Related Experiment Video
Updated: Jul 5, 2026

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence
Published on: December 30, 2025
Brn-3a/POU4F1 interacts with and differentially affects p73-mediated transcription
C D Hudson1, A E Sayan, G Melino
1Medical Molecular Biology Unit, Institute of Child Health, University College London, London, UK.
Abstract:
The Brn-3a/POU4F1 POU transcription factor is critical for the survival and differentiation of specific sensory neurons during development or upon injury; by regulating expression of target genes, either directly or indirectly upon interaction with other proteins. In this study, we demonstrated the physical interaction of Brn-3a with different p73 isoforms and showed co-localization in sensory neurons arising from the neural crest. The biological effects of p73/ Brn-3a interaction depend on the particular p73 isoform, because co-expression of Brn-3a with TAp73 enhanced cell cycle arrest, whereas Brn-3a and DeltaNp73 cooperated to increase protection from apoptosis. Brn-3a antagonized TAp73 transactivation of pro-apoptotic Bax, but co-operated to increase transcription of the cell cycle regulator p21 CIP1/Waf1. The region 425-494 amino acids within the TAp73 C terminus were critical for Brn-3a to repress Bax transactivation, but not for cooperation on the p21 CIP1/Waf1 promoter. Our results suggest that co-factors binding to the p73 C terminus facilitate maximal activation on the Bax but not p21 CIP1/Waf1 promoter and that Brn-3a modulates this interaction. Thus, the physical interaction of Brn-3a with specific p73 isoforms will be critical for determining cell fate during neuronal development or in injured neurons expressing both factors.
Related Concept Videos
Abnormal Proliferation
Negative Regulator Molecules
Interactions Between Signaling Pathways
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
RNA Polymerase II Accessory Proteins
Chromatin Structure Regulates pre-mRNA Processing
The chromatin structure, especially...
Master Transcription Regulators

