Fig. 3. Ca²⁺-dependency of GFP-AnxII and GFP-p11 binding to Triton X-100-insoluble cell components. U1242 cells expressing GFP-AnxII or GFP-p11 were extracted with Triton X-100 in the presence of various [Ca²⁺] as described in Materials and Methods. The soluble and insoluble fractions were subjected to western blot analysis using antibodies against GFP or AnxII. The Ca²⁺-dependency of endogenous AnxII binding to the insoluble fraction was the same in both cell populations.