These Gria1/GluR1 "penta" mutant mice carry five alanine substitutions (S831A, T838A, S839A, T840A, and S845A) that enable studies of phosphorylation as they pertain to synaptic transmission and plasticity.
Richard L Huganir, Johns Hopkins University School of Medicine
Phosphorylation of various AMPA receptor subunits, including Gria1 (GluR1), can alter synaptic transmission and plasticity at excitatory glutamatergic synapses in the central nervous system.
These GluR1 "penta" phosphomutant mice express five alanine substitutions (S831A, T838A, S839A, T840A, and S845A) that were introduced to the mouse Gria1 (glutamate receptor, ionotropic, AMPA1 (alpha 1)) gene, thus blocking T840 phosphorylation and preventing phosphorylation from other upstream sites. Western blots indicate that GRIA1 protein is still expressed in homozygotes. Hippocampal cytoarchitecture is normal as shown by Nissl stain, and protein distribution is normal as shown by immunohistochemistry. Long-term potentiation (LTP) induced by theta burst stimulation (TBS) is reduced in adult homozygotes, and although long-term depression (LTD) induced by a paired-pulse 1 Hz protocol is absent in adult animals, it is present in young animals. Mutant mice do not show any gross abnormalities in anatomy and behavior.
A neomycin resistance cassette flanked by loxP sites was inserted to the intron upstream of the last coding exon. Five alanine substitutions (S831A, T838A, S839A, T840A, and S845A) were introduced to phosphorylation sites by directed PCR. The mutations were introduced through homologous recombination in (129X1/SvJ x 129S1/Sv)F1- Kitl+-derived R1 embryonic stem (ES) cells. After germline transmission was confirmed, the neomycin cassette was excised through crosses with a CMV-Cre strain on a mixed C57BL/6-129 genetic background. This strain was backcrossed to C57BL/6 for 12 generations by the donating lab.
|Allele Name||targeted mutation 4, Richard Huganir|
|Gene Symbol and Name||Gria1, glutamate receptor, ionotropic, AMPA1 (alpha 1)|
|Strain of Origin||(129X1/SvJ x 129S1/Sv)F1-Kitl+|
|Molecular Note||Serines 831, 839, 845 and threonines 838 and 840 were mutated to alanine by PCR mutagenesis prior to homologous recombination. A floxed neo cassette was inserted upstream of the last conding exon was removed by cre-mediated recombination following a cross to mice containing Tg(CMV-cre)1Nagy. Western blot analysis with was performed to confirm the presence of the protein but loss of the phosphorylation sites.|
Homozygotes and heterozygotes are viable and fertile.
When using the B6.129(Cg)-Gria1tm4Rlh/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #024420 in your Materials and Methods section.