Involved in microtubules reorganization during spindle and phragmoplast development. Required for gamma-tubulin localization during mitosis. Part of the augmin complex composed of 8 subunits (PubMed:22505726). The complex acts on microtubules and interacts with gamma-tubulin in spindles and the phragmoplast (PubMed:22505726). Interacts with AUG1 (PubMed:21750235). Preferentially localizes to microtubules minus ends. Lethal when homozygous. Belongs to the HAUS3 family.