Kin2, the Budding Yeast Ortholog of Animal MARK/PAR-1 Kinases, Localizes to the Sites of Polarized Growth and May Regulate Septin Organization and the Cell Wall.
Kin2, the Budding Yeast Ortholog of Animal MARK/PAR-1 Kinases, Localizes to the Sites of Polarized Growth and May Regulate Septin Organization and the Cell Wall.
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Kin2 是动物 MARK/PAR-1 激酶的出芽酵母直系同源物，定位于极化生长位点并可能调节 Septin 组织和细胞壁
DOI：
10.1371/journal.pone.0153992
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Gao XD
中科院分区：
文献类型：
--
作者：
Yuan SM;Nie WC;He F;Jia ZW;Gao XD
MARK/PAR-1蛋白激酶在动物细胞极化中起重要作用。Kin 1和Kin 2是芽殖酵母Saccharomyces cerevisiae中的一对MARK/PAR-1同源基因。它们参与分泌和ER应激反应的调节。然而，这两种激酶的亚细胞定位以及它们是否具有其他细胞功能都不清楚。在这里，我们表明，Kin 2定位到除了定位在质膜上的极化生长的网站。极性位点的定位由两个靶向结构域TD 1和TD 2介导。TD 1位于N-末端区域，跨越蛋白激酶结构域，而TD 2位于C-末端，覆盖KA 1结构域。我们还表明，过量的Kin 2活性损害生长，septin组织，和几丁质沉积在细胞壁中。TD 1和TD 2都有助于此功能。此外，我们发现，Kin 2的C-末端区域与Cdc 11，隔蛋白亚基，和Pea 2，已知在隔蛋白组织中发挥作用的极化体的一个组成部分相互作用。这些结果表明，Kin 2可能在调节细胞骨架和细胞壁中发挥作用。最后，我们表明，Kin 2的C-末端区域与Rho 3，Rho GTdR相互作用，而Kin 2的N-末端区域与Bmh 1，14-3-3蛋白相互作用。我们推测，在体内，Kin 2可能受到Bmh 1，Rho 3或Pea 2的调节。我们的研究为Kin 2的定位、功能和调控提供了新的见解。
MARK/PAR-1 protein kinases play important roles in cell polarization in animals. Kin1 and Kin2 are a pair of MARK/PAR-1 orthologs in the budding yeast Saccharomyces cerevisiae. They participate in the regulation of secretion and ER stress response. However, neither the subcellular localization of these two kinases nor whether they may have other cellular functions is clear. Here, we show that Kin2 localizes to the sites of polarized growth in addition to localization on the plasma membrane. The localization to polarity sites is mediated by two targeting domains—TD1 and TD2. TD1 locates in the N-terminal region that spans the protein kinase domain whereas TD2 locates in the C-terminal end that covers the KA1 domain. We also show that an excess of Kin2 activity impaired growth, septin organization, and chitin deposition in the cell wall. Both TD1 and TD2 contribute to this function. Moreover, we find that the C-terminal region of Kin2 interacts with Cdc11, a septin subunit, and Pea2, a component of the polarisome that is known to play a role in septin organization. These findings suggest that Kin2 may play a role in the regulation of the septin cytoskeleton and the cell wall. Finally, we show that the C-terminal region of Kin2 interacts with Rho3, a Rho GTPase, whereas the N-terminal region of Kin2 interacts with Bmh1, a 14-3-3 protein. We speculate that Kin2 may be regulated by Bmh1, Rho3, or Pea2 in vivo. Our study provides new insight in the localization, function, and regulation of Kin2.