FIGURE 2.

Chimeric GCPs rescue γTuRC assembly only if they carry the N-terminal domain corresponding to the depleted GCP. Shown is sucrose gradient fractionation of extracts from stable cell lines expressing the chimeras after depletion of the GCPs corresponding to the N- or the C-terminal domain of the chimera. A, chimeras composed of the N-terminal domain of GCP4 fused to the C-terminal domains of GCP 2, 3, 5, or 6 (respectively, N42C, N43C, N45C, and N46C). B, chimeras composed of the C-terminal domain of GCP4 fused to the N-terminal domains of GCP 2, 3, 5, or 6 (respectively, N24C, N34C, N54C, and N64C). γTuRC sedimentation is visualized using a γ-tubulin antibody. C, percentage of γ-tubulin in fraction 7 of the gels shown in A and B; values of siRNA-treated cells, with induction of the chimeras, are shown relative to control cells.