HKU25 clade #MERS-related #coronaviruses use #ACE2 as a functional #receptor

 

Abstract

Dipeptidyl peptidase-4 (DPP4) is an established receptor for Middle East respiratory syndrome-related coronaviruses (MERSr-CoVs), while recent studies have identified angiotensin-converting enzyme 2 (ACE2) usage in multiple merbecovirus clades. Yet, receptor usage of many genetically diverse bat MERSr-CoVs remains unclear. Here we show that broadly distributed HKU25 clade merbecoviruses use ACE2, rather than DPP4, as their receptor. Cryo-electron microscopy revealed that HsItaly2011 and VsCoV-a7 strains engage ACE2 similarly to HKU5 but with remodelled interfaces and distinct orthologue selectivity, suggesting a shared evolutionary origin of ACE2 recognition. EjCoV-3, a close relative of the DPP4-using BtCoV422, showed broad multi-species ACE2 tropism and preadaptation to human ACE2. Several ACE2 glycans and residues within or near the binding interface were identified as determinants of orthologue selectivity. These viruses remain sensitive to several broadly neutralizing antibodies and entry inhibitors, indicating potential countermeasures for future outbreaks. These findings highlight the versatility of ACE2 as a functional receptor for diverse coronaviruses.

Source: Nature Microbiology, https://www.nature.com/articles/s41564-025-02152-y

____

HKU5 #bat #merbecoviruses engage bat and #mink #ACE2 as entry #receptors

Abstract

Identifying receptors for bat coronaviruses is critical for spillover risk assessment, countermeasure development, and pandemic preparedness. While Middle East respiratory syndrome coronavirus (MERS-CoV) uses DPP4 for entry, the receptors of many MERS-related betacoronaviruses remain unknown. The bat merbecovirus HKU5 was previously shown to have an entry restriction in human cells. Using both pseudotyped and full-length virus, we show that HKU5 uses Pipistrellus abramus bat ACE2 but not human ACE2 or DPP4 as a receptor. Cryo-electron microscopy analysis of the virus-receptor complex and structure-guided mutagenesis reveal a spike and ACE2 interaction that is distinct from other ACE2-using coronaviruses. MERS-CoV vaccine sera poorly neutralize HKU5 informing pan-merbecovirus vaccine design. Notably, HKU5 can also engage American mink and stoat ACE2, revealing mustelids as potential intermediate hosts. These findings highlight the versatility of merbecovirus receptor use and underscore the need for continued surveillance of bat and mustelid species.

Source: Nature Communications, https://www.nature.com/articles/s41467-025-61583-7

____