Schramm C, Elliott S, Shevchenko A, Schiebel E
The Beatson Institute for Cancer Research, CRC Beatson Laboratories, Glasgow G61 1BD, UK.
EMBO J. 2000 Feb 1;19(3):421-33. doi: 10.1093/emboj/19.3.421.
In budding yeast, microtubules are organized by the spindle pole body (SPB), which is embedded in the nuclear envelope via its central plaque structure. Here, we describe the identification of BBP1 in a suppressor screen with a conditional lethal allele of SPC29. Bbp1p was detected at the central plaque periphery of the SPB and bbp1-1 cells were found to be defective in SPB duplication. bbp1-1 cells extend their satellite into a duplication plaque like wild-type cells; however, this duplication plaque then fails to insert properly into the nuclear envelope and does not assemble a functional inner plaque. This function in SPB duplication is probably fulfilled by a stable complex of Bbp1p and Mps2p, a nuclear envelope protein that is also essential for duplication plaque insertion. In addition, we found that Bbp1p interacts with Spc29p and the half-bridge component Kar1p. These interactions are likely to play a role in connecting the SPB with the nuclear envelope and the central plaque with the half-bridge.
在出芽酵母中，微管由纺锤体极体（SPB）组织，纺锤体极体通过其中心板结构嵌入核膜。在此，我们描述了在对SPC29的条件致死等位基因进行的抑制子筛选中对BBP1的鉴定。在SPB的中心板周边检测到Bbp1p，并且发现bbp1-1细胞在SPB复制方面存在缺陷。bbp1-1细胞会像野生型细胞一样将其卫星延伸成复制斑；然而，这个复制斑随后无法正确插入核膜，也不能组装功能性的内板。SPB复制中的这一功能可能由Bbp1p和Mps2p的稳定复合物实现，Mps2p是一种核膜蛋白，对复制斑的插入也至关重要。此外，我们发现Bbp1p与Spc29p和半桥组件Kar1p相互作用。这些相互作用可能在将SPB与核膜以及中心板与半桥连接起来方面发挥作用。
