Casein Kinase 1 Delta in Wnt Signaling and Beyond

Wnt 信号传导及其他领域的酪蛋白激酶 1 Delta

• 批准号: 8763413
• 负责人: Jeffrey Rubin
• 金额: $ 44.53万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8763413
• 关键词: AKAP9 gene; Accounting; Alanine; Amino Acids; Binding; Binding Sites; CSNK1A1 gene; Cell Cycle Progression; Cell Polarity; Cells; Centrosome; Cilia; Defect; Disease; Embryo; Embryonic Development; Ewings sarcoma; Exhibits; Fibroblasts; Golgi Apparatus; Knockout Mice; Maintenance; Mediating; Microtubules; Mus; Neural Tube Defects; Neurites; PKD2 protein; Pathogenesis; Phosphorylation; Phosphorylation Site; Polycystic Kidney Diseases; Process; Proteins; Regulation; Retinal; Role; Signal Transduction; Site; Situs Inversus; Work; casein kinase I; cell motility; cilium biogenesis; insight; neoplastic cell; overexpression; response

We established that cells from Ewing tumors form neurites in response to Wnt-3a and have begun to define the mechanisms that account for this effect. Knockdown of the atypical PKCiota also blocked Wnt-3a-dependent neurite outgrowth. Wnt-3a stimulated the phosphorylation of PKCi. Dvl2 co-immunoprecipitated with PKCi, and this interaction did not occur when CK1 phosphorylation sites in Dvl2 were replaced with alanine residues. These results suggested that Dvl2 phosphorylation by CK1 was required for Dvl2-PKCi binding, which in turn might be necessary for neurite outgrowth. This work is significant not only because it provides insights about mechanisms involved in the formation of neurites. Many of the factors that participate in neurite outgrowth contribute to cell polarity in other contexts such as the formation of cellular extensions critical for cell migration. Inhibition of CK1d blocked primary ciliogenesis in hTERT-RPE and mIMCD3 cells. Mouse embryonic fibroblasts and retinal cells from CK1d null mice also exhibited ciliogenesis defects. Interference with CK1d expression or catalytic activity disrupted the pericentrosomal or ciliary distribution of several proteins involved in ciliary transport, including Rab11a, Rab8a, CEP290, PCM1 and polycystin-2, as well as the Golgi distribution of AKAP450. Similar to its binding partner AKAP450, CK1d was required for microtubule nucleation at the Golgi and maintenance of Golgi integrity. Overexpression of an AKAP450 fragment containing the CK1d binding site inhibited Golgi-derived microtubule nucleation, Golgi distribution of IFT20 and ciliogenesis. Our results suggest that CK1d mediates primary ciliogenesis by coordinating the distribution and presumably function of multiple factors at or near the centrosome and Golgi to promote ciliary transport. Defective primary cilia are responsible for several disorders including neural tube defects, polycystic kidney disease and situs inversus. Aberrant Wnt signaling also can elicit these abnormalities. Thus, our studies of CK1d and Dvl may provide new insight about the ways in which Wnt signaling controls embryonic development and its dysregulation contributes to pathogenesis.

我们建立了尤文肿瘤细胞对WNT-3a的反应形成神经突起，并开始定义解释这一效应的机制。敲除非典型的PKCiota也阻止了Wnt-3a依赖的神经突起的生长。WNT-3a可刺激PKCi的磷酸化。Dvl2与PKCi共沉淀，当Dvl2中的CK1磷酸化位点被丙氨酸残基取代时，这种相互作用不发生。这些结果提示，Dvl2与PKCi的结合需要CK1对Dvl2的磷酸化，这可能是轴突生长所必需的。这项工作意义重大，不仅是因为它提供了对神经突起形成机制的洞察。许多参与轴突生长的因素在其他环境中对细胞极性有贡献，例如对细胞迁移至关重要的细胞延伸的形成。抑制CK1d可阻断hTERT-RPE和mIMCD3细胞的原发纤毛发生。CK1d基因缺失小鼠的小鼠胚胎成纤维细胞和视网膜细胞也显示出纤毛发生缺陷。干扰CK1d的表达或催化活性会干扰几种参与纤毛运输的蛋白质，包括Rab11a、Rab8a、CEP290、PCM1和Polycystin-2的分布，以及AKAP450的高尔基分布。与其结合伙伴AKAP450类似，CK1d也是高尔基体微管成核和维持高尔基体完整性所必需的。含有CK1d结合位点的AKAP450片段的过表达抑制了高尔基体来源的微管成核、IFT20的高尔基体分布和纤毛发生。我们的结果表明，CK1d通过协调中心体和高尔基体处或附近促进纤毛运输的多种因素的分布和可能的作用来介导原发纤毛的发生。初级纤毛缺陷是几种疾病的原因，包括神经管缺陷、多囊肾病和内翻。Wnt信号的异常也可以引起这些异常。因此，我们对CK1d和DVL的研究可能为Wnt信号控制胚胎发育及其失调在发病机制中的作用提供新的见解。