Gamma-tubulin complex is necessary for microtubule nucleation at the centrosome. Gamma-tubulin complex is composed of gamma-tubulin, TUBGCP2, TUBGCP3, TUBGCP4, TUBGCP5 and TUBGCP6. Interacts with CDK5RAP2; the interaction is leading to centrosomal localization of TUBGCP3 and CDK5RAP2. Interacts with NIN (via N-terminus); the interaction may promote recruitment of the gamma-tubulin ring complex to the centrosome (By similarity). Experimental confirmation may be lacking for some isoforms. Ubiquitously expressed. Belongs to the TUBGCP family.