p53 mutants without a functional tetramerisation domain are not oncogenic.

Abstract

p53 is altered in about 50 % of cancers. Most of the p53 mutants have lost the wild-type tumour suppressor activity but show oncogenic properties. The majority of the p53 alterations are missense mutations of residues located in its DNA binding domain (DBD). Only a few mutations concern residues in its tetramerisation domain (TD). However, the study of mutant proteins identified in tumors that do not form tetramers has shown that they have lost the wild-type activity like most of the p53 DBD mutants. Here, we show that two of such mutant proteins, Arg342Pro and Leu344Pro are not dominant negative and do not stimulate the expression of a reporter gene under the control of the multi-drug resistance gene-1 (MDR-1). This suggests that to be oncogenic, p53 mutants need to form tetramers. Accordingly, the dominant negative effect and the ability of a tetrameric mutant protein, Asp281Gly, to stimulate the MDR-1 promoter are abolished when its TD is rendered non-functional by the mutation of leucine 344 to a proline residue. These results suggest that mutations in the TD, are less selected in tumors than mutations in the DBD because they do not lead to oncogenic proteins.

• Authors: P Chène, E Bechter
• Journal: Journal of molecular biology (J Mol Biol) Vol. 286 Issue 5 Pg. 1269-74 (Mar 12 1999) ISSN: 0022-2836 [Print] Netherlands
• PMID: 10064694 (Publication Type: Journal Article)
• Copyright: Copyright 1999 Academic Press.

Chemical References

• ATP Binding Cassette Transporter, Subfamily B, Member 1
• Oligodeoxyribonucleotides
• Recombinant Proteins
• Tumor Suppressor Protein p53

Topics

• ATP Binding Cassette Transporter, Subfamily B, Member 1 (genetics)
• Amino Acid Substitution
• Genes, Dominant (genetics)
• Genes, p53
• Humans
• Mutation
• Neoplasms (etiology, genetics)
• Oligodeoxyribonucleotides (genetics, metabolism)
• Osteosarcoma
• Phenotype
• Precipitin Tests
• Promoter Regions, Genetic (genetics)
• Protein Binding
• Protein Biosynthesis
• Recombinant Proteins (biosynthesis, genetics, metabolism)
• Response Elements (genetics)
• Transfection
• Tumor Cells, Cultured
• Tumor Suppressor Protein p53 (antagonists & inhibitors, chemistry, genetics, metabolism)