Figure 6.

Homer was less tyrosine phosphorylated in Fmr1 KO than control mice, whereas NR2A, mGlu5, and GluR1 were equally phosphorylated in both wt and Fmr1 KO mice. A, Western blots of proteins immunoprecipitated with anti-phosphotyrosine antibody from 30 μg of forebrain SPMs of P21 control (wt) and Fmr1 KO mice. Lanes were loaded with total SPM proteins (Tot) or with immunoprecipitated proteins (P). Anti-NR2A, anti-mGlu5, anti-GluR1, and anti-Homer antibodies were used for immunodetection. A control experiment performed in the absence of phosphatase inhibitor (Ph inhib) shows a strong reduction in tyrosine phosphorylation levels of Homer and mGlu5 proteins. B, Quantification of GluR1, mGlu5, and Homer compared with NR2A levels in the immunoprecipitated fraction of wt (gray columns) and Fmr1 KO (black columns) mice. Data are mean of four to nine experiments (n = 4 for GluR1; n = 8 for mGlu5; n = 9 for Homer; *p < 0.05, Student's t test).