Immunocytochemistry was performed as described previously (ZhuGe et al., 2006). Polyclonal rabbit antibodies for RYRs were generated using the epitopes RREGPRGPHLVGPSRC for RYR1 (Mitchell et al., 2003) and KAALDFSDAREKKKPKKDSSLSAV for RYR2 (Tunwell et al., 1996). The polyclonal rabbit anti-RYR3 antibody was developed against purified glutathione-S-transferase fusion protein corresponding to the region of low homology between the transmembrane domains 4 and 5 of RYR3 (Giannini et al., 1995). Preimmune serum was used as negative controls of anti-RYRs. BK channel antibody was purchased from BD. The immunogen for this anti-BK channel is residues 995–1,113 of human BKCaα, and the specificity of this antibody has been confirmed in the studies of several cell types and tissues (i.e., Samaranayake et al., 2004; Lim and Park, 2005; Brainard et al., 2005). Mouse preimmune IgG was used as a negative control for the anti-BK channel.
