Related Experiment Video

Updated: Aug 8, 2026

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization
13:55

Combined Immunofluorescence and DNA FISH on 3D-preserved Interphase Nuclei to Study Changes in 3D Nuclear Organization

Published on: February 3, 2013

Qualitative changes in the subunit composition of kappa B-binding complexes during murine B-cell differentiation

S Miyamoto1, M J Schmitt, I M Verma

  • 1Molecular Biology and Virology Laboratory, Salk Institute, San Diego, CA 92186-5800.

Proceedings of the National Academy of Sciences of the United States of America
|May 24, 1994
PubMed

Insights

During B cell differentiation, the transcription factor NF-κB changes its composition from p50-p65 to p50-Rel. This shift enhances binding to the immunoglobulin kappa light chain gene, activating its expression.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • Nuclear factor kappa B (NF-κB) transcription factors regulate immune responses and cell differentiation.
  • The composition of NF-κB complexes, specifically kappa B-binding complexes, varies between immune cell types and differentiation stages.
  • Understanding these variations is crucial for deciphering gene regulation in B cell development.

Purpose of the Study:

  • To investigate the subunit composition of kappa B-binding complexes in murine B cell differentiation.
  • To determine the role of specific NF-κB heterodimers in the transcriptional activation of the immunoglobulin kappa light chain gene.

Main Methods:

  • Electrophoretic mobility shift assays (EMSA) to analyze kappa B-binding complexes.
  • Treatment of pre-B cell lines with lipopolysaccharide (LPS) to induce differentiation.
  • Analysis of Rel and p65 protein expression levels.
  • Assessment of binding affinity of different NF-κB heterodimers to the immunoglobulin kappa enhancer.

Main Results:

  • Murine mature B cells predominantly contain p50-Rel kappa B-binding complexes.
  • Murine pre-B cells primarily exhibit p50-p65 heterodimers, which shift to p50-Rel upon LPS treatment.
  • This shift is preceded by increased Rel expression and correlates with immunoglobulin kappa light chain gene expression.
  • The p50-Rel complex demonstrates a significantly higher binding stability (at least 20-fold) to the kappa B enhancer site compared to the p50-p65 dimer.

Conclusions:

  • Rel expression augmentation during B cell differentiation drives a subunit exchange in kappa B-binding complexes.
  • The formation of the p50-Rel heterodimer is critical for the stable binding and transcriptional activation of the immunoglobulin kappa light chain gene.
  • This mechanism provides insight into the regulation of immunoglobulin gene expression during B cell maturation.

More Related Videos

Methods for the Modulation and Analysis of NF-κB-dependent Adult Neurogenesis14:58

Methods for the Modulation and Analysis of NF-κB-dependent Adult Neurogenesis

Published on: February 14, 2014

Flow Cytometric Characterization of Murine B Cell Development08:25

Flow Cytometric Characterization of Murine B Cell Development

Published on: January 22, 2021

Related Concept Videos

Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein.
Protein Complexes with Interchangeable Parts01:57

Protein Complexes with Interchangeable Parts

Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Co-activators and Co-repressors02:04

Co-activators and Co-repressors

Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...