Cellular Proteins Interacting with the Tumor Suppressor Protein p53.
Annual rept. 15 Jul 94-14 Jul 95,
BRIGHAM AND WOMEN'S HOSPITAL BOSTON MA
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The DNA replication factor RPA physically associates with the tumor suppressor protein p53, an interaction that could be important for the function of both these proteins in normal and cancer cells. We have created two mutant forms of p53 with the desired transcriptional activation property. Thus we are now in the position to use these mutant versions of p53 to test whether the RPA binding ability of p53 is important for its multiple functions. Deletion fragments of Rpa1 were made by in vitro transcription translation to determine which parts of Rpa1 bound to p53. Binding to p53 requires a region of Rpa1 overlapping with the high affinity binding site for DNA explaining how p53 could competitively interfere with the DNA binding function of RPA. The evolutionarily conserved putative zinc finger near the C terminus of Rpa1 was not required for binding to p53. We have also extended our study to the p2l protein, which is induced by p53 and interacts with both the cdk2 kinase, and a DNA replication factor, PCNA. Domains of the p2l protein have been defined that execute these functions independently.
- Medicine and Medical Research