Schematic representation of the vector used for Ecotin-Ubiquitin-FLS expression. Amino acids of the corresponding genes are numbered. Full-length ecotin with the intrinsic signal sequence (1–20) was cloned upstream of mouse ubiquitin B (ubi, 2–76), followed by the FLS (1–26) target peptide. The cleavage site for a deubiquitinating enzyme (DUB) is indicated with an arrow. A SacII cleavage was introduced at the ubiquitin C-terminus by PCR. t0, transcription termination region.