Enhanced binding of a 95 kDa protein to p53 in cells undergoing p53-mediated growth arrest.

Authors

Y Barak
M Oren

Document Type

Article

Publication Date

1992

Keywords

Cell-Division, Cell-Line-Transformed, Clone-Cells, DNA-Binding-Proteins, Electrophoresis-Polyacrylamide-Gel, Genes-p53, Genes-ras, Molecular-Weight, Mutagenesis-Site-Directed, Plasmids, Protein-p53, Rats, SUPPORT-NON-U-S-GOVT, SUPPORT-U-S-GOVT-P-H-S

First Page

2115

Last Page

2121

JAX Source

EMBO J 1992 Jun; 11(6):2115-21.

Grant

RO1CA40099/CA/NCI

Abstract

To explore the biochemical functions of p53, we have initiated a search for cellular p53-binding proteins. Coprecipitation of three polypeptides was observed when cell lines overexpressing a temperature-sensitive (ts) p53 mutant were maintained at 32.5 degrees C (wild-type p53 activity, leading to growth arrest) but not at 37.5 degrees C (mutant p53 activity). One of these three proteins, designated p95 on the basis of its apparent molecular mass, was highly abundant in p53 immune complexes. We demonstrate herein that p95 is a p53-binding protein, which exhibits poor p53-binding in cells overproducing several distinct mutant p53 proteins. Yet, p95 associates equally well with both the wild-type (wt) and the mutant conformations of the ts p53 in transformed cells growth-arrested at 32.5 degrees C. On the basis of our findings we suggest that wt p53 activity increases p53-p95 complex formation and that such interaction may play a central role in p53 mediated tumour suppression.

Recommended Citation

Barak Y, Oren M. Enhanced binding of a 95 kDa protein to p53 in cells undergoing p53-mediated growth arrest. EMBO J 1992 Jun; 11(6):2115-21.