Heparin-fibronectin interactions in the development of extracellular matrix insolubility
Heparin-fibronectin interactions in the development of extracellular matrix insolubility
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DOI：
10.1016/j.matbio.2017.11.012
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发表时间：
2018-04-01
期刊：
影响因子：
6.9
通讯作者：
Schwarzbauer, Jean E.
中科院分区：
文献类型：
--
作者：
Reitman, Irene;Huang, Mia L.;Schwarzbauer, Jean E.
在细胞外基质（ECM）组装过程中，纤连蛋白（FN）原纤维不可逆地转化为洗涤剂不溶性形式，其通过FN的多结构域结构可以与胶原、基质细胞蛋白和生长因子相互作用以构建确定的基质。FN还具有肝素/硫酸乙酰肝素（HS）结合位点。使用HS缺陷的CHO细胞，我们表明，除了可溶性肝素显着增加FN矩阵的量，这些细胞组装。硫酸化HS糖胺聚糖（GAG）模拟物同样增加FN组装，并表现出对GAG硫酸化的依赖性。肝素链的长度也在组装中起作用。链的长度足以结合到两个FN分子给最大的刺激组装，而较短的肝素的影响较小。使用脱细胞的成纤维细胞基质的蛋白水解，洗涤剂分馏，和质谱，我们发现，不溶性原纤维片段内的主要结构域是FN的主要肝素结合域HepII（模块III 12 -14）。在尺寸排阻色谱分析中，多个HepII结构域同时与单个肝素链结合。我们提出了一个模型，其中肝素/HS结合到HepII结构域连接多个FN在一起，以促进形成蛋白质相互作用的不溶性原纤维组装。(C)2017爱思唯尔B. V.保留所有权利。
During extracellular matrix (ECM) assembly, fibronectin (FN) fibrils are irreversibly converted into a detergent insoluble form which, through FN's multi-domain structure, can interact with collagens, matricellular proteins, and growth factors to build a definitive matrix. FN also has heparin/heparan sulfate (HS) binding sites. Using HS-deficient CHO cells, we show that the addition of soluble heparin significantly increased the amount of FN matrix that these cells assemble. Sulfated HS glycosaminoglycan (GAG) mimetics similarly increased FN assembly and demonstrated a dependence on GAG sulfation. The length of the heparin chains also plays a role in assembly. Chains of sufficient length to bind to two FN molecules gave maximal stimulation of assembly whereas shorter heparin had less of an effect. Using a decellularized fibroblast matrix for proteolysis, detergent fractionation, and mass spectrometry, we found that the predominant domain within insoluble fibril fragments is FN's major heparin-binding domain HepII (modules III12-14). Multiple HepII domains bind simultaneously to a single heparin chain in size exclusion chromatography analyses. We propose a model in which heparin/HS binding to the HepII domain connects multiple FNs together to facilitate the formation of protein interactions for insoluble fibril assembly. (C) 2017 Elsevier B.V. All rights reserved.