The Tumor Suppressor Protein p53 and its Physiological Splicing Variant p53 as in a Mouse Mammary Cancer Model.
Abstract
Cellular and molecular aspects of p53 and an alternatively spliced protein, p53as, are being examined during cancer progression in both a mouse mammary and epidermal model. We report here that both p53 and p53as are expressed in cell lines and tissues of the mouse mammary model and, as previously reported, in epidermal cells. The half life of both proteins has been determined in asynchronous cells from both model systems. In mammary cells, but not in epidermal cells, p53as is longer lived than p53. Synchronizing untreated cells, either by serum deprivation or by density arrest followed by serum deprivation, has not proven reproducible enough for the proposed studies of cell cycle dependency of protein stability. Therefore, we will use selected drugs for a dual purpose: (1) to induce p53 levels and (2) to arrest cells at specific cell cycle stages. The p53as DNA binding sequence has been determined and found to be the same as the p53 sequence. However, we have noted sequences which may permit uncovering new p53 transcriptional target genes. We have begun studies of tissue specific p53- or p53as-associated proteins by the construction and isolation of fusion proteins of the glutathione-S-transferase protein and the C-terminus of either p53 or p53as and by purification of p53 and p53as proteins from a baculovirus system.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1996
- Accession Number
- ADA322119
Entities
People
- Molly Kulesz-martin
Organizations
- Health Research, Incorporated