bioRxiv Science⌕ Search

bioRxiv · 10.1101/2025.09.03.674079

Aminopeptidase N is a receptor for hedgehog merbecoviruses

Abstract

Merbecoviruses, closely related to the highly pathogenetic Middle East Respiratory Syndrome Coronavirus (MERS-CoV), circulate in hedgehogs throughout Europe and Asia, raising concerns about zoonotic transmission to humans and domestic animals. Unfortunately, how these viruses enter host cells remains unknown, hindering experimental studies. Here, we tested known coronavirus receptor orthologues from European hedgehogs (Erinaceus europaeus) and identified Aminopeptidase N (APN) as an entry receptor for hedgehog merbecoviruses. We confirm this result with single-cycle pseudotype and replication-competent virus experiments as well as protein binding assays. A screen of 30 mammalian APN orthologues reveals restricted cross-species receptor use. Cryo-electron microscopy analysis of the viral glycoprotein-receptor complex shows a unique interface distinct from known coronavirus spike:APN interactions, providing a molecular basis for species barriers. These findings expand the known range of receptor use not only within merbecoviruses but also betacoronaviruses, improving our understanding of betacoronavirus receptors, and informing risk assessments for viral emergence.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Jin, M., Jefferson, V. A., Zhao, Z., Catanzaro, N. J., De Sabato, L., Keeler, E. L., Menasche, B. L., Hoffman, C., Castelli, A., Di Bartolo, I., Vaccari, G., Starr, T. N., Seifert, S. N., Castellanos, A. A., Han, B., Serebryannyy, L., Spaulding, A. B., Douek, D. C., Moreno, A., Baric, R. S., Wilen, C. B., Rini, J. M., Letko, M. C.. 2025-09-03. Aminopeptidase N is a receptor for hedgehog merbecoviruses. https://doi.org/10.1101/2025.09.03.674079

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Characterization of Lactobacillus rhamnosus-Derived Extracellular Vesicles and Their Cellular Cytoprotective Effects Against Trimethylamine-Induced Oxidative Stress in Caco-2 Cells

Dietary trimethylamine (TMA) underwent gut microbiota-mediated catabolism and subsequent hepatic oxidation to generate trimethylamine N-oxide (TMAO), a key metabolic factor linked to vascular and colorectal diseases. While the systemic effects of circulating TMAO were heavily investigated, the direct localized cellular interactions of its precursor, TMA, at the intestinal epithelial level required further elucidation. This study characterized extracellular vesicles isolated from Lactobacillus rhamnosus (Lr-EVs) and evaluated their cytoprotective potential in an in vitro human intestinal Caco-2 cell model under TMA-induced stress. Exposure to a high concentration of TMA (20 mM) significantly reduced Caco-2 viability to 78.8%, triggered intracellular reactive oxygen species (ROS) accumulation, and compromised tight junction integrity as observed via the disruption of Zonula Occludens-1 (ZO-1) alignment. Co-treatment with Lr-EVs (100-300 g/mL) counteracted this cellular toxicity, enhancing cell survival up to 172%. Quantitative PCR analysis revealed that Lr-EVs suppressed the transcriptional upregulation of the pro-inflammatory gene IL-1{beta}, restored the expression of the metabolic regulator SIRT1, and stabilized transcript levels of key mitochondrial-encoded electron transport chain genes (ND6, CYTB, CO1, and ATP6). Additionally, Lr-EVs exhibited intrinsic radical scavenging activities in cell-free ABTS and DPPH assays. These preliminary in vitro findings demonstrated that Lr-EVs mitigated TMA-induced cellular injury, oxidative stress, and junctional disruption at the transcriptomic level, supporting further investigation of probiotic-derived EVs as prospective cell-free functional ingredients.

microbiology↗

Metagenomic Insights into the Fecal Microbiome, Resistome, and Mobilome of Beef Cattle in Cow-Calf Operations in Florida, United States

Food-producing animals are a focus of One Health approaches to antimicrobial resistance (AMR) as reservoirs of antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs). We hypothesized that microbial composition, ARGs profiles, and mobile genetic element (MGE) profiles would differ by operation size and animal age group. Fecal samples from 162 cows and calves were combined into 54 composite samples, each comprising three animals of the same age group. Across operation sizes, Bacillota (51.4-64.9%), Bacteroidota (12.0-17.3%), Pseudomonadota (10.3-16.5%), and Actinomycetota (3.3-10.9%) were predominant phyla. Alpha diversity did not differ among operation sizes; however, cows exhibited greater observed richness, Shannon diversity, and Simpson diversity than calves (all P < 0.001). Microbial composition did not differ significantly among operation sizes (PERMANOVA, R{superscript 2} = 0.065, P = 0.609) but differed significantly between cows and calves (R{superscript 2} = 0.200, P < 0.001). Seventy-five ARGs representing 14 resistance classes were identified. Normalized ARG hit rates were higher in small operations (0.444) than in medium (0.278) and large operations (0.222; P = 0.088), whereas calves exhibited a higher estimated marginal mean normalized ARG hit rate than cows (0.383 vs. 0.247 hits/million reads; P < 0.001). Of 1,054 curated ARG hits, 23.9% occurred on predicted plasmid contigs, 0.9% on predicted viral contigs, and 7.1% on contigs containing insertion sequences. Overall findings demonstrate differences in fecal microbiome diversity and ARG abundance between cows and calves and indicate that predicted plasmids are associated with a notable proportion of ARG hits in Florida beef cow-calf operations.

microbiology↗

A global post-transcriptional regulator directs Acinetobacter baumannii carbon preference and gut colonization

Acinetobacter baumannii is a multidrug-resistant pathogen that colonizes the gut, increasing the risk of subsequent infection and transmission. Recent work showed that A. baumannii catabolizes ornithine, a non-preferred carbon source, to colonize the gut. However, the mechanisms of carbon preference were unknown in A. baumannii. Here, experimental evolution identified the conserved RNA-binding protein CsrA as a regulator of carbon preference in A. baumannii, a previously unreported CsrA function. RNA immunoprecipitation sequencing (RIP-Seq) revealed hundreds of CsrA-associated transcripts. A. baumannii CsrA directly bound and repressed expression of the ast arginine/ornithine catabolic operons. The Pseudomonas aeruginosa CsrA homolog RsmA repressed arginine/ornithine catabolic operon expression, suggesting this CsrA function extends to other bacterial taxa. Finally, CsrA was required for competitive fitness during A. baumannii gut colonization. These findings uncover a previously unrecognized role for a global regulator in A. baumannii carbon preference and persistence in the gut, a critical reservoir for multidrug-resistant pathogens.

microbiology↗