TheRhinolophus affinisbat ACE2 and multiple animal orthologs are functional receptors for bat coronavirus RaTG13 and SARS-CoV-2

Abstract

Bat coronavirus (CoV) RaTG13 shares the highest genome sequence identity with SARS-CoV-2 among all known coronaviruses, and also uses human angiotensin converting enzyme 2 (hACE2) for virus entry. Thus, SARS-CoV-2 is thought to have originated from bat. However, whether SARS-CoV-2 emerged from bats directly or through an intermediate host remains elusive. Here, we found that Rhinolophus affinis bat ACE2 (RaACE2) is an entry receptor for both SARS-CoV-2 and RaTG13, although RaACE2 binding to the receptor binding domain (RBD) of SARS-CoV-2 is markedly weaker than that of hACE2. We further evaluated the receptor activities of ACE2s from additional 16 diverse animal species for RaTG13, SARS-CoV, and SARS-CoV-2 in terms of S protein binding, membrane fusion, and pseudovirus entry. We found that the RaTG13 spike (S) protein is significantly less fusogenic than SARS-CoV and SARS-CoV-2, and seven out of sixteen different ACE2s function as entry receptors for all three viruses, indicating that all three viruses might have broad host rages. Of note, RaTG13 S pseudovirions can use mouse, but not pangolin ACE2, for virus entry, whereas SARS-CoV-2 S pseudovirions can use pangolin, but limited for mouse, ACE2s enter cells. Mutagenesis analysis revealed that residues 484 and 498 in RaTG13 and SARS-CoV-2 S proteins play critical roles in recognition of mouse and human ACE2. Finally, two polymorphous Rhinolophous sinicus bat ACE2s showed different susceptibilities to virus entry by RaTG13 and SARS-CoV-2 S pseudovirions, suggesting possible coevolution. Our results offer better understanding of the mechanism of coronavirus entry, host range, and virus-host coevolution.

There is no evidence of SARS‐CoV‐2 laboratory origin: Response to Segreto and Deigin (DOI: 10.1002/bies.202000240)

“…However, in a recent work it was shown that the ACE2 receptor of R. affinis bats can effectively bind and mediate the entry of both RaTG13 and SARS‐CoV‐2 viruses in a pseudovirus assay. [ 11 ] Therefore, the recombination may have occurred in cells of horseshoe bats. Notably, a high frequency of recombination events has been shown between SARS‐like bat coronaviruses presumably involved in the emergence of SARS‐CoV in 2002.…”

SARS-CoV-2's origin should be investigated worldwide for pandemic prevention

“…Such investigations would include testing wild animal hosts of coronaviruses at the nucleic acid and serum levels to positively identify the natural origin of the cross-species spillover. Various studies 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 have already reported that several species of mammals (including mink, civets, cats, pangolins, rabbits, ferrets, foxes, deer, etc) are capable of being infected by SARS-CoV-2. It is entirely possible that SARS-CoV-2-related viruses could cross the species barrier between humans and animals repeatedly in many parts of the world.…”

“… 64 , 65 , 66 , 67 Moreover, Chinese scientists have conducted a series of research projects to investigate the origin of SARS-CoV-2 since the COVID-19 outbreak, and have made much progress in understanding epidemiology, infection mechanisms, and animal host searching. 30 , 34 , 35 , 68 , 69 …”