Tubulin Gamma Complex Associated protein 6 (TUBgCP6)

TUBGCP6 is part of a large multisubunit complex required for microtubule nucleation at the centrosome.The deduced GCP6 protein has a calculated molecular mass of 244 kD. It contains 5 regions conserved in other gamma-tubulin complex proteins, as well as an additional sequence between conserved regions II and III containing 9 tandem repeats of a 27-amino acid sequence. These repeats are present in GCP6 orthologs of other vertebrates, but are missing in the Drosophila GCP6 ortholog, Drip163. Immunofluorescence microscopy of human osteosarcoma cells localized GCP6 at the foci of microtubule asters in interphase cells and at spindle poles of mitotic cells, colocalizing with gamma-tubulin. Centrosomal GCP6 staining remained in the absence of microtubules, indicating that GCP6 is a core component of centrosomes.