Figure 7
The SRCR domain of SR-AIKA mediates the oAβ binding. Lysine residues at 332, 335, and 338 in the collagenous domains of SR-AI and 341 were mutated to alanine. COS-7 cells were transfected with SR-AI, SR-AIKA, or 341KA. A and B, Western blot analysis of total cell lysates and avidin pull-down of biotinylated lysates after PNGase F cleavage. C, Relative levels of surface-biotinylated SR-AI variants were quantified. D, Western blot analysis of total cell lysates after PNGase F or Endo H cleavage. E, Representative merged confocal images of surface-bound oAβ on the plasma membrane of transfected cells. Scale bar, 20 μm. The experiments were repeated at least three times. F and G, Relative fluorescence intensities of internalized oAβ and AcLDL were quantified in more than 100 SR-A-positive cells using MetaMorph software. Bars indicate mean ± SEM of at least three independent experiments. Experimental groups labeled with different letters were significantly different from each other (p < 0.05).