Bartolomé Alberto, Liang Jiani, Wang Pengfei, Ho David D, Pajvani Utpal B
bioRxiv. 2020 Sep 1:2020.09.01.277954. doi: 10.1101/2020.09.01.277954.
Angiotensin converting enzyme 2 (ACE2) is a key regulator of the renin-angiotensin system, but also the functional receptor of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Based on structural similarity with other γ-secretase (γS) targets, we hypothesized that ACE2 may be affected by γS proteolytic activity. We found that after ectodomain shedding, ACE2 is targeted for intramembrane proteolysis by γS, releasing a soluble ACE2 C-terminal fragment. Consistently, chemical or genetic inhibition of γS results in the accumulation of a membrane-bound fragment of ectodomain-deficient ACE2. Although chemical inhibition of γS does not alter SARS-CoV-2 cell entry, these data point to a novel pathway for cellular ACE2 trafficking.
血管紧张素转换酶2(ACE2)是肾素-血管紧张素系统的关键调节因子,也是严重急性呼吸综合征冠状病毒2(SARS-CoV-2)的功能性受体。基于与其他γ-分泌酶(γS)靶点的结构相似性,我们推测ACE2可能受γS蛋白水解活性的影响。我们发现,在胞外域脱落之后,ACE2会被γS靶向进行膜内蛋白水解,释放出可溶性的ACE2 C末端片段。一致地,γS的化学或基因抑制导致胞外域缺陷型ACE2的膜结合片段积累。尽管γS的化学抑制不会改变SARS-CoV-2的细胞进入,但这些数据指向了细胞ACE2转运的一条新途径。