Protein kinase C ∈ stabilizes β-catenin and regulates its subcellular localization in podocytes
Protein kinase C ∈ stabilizes β-catenin and regulates its subcellular localization in podocytes
复制标题
DOI：
10.1074/jbc.m117.775700
复制
发表时间：
2017-07-21
影响因子：
4.8
通讯作者：
Schiffer, Mario
中科院分区：
文献类型：
--
作者：
Duong, Michelle;Yu, Xuejiao;Schiffer, Mario
肾脏疾病与肾细胞如足细胞中通过PKC的信号转导失调有关。PKC α是PKC的常规同种型，并且是众所周知的促进其降解的β-连环蛋白的结合配偶体。β-连环蛋白是经典Wnt途径的主要效应物，在细胞粘附中至关重要。然而，其他PKC亚型是否与β-连环蛋白相互作用尚未系统研究。在这里，我们证明，PKC是一个元素的缺陷小鼠，其中发展蛋白尿和肾小球硬化症，显示较低的β-连环蛋白表达与PKC野生型小鼠相比，符合改变足细胞在文化中的表型。值得注意的是，β-连环蛋白显示出相反的亚细胞定位模式：尽管β-连环蛋白在未分化的野生型细胞中表现出核周模式，但它主要定位于PKC中的细胞核，PKC是敲除细胞的一个元素。两种细胞类型的佛波醇12-肉豆蔻酸酯13-乙酸酯刺激揭示了PKC是以糖原合成酶激酶3 β-非依赖性方式正向调节β-连环蛋白表达和稳定的元件。此外，β-连环蛋白在PKC中的过表达是缺陷足细胞可以恢复野生型表型的一个要素，类似于用PKC进行拯救是构建的一个要素。这种作用是通过上调P-钙粘蛋白和β-连环蛋白下游靶fascin 1介导的。斑马鱼研究表明，三个PKC是β-连环蛋白中的特异性磷酸化位点的元件，其是完整的β-连环蛋白功能所必需的。免疫共沉淀和pulldown试验证实PKC是和β-连环蛋白作为结合伴侣的一个元素，并揭示了三个PKC是磷酸化位点的一个元素的消融减弱了它们的相互作用。总之，我们确定了一种新的β-连环蛋白水平调节途径，并定义PKC是一种重要的β-连环蛋白相互作用伙伴和其他PKC亚型在足细胞中的信号对手。
Kidney disease has been linked to dysregulated signaling via PKC in kidney cells such as podocytes. PKC alpha is a conventional isoform of PKC and a well-known binding partner of beta-catenin, which promotes its degradation. beta-Catenin is the main effector of the canonical Wnt pathway and is critical in cell adhesion. However, whether other PKC isoforms interact with beta-catenin has not been studied systematically. Here we demonstrate that PKC is an element of-deficient mice, which develop proteinuria and glomerulosclerosis, display lower beta-catenin expression compared with PKC wild-type mice, consistent with an altered phenotype of podocytes in culture. Remarkably, beta-catenin showed a reversed subcellular localization pattern: Although beta-catenin exhibited a perinuclear pattern in undifferentiated wild-type cells, it predominantly localized to the nucleus in PKC is an element of knockout cells. Phorbol 12-myristate 13-acetate stimulation of both cell types revealed that PKC is an element of positively regulates beta-catenin expression and stabilization in a glycogen synthase kinase 3 beta-independent manner. Further, beta-catenin overexpression in PKC is an element of-deficient podocytes could restore the wild-type phenotype, similar to rescue with a PKC is an element of construct. This effect was mediated by up-regulation of P-cadherin and the beta-catenin downstream target fascin1. Zebrafish studies indicated three PKC is an element of-specific phosphorylation sites in beta-catenin that are required for full beta-catenin function. Co-immunoprecipitation and pulldown assays confirmed PKC is an element of and beta-catenin as binding partners and revealed that ablation of the three PKC is an element of phosphorylation sites weakens their interaction. In summary, we identified a novel pathway for regulation of beta-catenin levels and definePKC is an element of as an important beta-catenin interaction partner and signaling opponent of other PKC isoforms in podocytes.