Tumor necrosis factor-alpha convertase (ADAM17) mediates regulated ectodomain shedding of the severe-acute respiratory syndrome-coronavirus (SARS-CoV) receptor, angiotensin-converting enzyme-2 (ACE2).
Tumor necrosis factor-alpha convertase (ADAM17) mediates regulated ectodomain shedding of the severe-acute respiratory syndrome-coronavirus (SARS-CoV) receptor, angiotensin-converting enzyme-2 (ACE2).
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DOI：
10.1074/jbc.m505111200
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发表时间：
2005-08-26
期刊：
影响因子：
--
通讯作者：
Turner AJ
中科院分区：
文献类型：
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作者：
Lambert DW;Yarski M;Warner FJ;Thornhill P;Parkin ET;Smith AI;Hooper NM;Turner AJ
血管紧张素转换酶-2 （ACE2）是心脏功能的关键调节剂，也是严重急性呼吸综合征（SARS）， SARS- cov（冠状病毒）病原体的细胞受体。ACE2是一种I型跨膜蛋白，胞外n端结构域含有活性位点，胞内c端短尾。ACE2的可溶性形式缺乏胞质和跨膜结构域，已被证明可以阻止sars冠状病毒刺突蛋白与其受体的结合。在这项研究中，我们检测了ACE2进行蛋白水解脱落的能力，并研究了这种脱落事件的机制。我们证明ACE2在HEK293细胞中异种表达，在Huh7细胞中内源性表达，经历金属蛋白酶介导的，磷酯诱导的外畴脱落。通过对adisintegrin和metalloproteinase家族蛋白酶的不同成员使用不同效价的抑制剂，我们确定ADAM17是刺激ACE2脱落的候选介质。此外，使用特异性小干扰RNA双链去除ADAM17表达可减少受调节的ACE2脱落，而过表达ADAM17可显著增加脱落。综上所述，这些数据为ADAM17参与ACE2调控的外结构域脱落提供了直接证据。ADAM17作为负责ACE2脱落的蛋白酶的鉴定可能为ACE2的生理作用提供新的见解。
Angiotensin-converting enzyme-2 (ACE2) is a critical regulator of heart function and a cellular receptor for the causative agent of severe-acute respiratory syndrome (SARS), SARS-CoV (coronavirus). ACE2 is a type I transmembrane protein, with an extracellular N-terminal domain containing the active site and a short intracellular C-terminal tail. A soluble form of ACE2, lacking its cytosolic and transmembrane domains, has been shown to block binding of the SARS-CoV spike protein to its receptor. In this study, we examined the ability of ACE2 to undergo proteolytic shedding and investigated the mechanisms responsible for this shedding event. We demonstrated that ACE2, heterologously expressed in HEK293 cells and endogenously expressed in Huh7 cells, undergoes metalloproteinase-mediated, phorbol ester-inducible ectodomain shedding. By using inhibitors with differing potency toward different members of the ADAM (adisintegrin and metalloproteinase) family of proteases, we identified ADAM17 as a candidate mediator of stimulated ACE2 shedding. Furthermore, ablation of ADAM17 expression using specific small interfering RNA duplexes reduced regulated ACE2 shedding, whereas overexpression of ADAM17 significantly increased shedding. Taken together, these data provided direct evidence for the involvement of ADAM17 in the regulated ectodomain shedding of ACE2. The identification of ADAM17 as the protease responsible for ACE2 shedding may provide new insight into the physiological roles of ACE2.