FIGURE 2.

rBSG1 is required MCT1 and MCT4 in rod photoreceptor cells. A, qPCR showing reduced levels of Bsg1 in RodΔBsg retina without compensatory increases in levels of other Ig superfamily members. Bars indicate average ± SEM for N = 4 mice. B, Immunofluorescence of BSG (red) and MCT1 (green) of frozen sections of eyes from control and RodΔBsg mice. Loss of BSG1 resulted in loss of MCT1 in inner segments. MCT1 was still detected in rods (arrows) but was not trafficked to the plasma membrane (Scale bar = 25 µm). Asterisks indicate cones which retain both BSG1 and MCT1. Data are representative of N = 3 experiments. C, Western blots of detergent soluble lysates from RodΔBsg retinas confirms genetic deletion of Bsg from rod photoreceptors targets MCTs for degradation. Blots are representative of N = 8 mice. D, Western blot quantification of MCT1 and MCT4 compared to β-tubulin of control and RodΔBsg samples. E, Comparison of Log₂(CPM) values of Slc16a1 (MCT1) and Slc16a3 (MCT4) between rods and cones at P28 from GSE74660. F, Immunoprecipitation of MCT1 and MCT4 shows enrichment of rBSG1 in control as compared to RodΔBsg retina. Data are representative of N = 3 experiments