MDM2 influences ACE2 stability and SARS-Cov2 uptake

The Angiotensin-converting enzyme 2 (ACE2) receptor is the central entry point for SARS-Cov2. Several SAR-Cov2 substrains have developed mutations in their spike protein to maximize their use of ACE2, e.g. to strengthen ACE2 binding for increased uptake or adapt to specific amino acid properties of ACE2 to cross the species barrier. But little is known about the effect of host regulators on ACE2 and subsequently their impact on SARS-Cov2 infection. Here we identify the E3 ligase MDM2 as a ACE2 modulator. The knockout of MDM2 induced a strong pro-viral effect specific for SARS-Cov2 and we could see the increase of ACE2 levels. This effect is likely dependent on the ubiquitination site Lysine 788, which MDM2 uses to induce proteasomal degradation of ACE2. Substituting this amino acid led to increased ACE2 levels and increased SARS-CoV2 infection facilitated by enhanced SARS-Cov2 uptake.