FcR γ-chain is associated with GPIb.

After stimulation with 6 μg/mL botrocetin plus 10 μg/mL vWF for the indicated time periods, human platelets were solubilized with an equal volume of lysis buffer containing 2% Brij 35 (vol/vol) or 2% Triton X-100 (vol/vol). GPIb was immunoprecipitated with WGA3, an anti-GPIb MoAb. Precipitated proteins were separated by SDS-PAGE and were analyzed by anti-FcR γ-chain, anti-integrin β1, and anti-GPIb immunoblotting, respectively. The data are representative of 4 experiments. The numbers below the panels show time in seconds.