Collagen XVI harbors an integrin α1β1 recognition site in its C-terminal domains
Collagen XVI harbors an integrin α1β1 recognition site in its C-terminal domains
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DOI：
10.1074/jbc.m509942200
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发表时间：
2006-09-01
影响因子：
4.8
通讯作者：
Graessel, Susanne
中科院分区：
文献类型：
--
作者：
Eble, Johannes A.;Kassner, Anja;Graessel, Susanne
胶原蛋白XVI以组织依赖性方式整合成不同的纤维状聚集体，例如D带软骨原纤维和含软骨素-1的微纤维。在皮肤中，胶原XVI的分布与胶原结合整合素α 1 β 1和α 2 β 1的分布重叠。基底层角质形成细胞表达整合素α 2 β 1，而整合素α 1 β 1存在于血管周围的平滑肌细胞、毛囊和脂肪细胞中。携带整合素α 1 β 1和α 2 β 1的细胞在重组胶原蛋白XVI上附着并扩散。此外，胶原蛋白XVI诱导这些整合素募集到粘着斑中，这是整合素信号传导的主要步骤。潜在的生理相关性，这些整合素-胶原蛋白XVI相互作用可以连接细胞与专门的纤维，从而有助于结缔组织内的纤维和细胞成分的组织。在无细胞结合试验中，胶原XVI与α 1 β 1整联蛋白的结合比与α 2 β 1整联蛋白的结合更强烈。两种整合素通过其α亚基的A结构域与胶原XVI相互作用。包含胶原结构域1 - 3的胰蛋白酶胶原XVI片段被α 1 β 1整联蛋白识别。α 1 β 1整联蛋白与胰蛋白酶胶原蛋白XVI片段或全长胶原蛋白XVI的复合物的电子显微镜显示胶原蛋白XVI内靠近其C末端的独特α 1 β 1整联蛋白结合位点。
Collagen XVI is integrated tissue-dependently into distinct fibrillar aggregates, such as D-banded cartilage fibrils and fibrillin-1-containing microfibrils. In skin, the distribution of collagen XVI overlaps that of the collagen-binding integrins alpha 1 beta 1 and alpha 2 beta 1. Basal layer keratinocytes express integrin alpha 2 beta 1, whereas integrin alpha 1 beta 1 occurs in smooth muscle cells surrounding blood vessels, in hair follicles, and on adipocytes. Cells bearing the integrins alpha 1 beta 1 and alpha 2 beta 1 attach and spread on recombinant collagen XVI. Furthermore, collagen XVI induces the recruitment of these integrins into focal adhesion plaques, a principal step in integrin signaling. Of potential physiological relevance, these integrin-collagen XVI interactions may connect cells with specialized fibrils, thus contributing to the organization of fibrillar and cellular components within connective tissues. In cell-free binding assays, collagen XVI is more avidly bound by alpha 1 beta 1 integrin than by alpha 2 beta 1 integrin. Both integrins interact with collagen XVI via the A domain of their alpha subunits. A tryptic collagen XVI fragment comprising the collagenous domains 1 - 3 is recognized by alpha 1 beta 1 integrin. Electron microscopy of complexes of alpha 1 beta 1 integrin with this tryptic collagen XVI fragment or with full-length collagen XVI revealed a unique alpha 1 beta 1 integrin-binding site within collagen XVI located close to its C-terminal end.