Sobel S G, Snyder M
Department of Biology, Yale University, New Haven, Connecticut 06520-8103, USA.
J Cell Biol. 1995 Dec;131(6 Pt 2):1775-88. doi: 10.1083/jcb.131.6.1775.
A Saccharomyces cerevisiae gamma-tubulin-related gene, TUB4, has been characterized. The predicted amino acid sequence of the Tub4 protein (Tub4p) is 29-38% identical to members of the gamma-tubulin family. Indirect immunofluorescence experiments using a strain containing an epitope-tagged Tub4p indicate that Tub4p resides at the spindle pole body throughout the yeast cell cycle. Deletion of the TUB4 gene indicates that Tub4p is essential for yeast cell growth. Tub4p-depleted cells arrest during nuclear division; most arrested cells contain a large bud, replicated DNA, and a single nucleus. Immunofluorescence and nuclear staining experiments indicate that cells depleted of Tub4p contain defects in the organization of both cytoplasmic and nuclear microtubule arrays; such cells exhibit nuclear migration failure, defects in spindle formation, and/or aberrantly long cytoplasmic microtubule arrays. These data indicate that the S. cerevisiae gamma-tubulin protein is an important SPB component that organizes both cytoplasmic and nuclear microtubule arrays.
已对酿酒酵母中一个与γ-微管蛋白相关的基因TUB4进行了表征。Tub4蛋白(Tub4p)的预测氨基酸序列与γ-微管蛋白家族成员的序列有29%至38%的同一性。使用含有表位标签的Tub4p的菌株进行的间接免疫荧光实验表明,Tub4p在整个酵母细胞周期中都位于纺锤体极体上。TUB4基因的缺失表明Tub4p对酵母细胞生长至关重要。缺乏Tub4p的细胞在核分裂过程中停滞;大多数停滞的细胞含有一个大芽、复制的DNA和一个单核。免疫荧光和核染色实验表明,缺乏Tub4p的细胞在细胞质和核微管阵列的组织上存在缺陷;这些细胞表现出核迁移失败、纺锤体形成缺陷和/或异常长的细胞质微管阵列。这些数据表明,酿酒酵母γ-微管蛋白是一种重要的纺锤体极体成分,可组织细胞质和核微管阵列。