REGULATION AND FUNCTION OF KIBRA IN THE HIPPO SIGNALING PATHWAY

KIBRA 在 HIPPO 信号通路中的调节和功能

• 批准号: 8360441
• 负责人: Jixin Dong
• 金额: $ 27.19万
• 依托单位: UNIVERSITY OF NEBRASKA MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8360441
• 关键词: Affect; Cells; Centrosome; Chromosomes; Drosophila genus; Funding; Grant; Half-Life; Human; Mammalian Cell; Microtubules; Mitosis; Mus; National Center for Research Resources; Nebraska; Phosphorylation; Phosphotransferases; Principal Investigator; Proteins; RNA Interference; Regulation; Research; Research Infrastructure; Resources; Signal Pathway; Signal Transduction; Source; Structure; Transfection; United States National Institutes of Health; cost; human STK6 protein

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. KIBRA is a new component of the Hippo signaling pathway in Drosophila. Mechanisms by which KIBRA affects Hippo signaling and the function of KIBRA in mammalian cells are not clear. We demonstrated that KIBRA associates with and activates Lats1and Lats2. In addition, we showed that transfection of RNAi specific for KIBRA decreases and over-expression of KIBRA increases the cellular level of phosphorylated YAP, which is the downstream substrate/target of the Lats1/2 kinases. Interestingly, we found that KIBRA stabilizes Lats2 by inhibiting the ubiquitylation of Lats2. KIBRA prolongs the half-life of Lats2. KIBRA itself is a transcriptional target of the Hippo signaling pathway both in mouse and human cells. KIBRA promotes phosphorylation of S83 on Lats2, which is dependent on Aur-A kinase. Over-expression of KIBRA strongly stimulates Aur-A kinase activity revealed by Aur-A auto-phosphorylation level (p-T288). Furthermore, we were able to detect the interaction between Aur-A and KIBRA when these two proteins were co-transfected in 293T cells. We found that KIBRA is a phospho-protein, the phospho-level of KIBRA peaks at the G2/M phase. RNAi-knockdown of KIBRA disrupts the microtubule structure and affects the Aurora-A and Lats2 localization. KIBRA also controls centrosome maturation and chromosome alignment.

该子项目是利用资源的众多研究子项目之一 由 NIH/NCRR 资助的中心拨款提供。子项目的主要支持 并且子项目的主要研究者可能是由其他来源提供的， 包括其他 NIH 来源。 子项目可能列出的总成本 代表子项目使用的中心基础设施的估计数量， NCRR 赠款不直接向子项目或子项目工作人员提供资金。 KIBRA 是果蝇 Hippo 信号通路的一个新组成部分。 KIBRA 影响 Hippo 信号传导的机制以及 KIBRA 在哺乳动物细胞中的功能尚不清楚。 我们证明了 KIBRA 与 Lats1 和 Lats2 关联并激活。此外，我们还发现，KIBRA 特异性 RNAi 的转染会减少，而 KIBRA 的过度表达会增加磷酸化 YAP 的细胞水平，而磷酸化 YAP 是 Lats1/2 激酶的下游底物/靶标。有趣的是，我们发现KIBRA通过抑制Lats2的泛素化来稳定Lats2。 KIBRA 延长 Lats2 的半衰期。 KIBRA 本身是小鼠和人类细胞中 Hippo 信号通路的转录靶标。 KIBRA 促进 Lats2 上 ​​S83 的磷酸化，这依赖于 Aur-A 激酶。 Aur-A 自磷酸化水平 (p-T288) 显示 KIBRA 的过度表达会强烈刺激 Aur-A 激酶活性。此外，当 Aur-A 和 KIBRA 两种蛋白共转染 293T 细胞时，我们能够检测到这两种蛋白之间的相互作用。我们发现KIBRA是一种磷酸化蛋白，KIBRA的磷酸化水平在G2/M期达到峰值。 KIBRA 的 RNAi 敲低会破坏微管结构并影响 Aurora-A 和 Lats2 定位。 KIBRA 还控制中心体成熟和染色体排列。