Figure 1.

Schematic representation of constructs. (A) Kex2p constructs. KEX2HA was obtained by adding two tandem copies of the HA epitope (hatched box) to the 3′ end of the KEX2 coding sequence. Δprokex2HA encodes a protein in which Ser²³ is adjacent to Leu¹¹⁰ and thus lacks the entire proregion. Preprokex2 encodes the 109 N-terminal amino acids of wild-type Kex2p protein. The transmembrane domain is shown as a black box, and the proregion is shown as a dotted box. The sequence of the signal peptide and partial sequence of the proregion are presented above the first construct. The sequence of the HA epitope is presented below the second construct in bold characters. (B) Fusions of PC proregions and Kex2p signal peptide. The pre[TR]kex2 encoding the Kex2p signal peptide bearing a C-terminal Thr-Arg doublet was fused to the proregion of either Kex2p or human furin, rat PC7, human PACE4, rat PC4, mouse PC1, mouse PC2, and human PC5.