Figure 8.

Phosphorylated Homer3 and cytosolic Homer3 were decreased in parallel in P/Q–Ca²⁺-channel knock-out mice. A, CaMKIIα activity in wild (WT), P/Q–Ca²⁺-channel knock-out (P/Q KO), and IP₃R1 knock-out (IP₃R1 KO) mouse at P14 stage was examined by assessing the autophosphorylation level of CaMKIIα (pThr286) in S1 fraction from each mouse cerebellum. B, Denuclear crude lysates (lanes 1, 4, 7), cytosolic (lanes 2, 5, 8), and crude microsome (lanes 3, 6, 9) fractions were prepared from wild-type (lanes 1–3), P/Q knock-out (lanes 4–6), and IP₃R1 knock-out (lanes 7–9) mouse cerebella, according to experimental procedures. Each fraction was examined for content of phosphorylated Homer3 at each site and total Homer3 protein by Western blotting. C, Cryosections were prepared from P14 wild-type and P/Q knock-out mice and examined for distribution of phosphorylated Homer3 at Ser120 (pS120) and total Homer3 by immunohistochemical analysis.