In these p53LSL-53,54 mice, which carry a mutation in the 2nd transcriptional activation domain, expression of the mutant TRP53 protein is silenced until Cre recombinase mediates excision of the floxed STOP cassette. These mice may be useful in studies of p53 function and the role of p53 as a transcriptional activator in tumor suppression.
Laura Attardi, Stanford University Medical Center
The Trp53, transformation related protein 53, gene encodes a tumor suppressor protein, which functions as a transcription factor regulating expression of more than 100 target genes. Mutations resulting in inactivation of p53 protein facilitates tumor progression. These p53LSL-53,54 mice carry F53Q;F54S point mutations in exon 4, in the 2nd transcriptional activation domain, and a floxed STOP cassette upstream of exon 2. Expression of the mutant TRP53 protein is silenced until Cre recombinase mediates excision of the floxed STOP cassette. After Cre recombinase mediated removal of the floxed STOP cassette cells from the resulting mice exhibit no compromise in transactivation of p53 targets relative to wildtype p53. When bred to Cre recombinase expressing mice, these mice could be used to generate tumor cells for engraftment experiments. Mice that are homozygous for the targeted mutation are viable, but have decreased fertility.
A targeting vector designed by Dr. Laura D. Attardi (Stanford University School of Medicine) containing a floxed STOP element with 4 poly adenylation sites, and a puromycin resistance cassette, was utilized to insert the floxed STOP cassette upstream of exon 2 and the F53Q;F54S point mutation into exon 4. The construct was electroporated into 129S4/SvJae derived J1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to 129 Sv/J mice.
Upon arrival at The Jackson Laboratory, the mice were crossed to 129S1/SvImJ (Stock No. 002448) at least once to establish the colony.
|Allele Name||targeted mutation 3, Laura D Attardi|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Trp53, transformation related protein 53|
|Strain of Origin||129S4/SvJae|
|Molecular Note||A floxed puromycin/transcription stop cassette was inserted upstream of exon 2. In addition,mutations were inserted in exon 4 altering codon 53 from phenylalanine to glutamine and codon 54 from phenylalanine to serine. The second transactivation domain is incapacitated once the stop sequences are removed by cre expression.|
When maintaining a live colony, these mice can be bred as heterozygotes. Homozygotes exhibit decreased fertility.
When using the p53LSL-53,54 mouse strain in a publication, please cite the originating article(s) and include JAX stock #018431 in your Materials and Methods section.