Figure 1.
Generation of SAP102-targeted mice. a, SAP102 has multiple protein–protein interaction domains, including three tandem PDZ (PSD-95/Discs large/zona occludens-1), an Src homology 3 (SH3), and a guanylate kinase (GK) domain (top). We replaced SAP102 exons 2–8 with a selection cassette in targeted mice, deleting the majority of the PDZ-coding sequence and creating a frame-shift mutation between exons 1 and 9 (middle and bottom). The 5′ probe outside the targeting region and primers P1–P3, used for Southern blot and PCR genotyping respectively, are shown. D, DraI restriction sites. b, Southern blots of DraI-digested genomic DNA from wt (+/Y) and targeted (−/Y) ES cells, and wt, heterozygous (+/−), and hemizygous (−/Y) mice confirm the structure of the mutant allele. c, PCR genotyping of targeted SAP102 mice using a common forward primer (P1) and separate reverse primers, P2 and P3, to amplify the wt and mutant alleles, respectively. d, SAP102 is undetectable in Western blots of forebrain extract from hemizygous mutant mice. e, Immunohistochemical staining shows loss of SAP102 throughout the brain of mutant mice. Expression patterns of other NMDA receptor-associated MAGUKs, PSD-95 and PSD-93, are unaffected. Immunohistochemical staining is brown, and hematoxylin counterstain is blue. Scale bars, 2 mm.