Figure 4.

The presence of a cleavable N-terminal tail on PC1 is necessary for plasma membrane localization. An N-terminal deletion construct of PC1 (PC1-NTD) was prepared by deleting 2760 amino acids from the N terminus of PC1 (A). Expressing this construct in HEK293 cells yielded a fragment of the expected size for full-length PC1-NTD (arrow in B), with a very small amount of GPS-cleaved product (B, arrowhead denotes C-terminal cleavage fragment). PC1-NTD was not brought to the plasma membrane by coexpression with PC2, as seen using transfection and exposure conditions that are sufficient to produce localization of wild-type PC1 to the surface (C).