Transactivation and reactivation capabilities of temperature-dependent p53 mutants in yeast and human cells

Abstract

The p53 protein is a sequence-specific transcription factor controlling the expression of multiple genes and protecting cells from oncogenic transformation. In many tumors, the p53 protein is completely or partially inactivated by mutations in the p53 gene. We analyzed the transactivating activity of nine human temperature-dependent (td) p53 mutants in yeast cells. Mutations in seven of them were localized in the β-sandwich-coding region of the p53 gene, eight p53 mutants were temperature-sensitive and the R283C mutant was cold-sensitive. Patterns of their transactivation abilities towards three different responsive elements, the extent of their temperature dependency as well as discriminativity, were considerably variable. Similarly, their capacity to become reactivated by amifostine varied from complete resistance to high sensitivity. Transactivation abilities and temperature dependency of six p53 td mutants were determined in transiently-transfected H1299 human cells and revealed substantial concordance between the activity patterns of the p53 mutants in yeast and human cells. We concluded that the td p53 mutants do not comprise a uniform group, therefore, the behavior of each mutant has to be tested individually.

p53 regulates epithelial–mesenchymal transition induced by transforming growth factor β

“…2A). The location of this point mutation has been previously characterized in human p53 as being in a hot‐spot region of the DNA‐binding domain of the TP53 gene where mutations affect the transcriptional activity of p53 (Thukral et al, 1994; Jagosova et al, 2012). In order to estimate the abundance of expression of each p53 allele in the NMuMG cells, we measured the frequency of wild type and point‐mutant p53 cDNAs that were recovered in our cloning experiments.…”

Therapy-induced mutations drive the genomic landscape of relapsed acute lymphoblastic leukemia

“…This finding indicates that although R367Q is likely treatment induced, most other NT5C2 mutations are caused by other mutational processes. In addition, novel signature B likely caused three NR3C1 mutations (51.0%-78.0% probability) that confer glucocorticoid resistance (Figure 2A) and five loss-of-function [68][69][70][71][72] TP53 mutations (72.4%-98.5% probability) (Figure 5D). The TP53 R196G variant, which causes chemotherapy resistance (Figure 2D), was found at the C[C.G]G novel signature B-preferred context (supplemental Figure 15B) and had a 98.5% probability of induction by the signature.…”

TP53 Mutants in the Tower of Babel of Cancer Progression

“…TS reflects the thermodynamic impact of introduced single amino-acid changes and it is a common feature of many TP53 mutant proteins [Jagosova et al, 2012] (Fig. 1).…”