The HSS3/4 enhancer of Crlz1-IgJ locus is another target of EBF in the pre-B cell stage of B cell development

Immunol Lett. 2006 Sep 15;107(1):63-70. doi: 10.1016/j.imlet.2006.07.007. Epub 2006 Aug 23.

Abstract

The HSS3/4 enhancer of Crlz1-IgJ locus was first characterized with regard to the activity of HSS1 IgJ promoter in the plasma cells, where both of HSS3/4 enhancer and HSS1 IgJ promoter were found to be opened simultaneously to drive the IgJ gene expression. Unexpectedly, the HSS3/4 enhancer was also found to be opened in the pre-B cells. However, this opening of HSS3/4 enhancer in the pre-B cells could not be related to the IgJ gene expression, because neither the IgJ promoter was opened nor its gene was expressed at the pre-B cell stage of B cell development. Instead, it was postulated that the opened HSS3/4 enhancer might act on some other nearby promoter in pre-B cells, which is now guessed to be the Crlz1 promoter located at 22.5 kb from it. In consistence with this pre-B cell-specific opening of the HSS3/4 enhancer, a pre-B cell-specific in vivo footprint on a sequence similar to the EBF-binding consensus was detected within the enhancer. In this paper, we show that the protein causing the pre-B cell-specific in vivo footprint on a sequence similar to the EBF-binding consensus is truly EBF as judged by EMSA using various oligo-DNA competitors and anti-EBF antibodies. Also, as expected from other previous reports, EBF was shown to be expressed highly in pre-B cells, but very little or not in immature B, mature B and plasma cells using both the cell lines and FACS-sorted normal primary cells. Convincingly, mutations within the EBF site of HSS3/4 enhancer were shown to significantly impair the HSS3/4 enhancer activity in the pre-B cells, but not in the plasma cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • B-Lymphocytes / cytology*
  • Base Sequence
  • Blotting, Western
  • Cell Differentiation / physiology*
  • Cell Line
  • DNA-Binding Proteins / genetics*
  • DNA-Binding Proteins / metabolism
  • Electrophoretic Mobility Shift Assay
  • Enhancer Elements, Genetic / genetics*
  • Flow Cytometry
  • Immunoglobulin J-Chains / genetics
  • Immunoglobulin J-Chains / immunology
  • Mice
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics*
  • Promoter Regions, Genetic / genetics*
  • Trans-Activators / genetics*
  • Trans-Activators / metabolism
  • Transcription Factors / genetics*

Substances

  • Crlz1 protein, mouse
  • DNA-Binding Proteins
  • Ebf1 protein, mouse
  • Immunoglobulin J-Chains
  • Nerve Tissue Proteins
  • Trans-Activators
  • Transcription Factors