The g-Tubulin complex is composed of g Tubulin and the g-Tubulin complex-associated proteins GCP2, GCP3, GCP4, GCP5 and GCP6, all of which are essential components of microtubule organizing centers. g-Tubulin complex components are localized to both the centrosome, where they are involved in microtubule nucleation, and to the cytoplasm, where they exist as soluble complexes that can be recruited to the centrosome as needed. Although the GCP proteins are related, they have distinct roles which contribute to the proper function of the g-Tubulin complex. GCP6 (g-Tubulin complex component 6), also known as TUBGCP6, localizes to the centrosome and is a ubiquitously expressed 1,819 amino acid member of the g-Tubulin complex. Unlike GCP3 and GCP2, GCP6 is not well conserved among eukaryotes. Three isoforms of GCP6 exist due to alternative splicing events.