Portions of the CH1 domain were deleted from the Ep300 gene to create these hypomorphic p300 deltaCH1 mice that are useful in studies of hypoxia-responsive transcription.
Paul K. Brindle, St. Jude Children's Research Hospital
Ep300 (E1A binding protein p300) is a histone acetylase that is required for normal development. It interacts with a significant percentage of mammalian transcriptional regulatory proteins and has a CH1 domain that binds the C-terminal activation domain (C-TAD) of the hypoxia-inducible transcription factors HIF-1α and HIF-2α. This interaction is highly essential for hypoxia-responsive transcription, and is relevant to processes of glucose metabolism, angiogenesis, hematopoiesis, cell survival, invasion, and vascular tone.
These mice carry a targeted, partial, in-frame deletion of the CH1 domain in the mouse Ep300 gene (amino acids 329-379) that results in a hypomorphic protein. Western blots indicate that normal levels of a stable protein with intact HAT domain are produced. This strain was backcrossed to 129S2/SvPasCrl for 22 generations by the donating lab.
Homozygotes on a random mixed background incorporating C57BL/6 and 129 alleles are overtly normal, although they are produced at about 50% the expected frequency. Two separate lines, one backcrossed to C57BL/6J (see Stock No. 025169), the other backcrossed to 129S2/SvEvTac (this strain) were generated by the donating laboratory. Homozygous mutants generated from an F1 cross of these two backgrounds are viable and have increased metabolic control. They are lean and demonstrate increased insulin sensitivity.
Homozygous p300 deltaCH1 mice on this 129-backcrossed genetic background are produced at reduced Mendelian ratios (1 in 10 rather than the anticipated 1 in 4). Insulin sensitivity has not been tested and body size is normal.
Portions of the CH1 domain (amino acids 329-379) was deleted and a neomycin resistance cassette flanked by FRT sites was introduced to the downstream intron through homologous recombination in TL1 129S6/SvEv-derived embryonic stem (ES) cells. Transient infection of the ES cells with a Flp-expressing vector excised the neomycin cassette. Resultant chimeric mice were crossed with C57BL/6J animals, then to 129P2/Ola for 3 generations. Fertility/productivity issues precipitated 22 generations of backcrossing to 129S2/SvPasCrl by the donating laboratory.
|Allele Name||targeted mutation 3, Paul K Brindle|
|Gene Symbol and Name||Ep300, E1A binding protein p300|
|Strain of Origin||129S6/SvEvTac|
|Molecular Note||Portions of the CH1 domain (amino acids 329-379) encoded by exon 4 were deleted and a neomycin resistance cassette flanked by FRT sites was introduced to the downstream intron. Transient infection of the ES cells with a Flp-expressing vector excised the neomycin cassette. RT-PCR confirmed the deletion in mutant MEFs.|
Heterozygotes are viable and fertile. Homozygotes are produced at reduced Mendelian ratios (1 in 10 rather than the anticipated 1 in 4).
When using the p300 delta CH1 mouse strain in a publication, please cite the originating article(s) and include JAX stock #025527 in your Materials and Methods section.