FIGURE 3.

CIN85 positively regulates the degradation of FcγRIIa. Bt₂cAMP-differentiated PLB-985 cells were transfected with a negative control siRNA or a siRNA against CIN85 as described under “Experimental Procedures.” Forty-eight h post-transfection, FcγRIIa was cross-linked for the indicated times. A, whole cell lysates were immunoblotted using antibodies recognizing FcγRIIa (CT10 antibody), CIN85, or c-Cbl (loading control). The line graph represents the compilation of densitometric ratios derived from three independent experiments. B, the same samples were probed for tyrosine phosphorylation residues (α-pY). These results are representative of three independent experiments. C, transfected cells were incubated with fluorescent IgG-opsonized zymosan as described under “Experimental Procedures.” Fluorescence was measured by flow cytometry. The phagocytic index was calculated by multiplying the number of phagocytic cells by the number of internalized zymosan particles/cell (mean fluorescence intensity). This graph is a quantification of the means of four independent experiments. WB, Western blot. Error bars, S.E.