Gamma-tubulin complex is necessary for microtubule nucleation at the microtubule organizing centers (MTOCs). Required for the positioning of the gamma-tubulin-containing complex on pre-existing microtubules and for the proper organization of cortical arrays. Part of the gamma-tubulin complex. Gamma-tubulin complex is composed of gamma-tubulin and GCP proteins (e.g. GCP2 and GCP3). Interacts directly with GCP3. Associated to motile complexes in the cytosol that transiently stabilized at fixed locations in the cell cortex (e.g. along the outer periclinal edge of newly formed crosswalls) from which microtubules grow away prior to microtubules nucleation. Colocalizes with gamma-tubulin at the nuclear surface where microtubules are nucleated. Embryonic lethality. Impaired development of male and female gametophytes. Belongs to the TUBGCP family.