Nuclear export and plasma membrane recruitment of the Ste5 scaffold are coordinated with oligomerization and association with signal transduction components.
Nuclear export and plasma membrane recruitment of the Ste5 scaffold are coordinated with oligomerization and association with signal transduction components.
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Ste5 支架的核输出和质膜募集与寡聚化以及与信号转导成分的关联相协调。
DOI：
10.1091/mbc.e02-10-0699
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发表时间：
2003
影响因子：
3.3
通讯作者：
Elion,ElaineA
中科院分区：
文献类型：
--
作者：
Wang,Yunmei;Elion,ElaineA
Ste 5支架通过其RING-H2结构域与质膜上的Gβγ二聚体（Ste 4/Ste 18）结合，激活相关的促分裂原活化蛋白激酶级联反应，这需要Ste 5的预先核穿梭。遗传学证据表明，Ste 5必须寡聚化才能发挥功能，但其对Ste 5功能和定位的影响尚不清楚。在此，我们表明，寡聚化影响Ste 5的活性和本地化。大多数Ste 5是单体的，这表明寡聚化受到严格调控。增加Ste 5寡聚物的库增加与Ste 11的缔合。值得注意的是，Ste 5寡聚体也更有效地从细胞核中输出，通过Ste 11保留在细胞质中，并更好地招募到质膜，导致交配促分裂原活化蛋白激酶级联的组成性激活。共沉淀试验表明，RING-H2结构域是寡聚化的关键决定因素。 突变分析表明，富含亮氨酸的结构域限制了RING-H2结构域的可及性，除了促进Ste 11的结合和激活外，还抑制了出口和招募。我们的研究结果表明，Ste 5的主要形式是一个不可接近的RING-H2结构域和Ste 11结合位点的非活性单体，而活性形式是一个寡聚体，更有效地输出和招募，并具有更容易RING-H2结构域和Ste 11结合位点。
The Ste5 scaffold activates an associated mitogen-activated protein kinase cascade by binding through its RING-H2 domain to a Gβγ dimer (Ste4/Ste18) at the plasma membrane in a recruitment event that requires prior nuclear shuttling of Ste5. Genetic evidence suggests that Ste5 must oligomerize to function, but its impact on Ste5 function and localization is unknown. Herein, we show that oligomerization affects Ste5 activity and localization. The majority of Ste5 is monomeric, suggesting that oligomerization is tightly regulated. Increasing the pool of Ste5 oligomers increases association with Ste11. Remarkably, Ste5 oligomers are also more efficiently exported from the nucleus, retained in the cytoplasm by Ste11 and better recruited to the plasma membrane, resulting in constitutive activation of the mating mitogen-activated protein kinase cascade. Coprecipitation tests show that the RING-H2 domain is the key determinant of oligomerization. Mutational analysis suggests that the leucine-rich domain limits the accessibility of the RING-H2 domain and inhibits export and recruitment in addition to promoting Ste11 association and activation. Our results suggest that the major form of Ste5 is an inactive monomer with an inaccessible RING-H2 domain and Ste11 binding site, whereas the active form is an oligomer that is more efficiently exported and recruited and has a more accessible RING-H2 domain and Ste11 binding site.
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影响因子：
4.8
作者：
Inouye, K;Mizutani, S;Kaziro, Y
通讯作者：
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影响因子：
64.8
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Leeuw, T;Wu, CL;Leberer, E
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影响因子：
--
作者：
Elion,ElaineA
通讯作者：
Elion,ElaineA
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影响因子：
4.8
作者：
Y. Maru;D. Afar;O. Witte;M. Shibuya
通讯作者：
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