Bacterially purified MBP-Cnn-T-N fragments coimmunoprecipitate γ-tubulin ring complexes. (A) Western blot showing results of anti-MBP co-IP from embryo extracts expressing GFP-tagged Grip proteins (homologues of GCP4,5,6), either supplemented (+) or not supplemented (−) with MBP-Cnn-T-N, as indicated. Blots were probed with anti-GFP, anti-Grip71, and anti–γ-tubulin antibodies as indicated. When using MBP-Cnn-T-N, γ-tubulin, and Grip71, as well as Grip75, 128, or 163, are coimmunoprecipitated. (B) Mass spectrometry results from IPs with MBP-Cnn-T-N showing the presence of various γ-TuRC components. Note that Mzt1 is not expressed within embryos. Results of a control experiment on Grip75-GFP embryo extract not supplemented with any MBP-Cnn-T-N fragment are also shown. Numbers indicate emPAI scores as a proxy for protein abundance. Grip84 (A) and Grip84 (E) represent two different isoforms of Grip84 (promoters 1 and 2, respectively).