γ-Tubulin complexes and their role in microtubule nucleation

Abstract

Publisher Summary This chapter discusses the purification and characterization of γ-tubulin ring complex (γTuRC) and γ-tubulin small complex (γTuSC) and the function of γTuRC at the centrosome. The proposed mechanism of γTuRC-mediated microtubule nucleation is also reviewed. The identification of γ-tubulin and its essential role in microtubule nucleation is a major breakthrough in the study of microtubules and centrosomes. The subsequent purification of γTuRC provides the much-needed tool to investigate the role of γ-tubulin in microtubule nucleation and centrosome assembly. γTuRC is essential for both microtubule nucleation and formation of a functional centrosome. Further characterization of the γTuRC components helps to study the assembly of γTuRC and its recruitment to the centrosome. It provides an understanding of centrosome assembly, which is an essential process for proper cell division. The mechanism of microtubule nucleation by γ-tubulin comes from both biochemical and structural studies. γ-Tubulin exists as a complex with other proteins inside the cell; in certain cell types, multiple γ-tubulin complexes of different sizes co-exist. Antibody affinity production of γ-tubulin complexes from Drosophila embryos and Xenopus egg extracts is diagrammatically represented in the chapter.