Fission Yeast MAP Kinase Is Required for the Increased Securin-Separase Interaction That Rescues Separase Mutants Under Stress
Fission Yeast MAP Kinase Is Required for the Increased Securin-Separase Interaction That Rescues Separase Mutants Under Stress
复制标题
裂殖酵母 MAP 激酶是增加 Securin-Separase 相互作用所必需的，从而拯救压力下的 Separase 突变体
作者：
Y. Kawasaki;Koji Nagao;Takahiro Nakamura;M. Yanagida
姐妹染色单体的分离需要两个步骤的蛋白水解。Securin，分离酶的伴侣和抑制剂，在多聚泛素化后的后期被破坏，并且产生的活化的分离酶切割粘附素亚基Scc 1/Rad 21。形成复合物的裂变酵母securin/Cut 2和separase/Cut 1对于生存力是必不可少的，并且已经分离出许多温度敏感（ts）突变体。我们在这里报告的压力，如1.2 M山梨醇，0.6 M KCl和0.1 M氯化钙在培养基中抑制所有的cut 1突变体和两个的三个cut 2突变体的ts表型检查。这一意外的发现使我们研究了cut 1和cut 2突变体的ts表型如何被增加的压力所拯救。应力引起的时间逮捕在细胞数量的增加，这种逮捕是依赖于Spc 1/Sty 1，但不Rad 3和Mad 2。在分裂周期重新开始之前的2-3小时的停滞期内，securin的水平显著增加，显然伴随着与突变分离酶蛋白的复合物形成的增加。与分离酶结合的Securin被过度磷酸化。胁迫不能挽救坚不可摧的Cut 2和Rad 21突变体。我们假设，压力产生的超伴侣形式的切割2，可以拯救分离酶突变。
Sister chromatid separation requires two steps of proteolysis. Securin, the chaperon and inhibitor of separase, is destructed in anaphase after polyubiquitination, and resulting activated separase cleaves the cohesin subunit Scc1/Rad21. Fission yeast securin/Cut2 and separase/Cut1 that form the complex are essential for viability and a number of temperature-sensitive (ts) mutants have been isolated. We here report that the stresses such as 1.2 M sorbitol, 0.6 M KCl and 0.1 M CaCl2 in the medium suppress the ts phenotypes of all the cut1 mutants and two of the three cut2 mutants examined. This unexpected finding led us to study how the ts phenotypes of cut1 and cut2 mutants were rescued by the increased stresses. The stresses caused a temporal arrest in the cell number increase, and this arrest was dependent on Spc1/Sty1 but not Rad3 and Mad2. During the 2-3 hr arrested period that occurred prior to the re-start of division cycle, the level of securin dramatically increased, apparently accompanying the increased complex formation with mutant separase protein. Securin bound to separase was hyperphosphorylated. The stresses could not rescue the indestructible Cut2 and Rad21 mutants. We postulate that the stresses produce the hyperchaperonic form of Cut2 that can rescue separase mutations.
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影响因子：
4
作者：
I. Hagan;J. Hyams
通讯作者：
I. Hagan;J. Hyams
影响因子：
10.5
作者：
CohenFix, O;Peters, JM;Koshland, D
通讯作者：
Koshland, D
影响因子：
3.3
作者：
Shiozaki, K;Shiozaki, M;Russell, P
通讯作者：
Russell, P
DOI：
10.1073/pnas.94.15.7965
发表时间：
1997-07-22
影响因子：
11.1
作者：
He, XW;Patterson, TE;Sazer, S
通讯作者：
Sazer, S
影响因子：
56.9
作者：
Kim, SH;Lin, DP;Matsumoto, T
通讯作者：
Matsumoto, T