Cell surface annexins regulate ADAM-mediated ectodomain shedding of proamphiregulin.
Cell surface annexins regulate ADAM-mediated ectodomain shedding of proamphiregulin.
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DOI：
10.1091/mbc.e11-08-0683
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发表时间：
2012-05
影响因子：
3.3
通讯作者：
Higashiyama S
中科院分区：
文献类型：
--
作者：
Nakayama H;Fukuda S;Inoue H;Nishida-Fukuda H;Shirakata Y;Hashimoto K;Higashiyama S
表皮生长因子受体（EGFR）及其下游信号网络的反式激活过程中，ADAM17对EGFR配体的胞外区脱落是关键步骤。在这项研究中，我们确定了细胞表面膜联蛋白作为双调蛋白前体胞外区脱落的调节因子。我们建议，细胞表面膜联蛋白作为一个脱落的平台，以确定底物选择性的ADAM 17。去整合素和金属蛋白酶（ADAM）是参与各种膜蛋白的胞外域脱落的酶家族。然而，亚当斯识别的分子机制仍然未知。在这项研究中，我们成功地捕获和分析了细胞表面的跨膜双调蛋白前体（proAREG）和ADAM 17之间的瞬态组件在早期脱落阶段，这使得识别细胞表面膜联蛋白作为其脱落复合物的组成部分。膜联蛋白家族成员膜联蛋白A2（ANXA 2）、A8和A9与细胞表面上的proAREG和ADAM 17相互作用。当ANXA 2被敲低时，proAREG的脱落增加，但随着ANXA 8和A9的敲低而减少，这分别是因为与ADAM 17的关联增强和受损。原代角质形成细胞中ANXA 2和A8的敲低改变了伤口诱导的细胞迁移和紫外线B诱导的表皮生长因子受体（EGFR）磷酸化，表明膜联蛋白在ADAM介导的EGFR配体胞外结构域脱落中发挥重要作用。在这些数据的基础上，我们提出细胞表面的膜联蛋白作为“脱落平台”蛋白来确定ADAM 17的底物选择性，在ADAM相关疾病中具有可能的治疗潜力。
Ectodomain shedding of EGFR ligands by ADAM17 is a key step of transactivation of epidermal growth factor receptor (EGFR) and the downstream signaling network. In this study, we identified cell surface annexins as regulators of ectodomain shedding of amphiregulin precursor. We propose that cell surface annexins act as a shedding platform to determine the substrate selectivity of ADAM17. A disintegrin and metalloproteinase (ADAM) is a family of enzymes involved in ectodomain shedding of various membrane proteins. However, the molecular mechanism underlying substrate recognition by ADAMs remains unknown. In this study, we successfully captured and analyzed cell surface transient assemblies between the transmembrane amphiregulin precursor (proAREG) and ADAM17 during an early shedding phase, which enabled the identification of cell surface annexins as components of their shedding complex. Annexin family members annexin A2 (ANXA2), A8, and A9 interacted with proAREG and ADAM17 on the cell surface. Shedding of proAREG was increased when ANXA2 was knocked down but decreased with ANXA8 and A9 knockdown, because of enhanced and impaired association with ADAM17, respectively. Knockdown of ANXA2 and A8 in primary keratinocytes altered wound-induced cell migration and ultraviolet B–induced phosphorylation of epidermal growth factor receptor (EGFR), suggesting that annexins play an essential role in the ADAM-mediated ectodomain shedding of EGFR ligands. On the basis of these data, we propose that annexins on the cell surface function as “shedding platform” proteins to determine the substrate selectivity of ADAM17, with possible therapeutic potential in ADAM-related diseases.