Related Experiment Video

Updated: Oct 13, 2026

An Optimized Protocol for Electrophoretic Mobility Shift Assay Using Infrared Fluorescent Dye-labeled Oligonucleotides
09:58

An Optimized Protocol for Electrophoretic Mobility Shift Assay Using Infrared Fluorescent Dye-labeled Oligonucleotides

Published on: November 29, 2016

DNA binding and transactivating properties of the paired and homeobox protein Pax4

A Kalousová1, V Benes, J Paces

  • 1Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic. Anna@biomed.cas.cz

Biochemical and Biophysical Research Communications
|June 12, 1999
PubMed

Insights

Transcription factors Pax-4 and Pax-6 regulate pancreatic development. Gene targeting shows they are not interchangeable, with Pax-4 potentially acting as a Pax-6 repressor due to binding competition and lower activity.

Area of Science:

  • Developmental Biology
  • Molecular Genetics

Background:

  • Transcription factors Pax-4 (Paired box 4) and Pax-6 (Paired box 6) are crucial for pancreatic cell differentiation.
  • Understanding their specific roles and interactions is key to comprehending pancreatic development.

Purpose of the Study:

  • To clone and characterize the mouse Pax-4 gene.
  • To investigate the functional relationship and DNA-binding specificities of Pax-4 and Pax-6.
  • To determine the transactivation potential of Pax-4 compared to Pax-6.

Main Methods:

  • Gene cloning and sequencing of the mouse Pax-4 gene.
  • Gene-targeting experiments to assess functional redundancy.
  • Electrophoretic mobility shift assays (EMSAs) to identify DNA-binding specificities.
  • Reporter gene assays to measure transactivation potential.

Main Results:

  • The mouse Pax-4 gene comprises 10 exons over a 4.7-kbp region.
  • Pax-4 and Pax-6 are not functionally redundant in tissues where both are expressed.
  • Identified DNA-binding specificities for Pax-4 paired domain and homeodomain, noting similarities with Pax-6 despite amino acid differences.
  • Pax-4 homeodomain preferentially dimerizes on specific inverted TAAT motifs.
  • Pax-4's transactivation domain exhibits lower activity than Pax-6's.

Conclusions:

  • Pax-4 and Pax-6 have distinct, non-interchangeable roles in pancreatic development.
  • Pax-4's lower transactivation potential and competitive binding suggest it may act as a repressor of Pax-6 activity.
  • These findings provide insights into the regulatory mechanisms governing pancreatic cell differentiation.

More Related Videos

HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries10:10

HOX Loci Focused CRISPR/sgRNA Library Screening Identifying Critical CTCF Boundaries

Published on: March 31, 2019

The Mammalian Ocular Lens in Focus: Development, Anatomy, Physiology, Transparency, Biomechanics, and Age-Related Challenges05:08

The Mammalian Ocular Lens in Focus: Development, Anatomy, Physiology, Transparency, Biomechanics, and Age-Related Challenges

Published on: May 29, 2026

Related Concept Videos

Cooperative Binding of Transcription Regulators02:13

Cooperative Binding of Transcription Regulators

Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome.  Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
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...
Eukaryotic Transcription Activators02:42

Eukaryotic Transcription Activators

Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Master Transcription Regulators02:23

Master Transcription Regulators

Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a  complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
Cooperative Binding of Transcription Regulators02:13

Cooperative Binding of Transcription Regulators

Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome.  Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
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...