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Understanding the function-structure and function-mutation relationships of p53 tumor suppressor protein by
Shunsuke Kato1, Shuang-Yin Han, Wen Liu
1Department of Clinical Oncology, Institute of Development, Aging, and Cancer, Tohoku University, Sendai 980-8575, Japan.
Abstract:
Inactivation of the tumor suppressor p53 by missense mutations is the most frequent genetic alteration in human cancers. The common missense mutations in the TP53 gene disrupt the ability of p53 to bind to DNA and consequently to transactivate downstream genes. However, it is still not fully understood how a large number of the remaining mutations affect p53 structure and function. Here, we used a comprehensive site-directed mutagenesis technique and a yeast-based functional assay to construct, express, and evaluate 2,314 p53 mutants representing all possible amino acid substitutions caused by a point mutation throughout the protein (5.9 substitutions per residue), and correlated p53 function with structure- and tumor-derived mutations. This high-resolution mutation analysis allows evaluation of previous predictions and hypotheses through interrelation of function, structure and mutation.
Insights
Missense mutations in the tumor suppressor p53 (encoded by the TP53 gene) are common in cancers. This study comprehensively analyzes how these TP53 mutations impact p53 protein structure and function.
Area of Science:
- Molecular Biology
- Cancer Genetics
- Protein Biochemistry
Background:
- Missense mutations in the tumor suppressor p53 (encoded by the TP53 gene) are the most frequent genetic alterations in human cancers.
- These mutations often impair p53's DNA-binding and gene transactivation capabilities, crucial for its tumor-suppressive role.
- The functional consequences of many p53 mutations remain poorly understood, hindering therapeutic strategies.
Purpose of the Study:
- To systematically investigate the impact of all possible missense mutations on p53 protein structure and function.
- To correlate mutation sites with observed functional changes and known cancer-derived mutations.
- To provide a high-resolution map of p53 mutational effects for future research and drug development.
Main Methods:
- Utilized comprehensive site-directed mutagenesis to generate 2,314 distinct p53 mutants.
- Employed a yeast-based functional assay to assess the DNA-binding and transactivation activity of each mutant.
- Analyzed mutation data in relation to p53 protein structure and known tumor-derived mutation profiles.
Main Results:
- Generated a comprehensive dataset detailing the functional impact of nearly all possible p53 missense mutations.
- Identified specific amino acid substitutions that significantly alter p53 structure and abolish its tumor-suppressive functions.
- Correlated structural and functional data with mutations found in human cancers, revealing patterns of inactivation.
Conclusions:
- This high-resolution analysis provides unprecedented insight into the structure-function relationships of the p53 tumor suppressor.
- The findings clarify the effects of numerous p53 mutations previously not well-characterized.
- This resource facilitates a deeper understanding of cancer development and aids in the evaluation of p53-targeted therapies.