Figure 4.

The interaction of nuclear lamins and endoplasmic reticulum (ER) proteins. (a and b) Normal and HGPS skin fibroblasts were transfected with a Sln expression vector tagged with HA (i.e., Sln‐HA). Cells were fixed after 96 hr of transfection and immunofluorescent stained to visualize HA (green), cell endogenous SERCA2 or lamin A (red), and lamin B (gray). The nuclei were counterstained using Hoechst 33,342 (blue). Transverse intensity line scans along the white lines of the corresponding cell images are presented on the right. (c) HEK293TN cells were co‐transfected with Sln‐HA, FLAG‐progerin and/or FLAG‐lamin A. Cells transfected with (+) or without (−) the indicated expression plasmids are noted at the top of the Western blot profiles. Cell lysates were immunoprecipitated using mouse anti‐HA and mouse anti‐FLAG agarose, respectively. The cell lysate input and co‐IP products were analyzed by SDS‐PAGE followed by immunoblotting with the indicated antibodies. The signals of the co‐immunoprecipitated Calnexin and SERCA2 were quantified and shown below the immunostaining profiles