Transcription factor AP-4 is a ligand for immunoglobulin-κ promoter E-box elements

Research output: Contribution to journalArticle

Abstract

Immunoglobulin (Ig)-κ promoters from humans and mice share conserved sequences. The octamer element is common to all Ig promoters and pivotal for their function. However, other conserved sequence motifs, that differ between lg variable gene families, are required for normal promoter function. These conserved motifs do not stimulate transcription in the absence of an octamer. One example is an E-box of the E47/E12 type (5′-CAGCTG-3′), which is found in all promoters of the human and murine Ig-κ gene subgroups/families, with the exception of subgroups II and VI and their related murine families. In the present study we show that the ubiquitously expressed transcription factor AP-4, and not E47, interacts specifically with the κ promoter E-boxes when tested in electrophoretic mobility-shift assays using nuclear extracts derived from human and murine B-cell lines. Furthermore, AP-4, unlike E47, did not act as a transactivator, which is in agreement with previous studies on intact κ promoters, showing that transcription is absent when the octamer element has been mutated. Based on these data, and the conservation of the 5′-CAGCTG-3′ motif among human and murine κ promoters, we propose that AP-4 is the major ligand for Ig-κ promoter E-boxes.

Details

Authors
Organisations
External organisations
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Immunology in the medical area
  • Cell and Molecular Biology

Keywords

  • bHLH-Zip protein, Conserved sequences, Immunoglobulin genes
Original languageEnglish
Pages (from-to)431-438
Number of pages8
JournalBiochemical Journal
Volume354
Issue number2
Publication statusPublished - 2001 Mar 1
Publication categoryResearch
Peer-reviewedYes