Effects of substitutions of 674C and 687C of GPIIb in the surface exposure and BiP association of GPIIb-IIIa complexes.

CHO-IIIa cells were transfected with the cDNA encoding normal [674C]GPIIb or mutant forms of GPIIb, as indicated. In the upper panel, the surface expression of GPIIb-IIIa complex was determined by flow cytometry, using an anti-GPIIb moAb. The results are expressed as a percentage of the surface exposure of normal [674C]GPIIb-IIIa complexes. The results are the means ± SEM of at least 3 independent experiments in duplicate. In the lower panel, immunoprecipitation of the cell lysates and Western blot analysis of the precipitates were performed as described in “Materials and methods.”