Endosidin2 (ES2) binds to the exocyst component of 70 kDa (EXO70) subunit of the exocyst complex with a Kd of 253 μM. Endosidin2 inhibits exocytosis and endosomal recycling in both plant and human cells and enhances plant vacuolar trafficking. Endosidin2 is a valuable new tool for the study of exocytosis.