The kinase domain of CK1 enzymes contains the localization cue essential for compartmentalized signaling at the spindle pole
The kinase domain of CK1 enzymes contains the localization cue essential for compartmentalized signaling at the spindle pole
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DOI：
10.1091/mbc.e18-02-0129
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发表时间：
2018-07-01
影响因子：
3.3
通讯作者：
Gould, Kathleen L.
中科院分区：
文献类型：
--
作者：
Elmore, Zachary C.;Guillen, Rodrigo X.;Gould, Kathleen L.
CK 1蛋白激酶参与多种生物学过程，但它们如何在区室化信号事件中发挥作用在很大程度上是未知的。Hhp 1和Hhp 2（Hhp 1/2）是粟酒裂殖酵母中可溶性CK 1家族成员。它们的功能之一是在有丝分裂检查点停滞期间抑制分隔起始网络（SIN）。SIN由Sid 4组装在纺锤体极体（SPB）处，尽管Hhp 1/2在那里共定位，但尚不知道它们如何靶向那里或它们的SPB定位是否是SIN抑制所需的。在这里，我们建立了Hhp 1/2定位在整个细胞周期的SPBs，以及细胞核，细胞尖端，和分裂网站。我们发现，他们的催化结构域，但不是他们的酶功能被用于SPB的目标，这种定位策略是保守的人CK 1d/e定位到中心体。此外，我们查明的Hhp 1催化结构域中的氨基酸需要SPB的相互作用，这些残基的突变破坏Hhp 1与核心SPB蛋白Ppc 89协会，并在设置纺锤体应力的胞质分裂抑制。总之，这些数据使我们能够定义CK 1酶用于靶向特定细胞区域进行区室化信号传导的分子机制。
CK1 protein kinases contribute to multiple biological processes, but how they are tailored to function in compartmentalized signaling events is largely unknown. Hhp1 and Hhp2 (Hhp1/2) are the soluble CK1 family members in Schizosaccharomyces pombe. One of their functions is to inhibit the septation initiation network (SIN) during a mitotic checkpoint arrest. The SIN is assembled by Sid4 at spindle pole bodies (SPBs), and though Hhp1/2 colocalize there, it is not known how they are targeted there or whether their SPB localization is required for SIN inhibition. Here, we establish that Hhp1/2 localize throughout the cell cycle to SPBs, as well as to the nucleus, cell tips, and division site. We find that their catalytic domains but not their enzymatic function are used for SPB targeting and that this targeting strategy is conserved in human CK1d/e localization to centrosomes. Further, we pinpoint amino acids in the Hhp1 catalytic domain required for SPB interaction; mutation of these residues disrupts Hhp1 association with the core SPB protein Ppc89, and the inhibition of cytokinesis in the setting of spindle stress. Taken together, these data have enabled us to define a molecular mechanism used by CK1 enzymes to target a specific cellular locale for compartmentalized signaling.