Publicação
Exploring Nsp14 As A Drug Target Against Feline Infectious Peritonitis Virus
| Resumo: | Coronaviruses are RNA viruses infecting a wide range of animals. In cats, Feline Infectious Peritonitis (FIP), caused by Feline Coronavirus (FCoV), remains one of the deadliest diseases, with no treatment available or vaccine. Although one antiviral shows partial efficacy, its high cost, limited accessibility, and potential for resistance show that there is an urgent need for new therapeutic strategies. FCoV encodes several non-structural proteins (Nsp), including Nsp14, a bifunctional enzyme crucial for viral replication. Nsp14 contains two catalytic domains: an N-terminal 3’-5’ exoribonuclease (ExoN), for RNA proofreading, and a C-terminal N7-methyltransferase (MTase), for RNA capping. Both are critical for genome stability and immune evasion. In other coronaviruses, such as SARS-CoV-2, ExoN activity strictly depends on the cofactor Nsp10. These proteins have no mammalian homologs, and their high conservation reduces the risk of drug resistance, making them promising antiviral targets. This work focused on the study of FCoV Nsp14 and Nsp10. These proteins were expressed, purified and subjected to activity assays. Our preliminary results suggest that FCoV Nsp14 ExoN activity may function independently of Nsp10, a feature not yet described in other coronaviruses. To explore their therapeutic potential, we tested a set of EMA- and FDA-approved compounds that had been previously selected through in silico docking based on their predicted affinity for the Nsp14 ExoN active site. From these, we identified one compound capable of inhibiting FCoV ExoN activity in vitro. This molecule represents a promising scaffold for the rational design of FIP antivirals. In summary, we provide new insights into the unique biochemical proprieties of FCoV Nsp14 and identify a candidate inhibitor of its ExoN function. Given the high sequence conservation of Nsp14 across coronaviruses, this compound also holds potential as a broad-spectrum antiviral against other coronavirus diseases. |
|---|---|
| Autores principais: | Freitas, Margarida Isabel Argente Gomes e Henriques de |
| Assunto: | Feline Coronavirus Feline Infectious Peritonitis Ribonucleases Methyltransferase Drug Repurposing |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso embargado |
| Instituição associada: | Universidade Nova de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório Institucional da UNL |
| Resumo: | Coronaviruses are RNA viruses infecting a wide range of animals. In cats, Feline Infectious Peritonitis (FIP), caused by Feline Coronavirus (FCoV), remains one of the deadliest diseases, with no treatment available or vaccine. Although one antiviral shows partial efficacy, its high cost, limited accessibility, and potential for resistance show that there is an urgent need for new therapeutic strategies. FCoV encodes several non-structural proteins (Nsp), including Nsp14, a bifunctional enzyme crucial for viral replication. Nsp14 contains two catalytic domains: an N-terminal 3’-5’ exoribonuclease (ExoN), for RNA proofreading, and a C-terminal N7-methyltransferase (MTase), for RNA capping. Both are critical for genome stability and immune evasion. In other coronaviruses, such as SARS-CoV-2, ExoN activity strictly depends on the cofactor Nsp10. These proteins have no mammalian homologs, and their high conservation reduces the risk of drug resistance, making them promising antiviral targets. This work focused on the study of FCoV Nsp14 and Nsp10. These proteins were expressed, purified and subjected to activity assays. Our preliminary results suggest that FCoV Nsp14 ExoN activity may function independently of Nsp10, a feature not yet described in other coronaviruses. To explore their therapeutic potential, we tested a set of EMA- and FDA-approved compounds that had been previously selected through in silico docking based on their predicted affinity for the Nsp14 ExoN active site. From these, we identified one compound capable of inhibiting FCoV ExoN activity in vitro. This molecule represents a promising scaffold for the rational design of FIP antivirals. In summary, we provide new insights into the unique biochemical proprieties of FCoV Nsp14 and identify a candidate inhibitor of its ExoN function. Given the high sequence conservation of Nsp14 across coronaviruses, this compound also holds potential as a broad-spectrum antiviral against other coronavirus diseases. |
|---|