FIG. 7.

Probing the topology of SUN1 using myc-tagged SUN1 constructs. (A) Schematic representation of the myc-tagged SUN1 constructs used. Positions of myc tags are shown as hatched boxes. (B to E) U2OS cells were transiently transfected with SUN1 constructs with a myc tag engineered at either the N terminus (B) or the C terminus (C) or internally following residue 355 (D) or 456 (E). The cells were fixed with 4% paraformaldehyde and permeabilized with either Triton X-100 at room temperature (top) or with digitonin at 4°C (bottom) and then costained with anti-SUN1 (left side) and anti-myc 9E10 (right side) antibodies. Scale bar, 10 μm.