Multiple independent acquisitions of ACE2 usage in MERS-related coronaviruses

Abstract

The unknown identity of the entry receptors utilized by many coronaviruses has significantly impeded our comprehensive understanding of these important pathogens. We recently reported an unexpected usage of angiotensin-converting enzyme 2 (ACE2), instead of Dipeptidyl peptidase-4 (DPP4), for cellular entry by NeoCoV and PDF-2180, close relatives of MERS-CoV that infect African bats. However, the presence and distribution of other ACE2-using merbecoviruses remain enigmatic. In this study, through sequence and structural analyses, we predicted that two newly discovered merbecoviruses infecting European Pipistrellus bats (Pipistrellus nathusii), namely MOW-15-22 and PnNL2018B, may also utilize ACE2 as their receptors. Functional profiling of 103 ACE2 orthologues from a variety of mammals confirmed that several ACE2 from bats efficiently facilitate the entry of MOW-15-22 and PnNL2018B. Conversely, no binding or entry signals for both viruses were detected when assessing seven DPP4 orthologues from humans, hedgehogs, and bats. Characterization of Pteronotus davyi (P.dav) ACE2 mediated entry of MOW-15-22 reveals a significant exogenous protease dependence, which can be dose-dependently neutralized by soluble P.dav ACE2 recombinant protein and a broadly neutralizing S2-targeting antibody. Verification of the previously reported critical ACE2 determinants forNeoCoV recognition reveals thatMOW-15-22 and PnNL2018B displayed a glycan-independent binding mode with significantly altered interaction details. This study sheds light on two additional ACE2-using merbecoviruses circulating among European bats and underscores the potential zoonotic risk associated with these viruses.

Recombination analysis on the receptor switching event of MERS-CoV and its close relatives: implications for the emergence of MERS-CoV

“…According to the tree topology, we classified merbecoviruses into 9 groups (Fig. 1 ): the MERS-CoV group that is a known human DPP4 (hDPP4)-using virus that infects camels and humans [ 15 ]; the group 1 bat MERS-related CoVs (MCr-CoVs) consisting of NeoCoV and PDF-2180 which were described to use bat ACE2 (bACE2) orthologues, and less efficiently human ACE2 (hACE2) [ 16 ]; the group 2 bat MCr-CoVs that includes the PnNL2018B and MOW15-22 that were recently documented to also use bACE2 [ 17 ]; the group 3 bat MCr-CoVs which includes bat viruses, like BtCoV-422 that can use hDPP4 and bDPP4 [ 46 ], and HKU25 that can use hDPP4 [ 47 ]; the group 4 bat MCr-CoVs that includes PaGB01 that cannot use hACE2, hDPP4 and human aminopeptidase N (hAPN) [ 48 ]; the Tylonycteris HKU4 group that uses hDPP4 and bDPP4 [ 49 , 50 ]; the recently identified pangolin HKU4 that efficiently uses hDPP4, bDPP4, and pangolin DPP4 [ 51 ]; the Pipistrellus HKU5 group that cannot use hACE2, bACE2, hDPP4 or bDPP4 [ 16 , 46 , 49 ], but was recently shown to use Pipistrellus abramus ACE2 (the group’s reservoir bat host) [ 52 ], and lastly, the Hedgehog-CoV-1 group which also cannot use hACE2 or hedgehog ACE2 as its viral receptor [ 16 ]. The latter is the outgroup of the known merbecoviruses based on rooting by the sarbecoviruses (Fig.…”

“…Importantly, although MERS-CoV utilizes dipeptidyl peptidase 4 (DPP4) as the viral receptor [ 15 ], a previous study by Xiong et al (2022) showed that NeoCoV and PDF-2180 utilize angiotensin-converting enzyme 2 (ACE2) as their viral receptor [ 16 ]. Additionally, another study has identified bat coronaviruses related to MERS-CoV that also use ACE2 as their viral receptor [ 17 ]. These findings suggest that receptor usage of these coronaviruses switched from ACE2 to DPP4 (or from DPP4 to ACE2) during their recent evolution.…”

ACE2 fromPipistrellus abramusbats is a receptor for HKU5 coronaviruses

“…While MERS-CoV uses the receptor dipeptidyl peptidase IV (DPP4) to infect cells, several studies have shown that some bat merbecoviruses do not use DPP4 and instead use angiotensin converting enzyme 2 (ACE2) to infect their hosts [21][22][23] .…”