Cytokinesis involves a nontranscriptional function of the Hippo pathway effector YAP.
Cytokinesis involves a nontranscriptional function of the Hippo pathway effector YAP.
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DOI：
10.1126/scisignal.aaa9227
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发表时间：
2016-03-01
影响因子：
7.3
通讯作者：
Brugge JS
中科院分区：
文献类型：
--
作者：
Bui DA;Lee W;White AE;Harper JW;Schackmann RC;Overholtzer M;Selfors LM;Brugge JS
YAP是一种转录辅助激活因子，控制器官的扩张和分化，并在间期细胞中被HIPPO途径抑制。在这里，我们证明，在有丝分裂过程中，YAP定位于参与胞质分裂的中体和纺锤形亚细胞结构，胞质分裂是细胞骨架收缩产生两个子细胞的过程。此外，YAP被CDK1磷酸化，CDK1是一种促进细胞周期进程的激酶。通过shRNA敲除YAP或表达非磷酸化形式的YAP延迟了子代细胞的分离(称为脱落)，并诱导了与收缩力增加、膜气泡和凸起相关的细胞质分裂表型，以及纺锤体方向的异常。因此，这些缺陷导致多核、微核和非整倍体的频率增加。YAP是在胞质分裂过程中调节收缩的蛋白质的适当定位所必需的，这些蛋白质包括ECT2、MGACGap、ANLIN和RHOA。此外，YAP的缺失增加了肌球蛋白轻链的磷酸化，有望激活肌球蛋白II的收缩活性，肌球蛋白II是参与胞质分裂的分子马达。极性支架蛋白PATJ与YAP共沉淀，并与YAP共定位于胞质分裂中段，PATJ表型被敲除，导致YAP缺失或表达不可磷酸化的YAP突变体引起的细胞动力学缺陷和纺锤体取向改变。综上所述，这些结果揭示了YAP在有丝分裂过程中通过与极性蛋白PATJ相互作用而在细胞质机制的适当组织中发挥的意想不到的作用。
YAP is a transcriptional coactivator that controls organ expansion and differentiation and is inhibited by the Hippo pathway in cells in interphase. Here, we demonstrated that, during mitosis, YAP localized to the midbody and spindle, subcellular structures that are involved in cytokinesis, the process by which contraction of the cytoskeleton produces two daughter cells. Furthermore, YAP was phosphorylated by CDK1, a kinase that promotes cell cycle progression. Knockdown of YAP by shRNA or expression of a nonphosphorylatable form of YAP delayed the separation of daughter cells (called abscission) and induced a cytokinesis phenotype associated with increased contractile force, membrane blebbing and bulges, and abnormal spindle orientation. Consequently, these defects led to an increased frequency of multinucleation, micronuclei, and aneuploidy. YAP was required for proper localization of proteins that regulate contraction during cytokinesis, including ECT2, MgcRacGap, Anillin, and RHOA. In addition, depletion of YAP increased the phosphorylation of myosin light chain, which would be expected to activate the contractile activity of myosin II, the molecular motor involved in cytokinesis. The polarity scaffold protein PATJ coprecipitated with YAP and colocalized with YAP at the cytokinesis midbody, and knockdown of PATJ phenocopied the cytokinetic defects and spindle orientation alterations induced by either YAP depletion or expression of a nonphosphorylatable YAP mutant. Together, these results reveal an unanticipated role for YAP in the proper organization of the cytokinesis machinery during mitosis through interaction with the polarity protein PATJ.