Component of the exocyst complex involved in the docking of exocytic vesicles with fusion sites on the plasma membrane. The exocyst complex is composed of EXOC1, EXOC2, EXOC3, EXOC4, EXOC5, EXOC6, EXOC7 and EXOC8. Interacts with EEF1A1. Interacts with SLC6A9; interaction increases the transporter capacity of SLC6A9 probably by promoting its insertion into the cell membrane. Colocalizes with CNTRL/centriolin at the midbody ring. Localizes in cell membrane in the presence of SLC6A9. Belongs to the SEC3 family.