FIGURE 7.

Antibodies to sea urchin TPC1and TPC3 specifically immunoprecipitate proteins photoaffinity-labeled with [³²P-5N₃]NAADP. The first four lanes (left to right) are immunoprecipitated fractions from experiments using control antibody-, anti-TPC1-, anti-TPC2-, and anti-TPC3-coupled agarose beads, respectively. The far right lane (Input lane) is the input extract used for the immunoprecipitation experiments and represents CHAPS solubilized egg extract photolabeled in the absence 5 μm NAADP. The lane labeled Input + 1μm NAADP represents CHAPS-solubilized egg extract photolabeled in the absence of 5 μm NAADP. A phosphor image of the gel is shown.