PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity.
PAR3 and aPKC regulate Golgi organization through CLASP2 phosphorylation to generate cell polarity.
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DOI：
10.1091/mbc.e14-09-1382
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发表时间：
2015-02-15
影响因子：
3.3
通讯作者：
Kaibuchi K
中科院分区：
文献类型：
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作者：
Matsui T;Watanabe T;Matsuzawa K;Kakeno M;Okumura N;Sugiyama I;Itoh N;Kaibuchi K
PAR复合物（PAR 3、PAR 6和aPKC）在细胞极性的建立中起着重要作用。另一种极性蛋白CLASP 2直接与PAR 3结合并被aPKC磷酸化。通过CLASP 2磷酸化，aPKC和PAR 3调节CLASP 2定位到trans-Golgi网络，从而控制Golgi组织。高尔基体的组织对于细胞极化及其维持是必不可少的。极性调节剂PAR复合物（PAR 3、PAR 6和aPKC）在细胞极化的几个过程中起关键作用。然而，PAR复合体如何参与调节高尔基体的组织仍然是未知的。在这里，我们展示了PAR复合物与CLASP 2的功能性串扰，CLASP 2是一种微管加末端跟踪蛋白，参与组织高尔基带。CLASP 2直接与PAR 3相互作用，并被aPKC磷酸化。在上皮细胞中，PAR 3或aPKC的敲低诱导CLASP 2在trans-Golgi网络（TGN）处的异常积累，伴随着高尔基带组织的破坏。抑制PAR 3-CLASP 2相互作用的CLASP 2突变体的表达破坏了高尔基带的组织。已知CLASP 2通过其与TGN蛋白GCC 185的相互作用定位于TGN。这种相互作用受到aPKC介导的CLASP 2磷酸化的抑制。此外，nonphosphorylatable突变体增强了CLASP 2与GCC 185的共定位，从而扰乱了高尔基体的组织。基于这些观察，我们提出PAR 3和aPKC通过CLASP 2磷酸化控制高尔基体的组织。
A PAR complex (PAR3, PAR6, and aPKC) plays a central role in the establishment of cell polarity. Another polarity protein, CLASP2, binds directly with PAR3 and is phosphorylated by aPKC. Through CLASP2 phosphorylation, aPKC and PAR3 regulate the localization of CLASP2 to the trans-Golgi network, thereby controlling the Golgi organization. The organization of the Golgi apparatus is essential for cell polarization and its maintenance. The polarity regulator PAR complex (PAR3, PAR6, and aPKC) plays critical roles in several processes of cell polarization. However, how the PAR complex participates in regulating the organization of the Golgi remains largely unknown. Here we demonstrate the functional cross-talk of the PAR complex with CLASP2, which is a microtubule plus-end–tracking protein and is involved in organizing the Golgi ribbon. CLASP2 directly interacted with PAR3 and was phosphorylated by aPKC. In epithelial cells, knockdown of either PAR3 or aPKC induced the aberrant accumulation of CLASP2 at the trans-Golgi network (TGN) concomitantly with disruption of the Golgi ribbon organization. The expression of a CLASP2 mutant that inhibited the PAR3-CLASP2 interaction disrupted the organization of the Golgi ribbon. CLASP2 is known to localize to the TGN through its interaction with the TGN protein GCC185. This interaction was inhibited by the aPKC-mediated phosphorylation of CLASP2. Furthermore, the nonphosphorylatable mutant enhanced the colocalization of CLASP2 with GCC185, thereby perturbing the Golgi organization. On the basis of these observations, we propose that PAR3 and aPKC control the organization of the Golgi through CLASP2 phosphorylation.