Chunk #24 — Results — The Mr of G118/D40-hMOPR was lower than that of A118/N40-hMOPR, due to different N-glycosylation, when both were stably expressed in cultured cells
N-linked glycosylation in 7TMRs has been shown to play important role in proper folding and trafficking of the receptor proteins [for example, [23]]. We thus investigated if the SNP affects stability and trafficking of the MOPR. Since it is not feasible to carry out such studies in brain tissues, we used cells in culture. Cell lines (CHO cells and HEK293 cells) stably expressing 3HA-tagged A118/N40-hMOPR and G118/D40-hMOPR were established. Immunoblotting of CHO cell membranes with anti-HA revealed that both A118/N40-hMOPR and G118/D40-hMOPR migrated as broad and diffuse bands and the G118/D40-hMOPR exhibited a lower median Mr (76 kDa) (Fig. 4, lane 3) than A118/N40-hMOPR (81 kDa) (Fig. 4, lane 2). Similarly, in HEK293 cells both MOPR variants migrated as diffuse bands and G118/D40-hMOPR had a lower median Mr (80 kDa) (Fig. 4, lane 5) than A118/N40-hMOPR (85 kDa) (Fig. 4, lane 4).
