Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, UMR 144, Paris, France.
Cell and Tissue Imaging Facility (PICT-IBiSA), Institut Curie, PSL Research University, Centre National de la Recherche Scientifique, Paris, France.
J Cell Biol. 2020 Sep 7;219(9). doi: 10.1083/jcb.201910132.
Tumor cells exposed to a physiological matrix of type I collagen fibers form elongated collagenolytic invadopodia, which differ from dotty-like invadopodia forming on the gelatin substratum model. The related scaffold proteins, TKS5 and TKS4, are key components of the mechanism of invadopodia assembly. The molecular events through which TKS proteins direct collagenolytic invadopodia formation are poorly defined. Using coimmunoprecipitation experiments, identification of bound proteins by mass spectrometry, and in vitro pull-down experiments, we found an interaction between TKS5 and FGD1, a guanine nucleotide exchange factor for the Rho-GTPase CDC42, which is known for its role in the assembly of invadopodial actin core structure. A novel cell polarity network is uncovered comprising TKS5, FGD1, and CDC42, directing invadopodia formation and the polarization of MT1-MMP recycling compartments, required for invadopodia activity and invasion in a 3D collagen matrix. Additionally, our data unveil distinct signaling pathways involved in collagenolytic invadopodia formation downstream of TKS4 or TKS5 in breast cancer cells.
肿瘤细胞暴露在 I 型胶原纤维的生理基质中会形成拉长的胶原降解侵袭伪足，这与在明胶基底模型上形成的点状侵袭伪足不同。相关支架蛋白 TKS5 和 TKS4 是侵袭伪足组装机制的关键组成部分。TKS 蛋白指导胶原降解侵袭伪足形成的分子事件还未完全定义。通过共免疫沉淀实验、质谱鉴定结合蛋白、体外下拉实验，我们发现 TKS5 与 FGD1 之间存在相互作用，FGD1 是 Rho-GTPase CDC42 的鸟嘌呤核苷酸交换因子，CDC42 已知在侵袭伪足肌动蛋白核心结构的组装中起作用。一个新的细胞极性网络被揭示，包含 TKS5、FGD1 和 CDC42，指导侵袭伪足的形成和 MT1-MMP 回收隔室的极化，这对于侵袭伪足在 3D 胶原基质中的活性和侵袭是必需的。此外，我们的数据揭示了在乳腺癌细胞中 TKS4 或 TKS5 下游参与胶原降解侵袭伪足形成的不同信号通路。
