Pericellular proteolysis by matrix metalloproteinase-7 is differentially modulated by cholesterol sulfate, sulfatide, and cardiolipin.
Pericellular proteolysis by matrix metalloproteinase-7 is differentially modulated by cholesterol sulfate, sulfatide, and cardiolipin.
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基质金属蛋白酶 7 的细胞周蛋白水解受到硫酸胆固醇、脑硫脂和心磷脂的差异调节。
DOI：
10.1111/febs.12865
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
and Shouichi Higashi
中科院分区：
文献类型：
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作者：
Kazuhiro Yamamoto;Kaoru Miyazaki;and Shouichi Higashi
基质金属蛋白酶(MMP7)与细胞表面的硫酸胆固醇(CS)结合，是一种膜相关的蛋白酶。我们先前已经发现，CS调节基质金属蛋白酶-7的底物偏好，从而调节其细胞周围的蛋白降解作用。当基质金属蛋白酶-7在细胞表面过表达时，它们可能通过硫脂(SM4)和心磷脂(CL)与细胞表面结合。在这里，我们研究了这些酸性脂类与基质金属蛋白酶-7或其底物之间的分子相互作用，以及它们对基质金属蛋白酶-7活性的影响。使用低CS结合能力的基质金属蛋白酶-7变异体的研究表明，这些脂类与基质金属基质-7上的相似部位相互作用。基于羟基甲酸酯的基质金属蛋白酶抑制剂TAPI-1显著降低了基质金属蛋白酶-7对CS和CL的亲和力，而对SM4的亲和力不受TAPI-1的影响。这三种酸性脂类对基质金属蛋白酶-7对小肽底物的水解活性也有不同的影响：SM4、CL和CS使活性分别降低到80%、92%和20%。分别进行了分析。然而，SM4和CS类似地加速了基质金属蛋白酶-7催化的纤维连接蛋白和层粘连蛋白-332的降解，而CL不能。只有当底物和酶都与脂质有亲和力时，才能观察到底物蛋白分解的增加，这表明脂类可能使反应物更接近。此外，与细胞表面SM4或CS结合的MMP7可切割特定的细胞表面蛋白并释放类似的片段，而细胞表面CL结合的MMP7不能刺激这种切割。本研究提供了一种新的机制，即酸性脂类通过改变底物结合部位及其与基质的内在亲和力来差异化地调节MMP7对细胞周蛋白的降解。
Matrix metalloproteinase (MMP)‐7 binds to cell surface cholesterol sulfate (CS) and acts as a membrane‐associated protease. We have previously found that CS modulates the substrate preference of MMP‐7, thereby regulating its pericellular proteolytic action. MMP‐7 potentially associates with the cell surface via sulfatide (SM4) and cardiolipin (CL) when they are overexpressed on the cell surface. Here, we investigated the molecular interaction between these acidic lipids and MMP‐7 or its substrates, and their effects on the activity of MMP‐7. Studies using MMP‐7 variants with low CS‐binding ability suggested that these lipids interact with a similar site on MMP‐7. The hydroxamate‐based MMP inhibitor TAPI‐1 markedly reduced the affinity of MMP‐7 for CS and CL, whereas that for SM4 was not affected by TAPI‐1. These three acidic lipids also had different effects on the hydrolytic activity of MMP‐7 towards a small peptide substrate: SM4, CL and CS reduced the activity to 80%, 92%, and 20%, respectively. Nevertheless, SM4 and CS similarly accelerated the MMP‐7‐catalyzed degradation of fibronectin and laminin‐332, whereas CL did not. The increased proteolysis of substrate was observed only when both substrate and enzyme had affinity for the lipid, suggesting that the lipids probably bring the reactants into closer proximity. Furthermore, MMP‐7 bound to cell surface SM4 or CS cleaved specific cell surface proteins and released similar fragments, whereas the cleavage was not stimulated by cell surface CL‐bound MMP‐7. This study provides a novel mechanism by which acidic lipids differentially regulate pericellular proteolysis by MMP‐7 through allosteric alteration of the substrate‐binding site and their inherent affinities for MMP‐7 substrates.