Pereira G, Höfken T, Grindlay J, Manson C, Schiebel E
The Beatson Institute for Cancer Research, CRC Beatson Laboratories, Glasgow, United Kingdom.
Mol Cell. 2000 Jul;6(1):1-10.
Bfa1p and Bub2p are spindle checkpoint proteins that likely have GTPase activation activity and are associated with the budding yeast spindle pole body (SPB). Here, we show that Bfa1p and Bub2p bind the Ras-like GTPase Tem1p, a component of the mitotic exit network, to the cytoplasmic face of the SPB that enters the bud, whereas the GDP/GTP exchange factor Lte1p is associated with the cortex of the bud. Migration of the SPB into the bud probably allows activation of Tem1p through Lte1p, thereby linking nuclear migration with mitotic exit. Since components of the Bub2p checkpoint are conserved in other organisms, we propose that the position of the SPB or mammalian centrosome controls the timing of mitotic exit.
Bfa1p和Bub2p是纺锤体检查点蛋白，可能具有GTPase激活活性，并与芽殖酵母的纺锤体极体（SPB）相关。在此，我们表明Bfa1p和Bub2p将有丝分裂退出网络的一个组成部分、类Ras GTPase Tem1p结合到进入芽体的SPB的细胞质面上，而GDP/GTP交换因子Lte1p则与芽体的皮质相关。SPB迁移到芽体中可能允许Tem1p通过Lte1p被激活，从而将核迁移与有丝分裂退出联系起来。由于Bub2p检查点的组分在其他生物体中是保守的，我们提出SPB或哺乳动物中心体的位置控制有丝分裂退出的时间。
