Ste5 tethers multiple protein kinases in the MAP kinase cascade required for mating in S. cerevisiae.
Ste5 tethers multiple protein kinases in the MAP kinase cascade required for mating in S. cerevisiae.
复制标题
Ste5 在酿酒酵母交配所需的 MAP 激酶级联中连接多种蛋白激酶。
DOI：
10.1016/0092-8674(94)90427-8
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发表时间：
1994
期刊：
影响因子：
64.5
通讯作者：
Elion,EA
中科院分区：
文献类型：
--
作者：
Choi,KY;Satterberg,B;Lyons,DM;Elion,EA
Ste5 是一种 Znz+ 指状蛋白，被认为在酿酒酵母交配所需的保守 MAP 激酶级联中，先于三种激酶 Stell（一种 MEKK）、Ste7（一种 MEK）和 Fus3（一种 MAPK）发挥作用。在这里，我们提供的证据表明 Ste5 形成了一种多激酶复合物，该复合物连接这些激酶以有效激活 Fus3。通过双杂交分析，Stell、Ste7和Fus3与Ste5的不同结构域相关联，而另一种MAPK Kssl与FUSS与相同的结构域相关联，因此暗示Ste5同时结合MEKK、MEK和MAPK。 Ste5 与 Stell、Fusl 和 Ste7 的低磷酸化形式共纯化，所有四种蛋白质在甘油梯度中共沉积，就像在一个大复合物中一样。 Ste5 还增加与 Ste7 和 Fus3 复合的 Stel 1 的量，并且是 Stell 发挥作用所必需的。这些结果证实了一种新的信号转导成分，该成分在单个级联中物理连接多个激酶。
Ste5 is a Znz+ finger-like protein thought to function before three kinases, Stell (a MEKK), Ste7 (a MEK), and Fus3 (a MAPK), in a conserved MAP kinase cascade required for mating in S. cerevisiae. Here, we present evidence that Ste5 forms a multikinase complex that joins these kinases for efficient Fus3 actlvation. By two-hybrid analysis, Stell, Ste7, and Fus3 associate with different domains of Ste5, while Kssl, another MAPK, associates with the same domain as FUSS, thus implying that Ste5 simultaneously binds a MEKK, MEK, and MAPK. Ste5 copurifies with Stell, Fusl, and a hypophosphorylated form of Ste7, and all four proteins cosediment in a glycerol gradient as if in a large complex. Ste5 also Increases the amount of Stel 1 complexed to Ste7 and Fus3 and is required for Stell to function. These results substantiate a novel signal transduction component that physically links multiple kinases within a single cascade.