National Heart and Lung Institute, Imperial College London, London, United Kingdom.
Matrix Biol. 2011 Jan;30(1):16-26. doi: 10.1016/j.matbio.2010.10.004. Epub 2010 Oct 28.
The discoidin domain receptors, DDR1 and DDR2 are cell surface receptor tyrosine kinases that are activated by triple-helical collagen. While normal DDR signalling regulates fundamental cellular processes, aberrant DDR signalling is associated with several human diseases. We previously identified GVMGFO (O is hydroxyproline) as a major DDR2 binding site in collagens I-III, and located two additional DDR2 binding sites in collagen II. Here we extend these studies to the homologous DDR1 and the identification of DDR binding sites on collagen III. Using sets of overlapping triple-helical peptides, the Collagen II and Collagen III Toolkits, we located several DDR2 binding sites on both collagens. The interaction of DDR1 with Toolkit peptides was more restricted, with DDR1 mainly binding to peptides containing the GVMGFO motif. Triple-helical peptides containing the GVMGFO motif induced DDR1 transmembrane signalling, and DDR1 binding and receptor activation occurred with the same amino acid requirements as previously defined for DDR2. While both DDRs exhibit the same specificity for binding the GVMGFO motif, which is present only in fibrillar collagens, the two receptors display distinct preferences for certain non-fibrillar collagens, with the basement membrane collagen IV being exclusively recognised by DDR1. Based on our recent crystal structure of a DDR2-collagen complex, we designed mutations to identify the molecular determinants for DDR1 binding to collagen IV. By replacing five amino acids in DDR2 with the corresponding DDR1 residues we were able to create a DDR2 construct that could function as a collagen IV receptor.
盘状结构域受体 1（DDR1）和盘状结构域受体 2（DDR2）是细胞表面受体酪氨酸激酶，可被三螺旋胶原激活。虽然正常的 DDR 信号调节基本的细胞过程，但异常的 DDR 信号与几种人类疾病有关。我们之前确定 GVMGFO（O 是羟脯氨酸）是 I 型-III 型胶原中 DDR2 的主要结合位点，并在 II 型胶原中发现了另外两个 DDR2 结合位点。在这里，我们将这些研究扩展到同源 DDR1 并确定 III 型胶原上的 DDR 结合位点。使用重叠三螺旋肽套件，即胶原 II 和胶原 III 工具包，我们在两种胶原上定位了几个 DDR2 结合位点。DDR1 与工具包肽的相互作用更为受限，DDR1 主要与含有 GVMGFO 基序的肽结合。含有 GVMGFO 基序的三螺旋肽诱导 DDR1 跨膜信号转导，DDR1 结合和受体激活与先前为 DDR2 定义的相同氨基酸要求发生。虽然两种 DDR 都表现出对结合 GVMGFO 基序的相同特异性，该基序仅存在于纤维胶原中，但两种受体对某些非纤维胶原表现出明显的偏好，基底膜胶原 IV 仅被 DDR1 识别。基于我们最近的 DDR2-胶原复合物晶体结构，我们设计了突变来确定 DDR1 与胶原 IV 结合的分子决定因素。通过用相应的 DDR1 残基替换 DDR2 中的五个氨基酸，我们能够创建一个可以作为胶原 IV 受体发挥作用的 DDR2 构建体。
