SUMOylation restrains ACE2 degradation through TOLLIP-mediated selective autophagy to facilitate the host susceptibility to SARS-CoV-2 infection

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the ongoing coronavirus disease 2019 (COVID-19) pandemic. Alongside investigations into the virology of SARS-CoV-2, understanding the host–virus dependencies are vital for the identification and rational design of effective antiviral therapy. Here, we report the dominant SARS-CoV-2 entry receptor, ACE2, conjugates with small ubiquitin-like modifier 3 (SUMO3) through a proteome-wide protein interaction analysis. We further demonstrate that E3 SUMO ligase PIAS4 prompts the SUMOylation and stabilization of ACE2, whereas deSUMOylation enzyme SENP3 reverses this process. Conjugation of SUMO3 with ACE2 at lysine (K) 187 hampers the K48-linked ubiquitination of ACE2, thus suppressing its subsequent cargo receptor TOLLIP-dependent autophagic degradation. Pharmacological intervention of ACE2 SUMOylation blocks the entry of SARS-CoV-2 and viral infection-triggered immune responses. Collectively, our findings suggest selective autophagic degradation of ACE2 orchestrated by SUMOylation and ubiquitination can be targeted to future antiviral therapy of SARS-CoV-2.