Tubulin Gamma Complex Associated protein 4 (TUBgCP4)

GCP4 deduced 667-amino acid protein has a calculated molecular mass of 76 kD and shows sequence identity with the C-terminal regions of human centrosomal proteins 103p (TUBGCP2) and 104p (TUBGCP3).By coimmunoprecipitation, Fava et al. (1999) demonstrated that GCP4 associated in complex with gamma-tubulin (TUBG1) in mammalian cells and Xenopus oocytes. Immunofluorescence showed that GCP4 colocalized with gamma-tubulin at centrosomes in mammalian cells. During mitosis, Gcp4 localized to the metaphase spindle and showed transiently increased expression on centrosomes. Gcp4 was present in Xenopus sperm basal bodies, and antibody depletion experiments showed that it was necessary for aster nucleation by sperm basal bodies.