Related Experiment Video
Updated: Jul 11, 2026
Yeast As a Chassis for Developing Functional Assays to Study Human P53
Published on: August 4, 2019
Analysis of p53-RNA interactions in cultured human cells
Kasandra J-L Riley1, L James Maher
1Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA.
Abstract:
Tumor suppressor p53 is a well-characterized transcription factor that binds DNA. More enigmatic are the RNA-binding properties of p53 and their physiological relevance. We used three sensitive co-immunoprecipitation methods in an attempt to detect RNAs that tightly associate with p53 in cultured human cells. Although recombinant p53 protein binds RNA in a sequence-nonspecific mode, we do not detect specific in vivo RNA binding by p53. These results suggest that RNA binding is prevented by post-translational p53 modifications. A ribonucleoprotein (not p53) is purified by multiple IgG monoclonal antibodies (including anti-p53 antibodies) from both p53 +/+ and p53 null cells. Caution is therefore required in interpreting RNA co-immunoprecipitation experiments. Though not formally excluded, these results do not support models in which p53 binds specific RNA partners in vivo.
Insights
The tumor suppressor p53 protein does not appear to bind specific RNAs in human cells. Post-translational modifications may prevent RNA binding, and co-purified ribonucleoproteins can complicate experimental results.
Area of Science:
- Molecular Biology
- Cell Biology
- Cancer Research
Background:
- The tumor suppressor p53 is a known DNA-binding transcription factor.
- The physiological relevance of p53's potential RNA-binding properties remains unclear.
Purpose of the Study:
- To investigate the in vivo RNA-binding capabilities of the p53 protein.
- To determine if p53 associates with specific RNA molecules in human cells.
Main Methods:
- Utilized three sensitive co-immunoprecipitation methods to detect p53-associated RNAs.
- Examined RNA binding in cultured human cells, including p53 +/+ and p53 null cell lines.
Main Results:
- Recombinant p53 protein demonstrated sequence-nonspecific RNA binding in vitro.
- No specific in vivo RNA binding by p53 was detected.
- A ribonucleoprotein complex, independent of p53, was co-purified by anti-p53 antibodies.
Conclusions:
- Post-translational modifications likely inhibit p53's in vivo RNA binding.
- Caution is advised when interpreting co-immunoprecipitation data involving p53 and RNA.
- Current findings do not support models of direct, specific in vivo RNA binding by p53.
Related Concept Videos
02:23Abnormal Proliferation
02:36DNA Damage Can Stall the Cell Cycle
02:36DNA Damage can Stall the Cell Cycle
01:23Negative Regulator Molecules
01:53RNA Stability