Component of the exocyst complex involved in the docking of exocytic vesicles with fusion sites on the plasma membrane during regulated or polarized secretion. Involved in polarized cell growth and organ morphogenesis. During cytokinesis, involved in cell plate initiation, cell plate maturation and formation of new primary cell wall. The exocyst complex is composed of SEC3, SEC5, SEC6, SEC8, SEC10, EXO70A1 and EXO84B. Localized to globular structures in the perinuclear region. Male gametophytic lethal due to defect in pollen germination and pollen tube growth. Belongs to the SEC15 family. Truncated N-terminus.