Convergent use of aminopeptidase N receptor by hedgehog merbecoviruses.

Abstract

Coronaviruses circulating in wildlife, such as European and Asian hedgehog merbecoviruses (EriCoVs), pose a potential transmission risk. Knowledge of viral receptors can inform risk assessment and development of countermeasures; however, the functional receptor for EriCoVs is unknown. Here we identify hedgehog aminopeptidase N (APN) as a functional receptor for various EriCoVs. Analysis of APN orthologues from 93 species reveals a restricted APN tropism for EriCoVs, primarily utilizing APN from hedgehogs and to a lesser extent felid APN. Cryogenic electron microscopy analysis of the EriCoV-APN complex reveals an APN-binding mode that is distinct from those used by alpha- and deltacoronaviruses. Functional assays suggest that proteolytic activation of EriCoV spikes can be facilitated by multiple proteases in a context- and strain-dependent manner. Neutralizing antibodies targeting the EriCoV receptor-binding domain and hedgehog APN effectively blocked EriCoV pseudovirus entry or amplification. Receptor-binding-domain-targeting antibodies were further elucidated by cryogenic electron microscopy analysis. Together, these findings can inform assessment of merbecovirus spillover and pathogenesis.