The fission yeast SPB component Cut12 links bipolar spindle formation to mitotic control
The fission yeast SPB component Cut12 links bipolar spindle formation to mitotic control
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DOI：
10.1101/gad.12.7.927
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发表时间：
1998-04-01
影响因子：
10.5
通讯作者：
Hagan, IM
中科院分区：
文献类型：
--
作者：
Bridge, AJ;Morphew, M;Hagan, IM
在分裂酵母有丝分裂过程中，复制的纺锤体极体（SPB）使微管阵列成核，这些微管阵列相互交叉以形成有丝分裂纺锤体。cut12.1突变体形成单极有丝分裂纺锤体，染色体分离失败，并且突变体经历致死性胞质分裂。cut 12（+）基因编码一种新的62 kD蛋白，具有两个预测的卷曲螺旋区域，以及一个p34（cdc 2）和两个MAP激酶的磷酸化位点。Cut 12在整个细胞周期中定位于SPB，主要围绕间期SPB的内面，邻近细胞核。cut 12（+）与stf 1（+）等位; stf1.1是一种功能获得性突变，绕过了Cdc 25酪氨酸磷酸酶的需要，Cdc 25酪氨酸磷酸酶通常去磷酸化并激活p34（cdc 2）/细胞周期蛋白B激酶以促进有丝分裂的开始。表达携带stf1.1突变的cut 12（+）cDNA也抑制了cdc25.22。cut12.1中的纺锤体缺陷因cdc25.22突变而加剧，stf1.1细胞在高温下在cdc25.22背景下形成缺陷纺锤体。我们认为Cut 12可能是p34（cdc 2）有丝分裂激酶的调节剂或底物。
During fission yeast mitosis, the duplicated spindle pole bodies (SPBs) nucleate microtubule arrays that interdigitate to form the mitotic spindle. cut12.1 mutants form a monopolar mitotic spindle, chromosome segregation fails, and the mutant undergoes a lethal cytokinesis. The cut12(+) gene encodes a novel 62-kD protein with two predicted coiled coil regions, and one consensus phosphorylation site for p34(cdc2) and two for MAP kinase. Cut12 is localized to the SPB throughout the cell cycle, predominantly around the inner face of the interphase SPB, adjacent to the nucleus. cut12(+) is allelic to stf1(+); stf1.1 is a gain-of-function mutation bypassing the requirement for the Cdc25 tyrosine phosphatase, which normally dephosphorylates and activates the p34(cdc2)/cyclin B kinase to promote the onset of mitosis. Expressing a cut12(+) cDNA carrying the stf1.1 mutation also suppressed cdc25.22. The spindle defect in cut12.1 is exacerbated by the cdc25.22 mutation, and stf1.1 cells formed defective spindles in a cdc25.22 background at high temperatures. We propose that Cut12 may be a regulator or substrate of the p34(cdc2) mitotic kinase.