Globular tubulin subunits comprise the microtubule building block, with α/β-tubulin heterodimers forming the tubulin subunit common to all eukaryotic cells. As a critical part of the microtubule-organizing center (MTOC), the third member of the tubulin superfamily, γ-tubulin, is required for microtubule nucleation as well as centrosome duplication and spindle assembly (1,2, reviewed in 3). γ-tubulin forms complexes of two different sizes: γ-tubulin small complex (γ-TuSC) and the larger γ-tubulin ring complex (γ-TuRC). Each complex consists of a number of γ-tubulin complex proteins (GCPs) with γ-tubulin itself being considered GCP1. GCP2-6 all share sequence similarity in 5 different regions and it is thought that these areas could play a role in the proper folding of the proteins (4). γ-TuSC is composed of two γ-tubulin molecules as well as GCP2 and GCP3. γ-TuRC is made up of a ring of multiple copies of γ-TuSC in addition to GCP4, 5, and 6. Another protein, GCP-WD/NEDD1, which lacks sequence similarity with the other GCPs, associates with the γ-TuRC. GCP-WD/NEDD1 has been shown to regulate localization of the γ-TuSC to spindles and centrosomes (5-8). In mammals, phosphorylation of γ-tubulin at Ser131 by SADB controls the activity of the γ-TuRC. The hypothesis is that this phosphorylation stabilizes the protein in a conformation that stimulates centrosome amplification (9).
2 . Loncarek, J. and Khodjakov, A. (2009) Mol Cells 27, 135-42.
3 . Wiese, C. and Zheng, Y. (2006) J Cell Sci 119, 4143-53.
4 . Murphy, S.M. et al. (2001) Mol Biol Cell 12, 3340-52.
5 . Raynaud-Messina, B. and Merdes, A. (2007) Curr Opin Cell Biol 19, 24-30.
6 . Schiebel, E. (2000) Curr Opin Cell Biol 12, 113-8.
7 . Lüders, J. et al. (2006) Nat Cell Biol 8, 137-47.
8 . Haren, L. et al. (2009) PLoS One 4, e5976.
9 . Alvarado-Kristensson, M. et al. (2009) Nat Cell Biol 11, 1081-92.
Western blot analysis of extracts from various cell lines using γ-Tubulin Antibody.Western blot analysis of extracts from various cell lines using γ-Tubulin Antibody.
使用γ-Tubulin Antibody，免疫印迹（Western Blot）分析不同细胞中γ-Tubulin。