Skip to main content
. 2021 Oct 11;297(5):101299. doi: 10.1016/j.jbc.2021.101299

Figure 8.

Figure 8

Surface biotinylation shows that little if any S1R reaches the cell surface, similar to an ER chaperone.A, S1R−/− HEK293 cells expressing WT S1R or the L214N construct were treated with or without 100 nM Pre-084 for 16 h, followed by cell surface biotinylation with sulfo-NHS-LC-Biotin. Ten precentage of the cell lysates were immunoblotted with anti-S1R (total S1R). The rest of the lysates were precipitated using streptavidin-agarose beads before immunoblotting (cell surface S1R). The lower panel is an overexposure of the blot from the upper panel. B, similar to (A) but with S1R−/− or S1R+/+ HEK293 cells expressing H1. C, the immunoblot in (A) was reacted with anti-CNX antibodies, showing an expected very low percent of surface expression of the ER chaperone. D, quantitation of cell surface protein as a percent of total protein for S1R, H1, and CNX, from the experiments in A–C. The graph represents an average of three independent experiments ± SD, p values ∗ =0.015, ∗∗ =0.01. Student's t test (paired, two-tailed).