein-Serine-Threonine Kinases / physiology
  • RNA, Messenger / biosynthesis
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / genetics
  • Species Specificity
  • Spleen / metabolism
  • Terpenes / pharmacology
  • Transcription Factors / physiology*
  • Transfection
  • ras Proteins / physiology

Substances

  • DNA-Binding Proteins
  • RNA, Messenger
  • RREB1 protein, human
  • Recombinant Fusion Proteins
  • Terpenes
  • Transcription Factors
  • pristane
  • Luciferases
  • Protein-Serine-Threonine Kinases
  • MAP Kinase Kinase 1
  • MAP2K1 protein, human
  • Map2k1 protein, mouse
  • Mitogen-Activated Protein Kinase Kinases
  • ras Proteins