Division of Molecular Pathology, The Institute of Cancer Research, London, United Kingdom.
Proteomics Core Facility, The Institute of Cancer Research, London, United Kingdom.
Biochem Biophys Res Commun. 2018 Jun 18;501(1):124-130. doi: 10.1016/j.bbrc.2018.04.191. Epub 2018 May 3.
Discoidin Domain Receptor 2 (DDR2) is a collagen-binding receptor tyrosine kinase that initiates delayed and sustained tyrosine phosphorylation signalling. To understand the molecular basis of this unique phosphorylation profile, here we utilise fluorescence microscopy to map the spatiotemporal localisation of DDR2 and tyrosine phosphorylated proteins upon stimulation with collagen. We show that cellular phosphorylated proteins are localised to the interface where DDR2 is in contact with collagen and not in the early endosomes or lysosomes. We find that DDR2 localisation is independent of integrin activation and the key DDR2 signalling effector SHC1. Structure-function analysis reveals that DDR2 mutants defective for collagen binding or kinase activity are unable to localise to the cell surface, demonstrating for the first time that both collagen binding and kinase functions are required for spatial localisation of DDR2. This study provides new insights into the underlying structural features that control DDR2 activation in space and time.
Discoidin Domain Receptor 2 (DDR2) 是一种胶原结合受体酪氨酸激酶，可启动延迟和持续的酪氨酸磷酸化信号转导。为了了解这种独特的磷酸化谱的分子基础，我们利用荧光显微镜来描绘 DDR2 和酪氨酸磷酸化蛋白在与胶原刺激时的时空定位。我们表明，细胞内磷酸化蛋白定位于 DDR2 与胶原接触的界面，而不是早期内体或溶酶体。我们发现 DDR2 的定位与整联蛋白的激活和关键的 DDR2 信号效应因子 SHC1 无关。结构功能分析表明，胶原结合或激酶活性缺陷的 DDR2 突变体不能定位于细胞表面，这首次表明胶原结合和激酶功能对于 DDR2 的空间定位都是必需的。本研究为控制 DDR2 在空间和时间激活的基础结构特征提供了新的见解。
