Functional classification of ADAMs based on a conserved motif for binding to integrin α9β1 -: Implications for sperm-egg binding and other cell interactions
Functional classification of ADAMs based on a conserved motif for binding to integrin α9β1 -: Implications for sperm-egg binding and other cell interactions
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DOI：
10.1074/jbc.m200086200
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发表时间：
2002-05-17
影响因子：
4.8
通讯作者：
Takada, Y
中科院分区：
文献类型：
--
作者：
Eto, K;Huet, C;Takada, Y
亚当斯（一种去整合素和金属蛋白酶）是金属蛋白酶的metzincin超家族的成员。在与亚当斯的去整合素结构域结合的整合素中，有α（9）β（1）和α（v）β（3），它们分别以RGD非依赖性和RGD依赖性方式结合。人ADAM 15是唯一在去整合素结构域中具有RGD基序的ADAM。因此，整合素α（9）β（1）和α（v）β（3）都识别ADAM 15去整合素结构域。我们通过突变分析确定了这些整合素如何识别ADAM 15去整合素结构域。我们发现Arg（481）和Asp-Leu-Pro-Glu-Phe残基（残基488-492）对于α（9）β（1）结合是关键的，但RGD基序（残基484-486）不是。相比之下，RGD基序对于α（v）β（3）结合是至关重要的，但RGD基序侧翼的其他残基不是。由于RX 6DLPEF α（9）β（1）识别基序（残基481-492）在除ADAM 10和17外的亚当斯中是保守的，我们假设α（9）β（1）可以识别除ADAM 10和17外的所有亚当斯中的去整合素结构域。事实上，我们发现α（9）β（1）与ADAM 1、2、3和9的去整合素结构域结合强烈，但不与ADAM 10和17的去整合素结构域结合。由于几种亚当斯与精子-卵母细胞相互作用有关，我们测试了基于整合素α（9）β（1）特异性的亚当斯功能分类是否适用于精卵结合。我们发现ADAM 2和15去整合素结构域与卵母细胞结合，而ADAM 17去整合素结构域不与卵母细胞结合。此外，ADAM 2和15去整合素结构域有效地阻止精子与卵母细胞的结合，但ADAM 17去整合素结构域没有。这些结果表明，卵母细胞和α（9）β（1）对亚当斯具有相似的结合特异性，α（9）β（1）或具有相似特异性的受体可能参与受精过程中的精卵相互作用。由于α（9）β（1）是许多ADAM去整合素的受体，并且α（9）β（1）和亚当斯广泛表达，因此α（9）β（1）-ADAM相互作用可能具有广泛的生物学重要性。
ADAMs (a disintegrin and metalloproteases) are members of the metzincin superfamily of metalloproteases. Among integrins binding to disintegrin domains of ADAMs are alpha(9)beta(1) and alpha(v)beta(3), and they bind in an RGD-independent and an RGD-dependent manner, respectively. Human ADAM15 is the only ADAM with the RGD motif in the disintegrin domain. Thus, both integrin alpha(9)beta(1) and alpha(v)beta(3) recognize the ADAM15 disintegrin domain. We determined how these integrins recognize the ADAM15 disintegrin domain by mutational analysis. We found that the Arg(481) and the Asp-Leu-Pro-Glu-Phe residues (residues 488-492) were critical for alpha(9)beta(1) binding, but the RGD motif (residues 484-486) was not. In contrast, the RGD motif was critical for alpha(v)beta(3) binding, but the other residues flanking the RGD motif were not. As the RX6DLPEF alpha(9)beta(1) recognition motif (residues 481-492) is conserved among ADAMs, except for ADAM10 and 17 we hypothesized that alpha(9)beta(1) may recognize disintegrin domains in all ADAMs except ADAM10 and 17. Indeed we found that alpha(9)beta(1) bound avidly to the disintegrin domains of ADAM1, 2, 3, and 9 but not to the disintegrin domains of ADAM10 and 17. As several ADAMs have been implicated in sperm-oocyte interaction, we tested whether the functional classification of ADAMs, based on specificity for integrin alpha(9)beta(1), applies to sperm-egg binding. We found that the ADAM2 and 15 disintegrin domains bound to oocytes, but the ADAM17 disintegrin domain did not. Furthermore, the ADAM2 and 15 disintegrin domains effectively blocked binding of sperm to oocytes, but the ADAM17 disintegrin domain did not. These results suggest that oocytes and alpha(9)beta(1) have similar binding specificities for ADAMs and that alpha(9)beta(1), or a receptor with similar specificity, may be involved in sperm-egg interaction during fertilization. As alpha(9)beta(1) is a receptor for many ADAM disintegrins and alpha(9)beta(1) and ADAMs are widely expressed, alpha(9)beta(1)-ADAM interaction may be of a broad biological importance.