Figure 6.

Clustered type II InsP₃ receptors align with ER tubules in activated RBL-2H3 cells. Cells were grown on coverslips, primed with DNP-specific IgE, and incubated for 10 min at 37°C with 1 μg/ml DNP-BSA (A and B) or 1 μM ionomycin (C). Cells were fixed and doubled labeled with CT2 polyclonal antibodies and Cy3-conjugated secondary antibodies together with anti-BiP monoclonal antibody and FITC-conjugated secondary antibodies. Arrowheads point to examples of receptor clusters on ER tubules that extend into the cell periphery.