This knock-out allele of Pam (peptidylglycine alpha-amidating monooxygenase) deletes exons 2 and 3, resulting in embryonic lethality between E14.5 and E15.5 due to severe edema. Heterozygous (PAM het) mice exhibit altered copper homeostasis, anxiety-like behavior,and a high sensitivity to seizures.
John Pintar, Robert Wood Johns Medical School
Pam (peptidylglycine alpha-amidating monooxygenase) is a cuproenzyme involved in the posttranslational processing of peptide hormones including many neuropeptides. This targeted mutation deletes exons 2 and 3, resulting in embryonic lethality between E14.5 and E15.5 due to severe edema, decreased thickness of the epithelial cells of the bronchi, and thinning of the aorta and carotid arteries. Heterozygous (PAM het) mice exhibit altered copper homeostasis, deficits in peripheral vasoconstriction, cold sensitivity, anxiety-like behavior, impaired short and long term contextual and cued fear conditioning, deficiencies in long-term potentiation in the amygdala and a high sensitivity to seizures. Supplemental copper ameliorated some but not all of the phenotypes. Aged (10 months or more) heterozygous mice develop mild glucose intolerance and increased adiposity. This strain may be useful for studying the involvement of amidated neuropeptides in multiple systems including anxiety-spectrum disorders, copper deficiency, cardiovascular regulatory functions.
A targeting vector containing a neomycin cassette was used to disrupt exons 2 and 3, which encode the start site, signal sequence and part of the first copper binding site. The construct was electroporated into 129S7/SvEvBrd-Hprt1b-m2 derived AB2.2 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts. The resulting male chimeric animals were crossed to C57BL/6J female mice and offspring were backcrossed to C57BL/6J for 50 generations.
|Allele Name||targeted mutation 1, John E Pintar|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Pam, peptidylglycine alpha-amidating monooxygenase|
|Strain of Origin||129S7/SvEvBrd-Hprtb-m2|
|Molecular Note||Exons 2 and 3, encompassing the translational start site and residues required for catalytic activity of the protein, were replaced with a neomycin resistance gene.|
While maintaining a live colony, these mice are bred as heterozygote matings. Mice homozygous for the mutation are not viable.
When using the PAMhet mouse strain in a publication, please cite the originating article(s) and include MMRRC stock #43561 in your Materials and Methods section.