Fig. 1.

Localization and activity of ECE-1 isoforms. (A) In KNRK cells, ECE-1a–d-GFP colocalized with EEA1 (arrows); ECE-1a-GFP and ECE-1c-GFP were also at the plasma membrane (arrowheads). (B) In KNRK cells, ECE-1a–d-GFP colocalized with Rab5aQ79L-CFP in enlarged endosomes. (C and D) In HEK cells, immunoreactive ECE-1b/d colocalized with EEA1 (C) and Rab5aQ79L-GFP (D). (Scale bars: A–D, 10 μm.) (E) Intact KNRK-NK₁R cells hydrolyzed McaBK2 at 1/20th the rate of KNRK-NK₁R+ECE-1a cells. (F) Total ECE-1 activity was similar in all KNRK cells, with highest intracellular activity of ECE-1b and ECE-1d.