Host protein ARF1 is a proviral factor for SARS-CoV-2 and a candidate broad-spectrum therapeutic target

Abstract SARS-CoV-2 and its emerging variants pose continuing threats to public health, necessitating further research into detailed infection mechanisms and broad-spectrum antiviral therapies. SARS-CoV-2 assembles at the ER–Golgi intermediate compartment (ERGIC), where the viral membrane (M) protein highly accumulates to act as the central driver of the viral morphogenesis. However, which host factors are involved in the ERGIC accumulation of M and whether they could be exploited as broad-spectrum antiviral targets remain unclear. Here, we identified an M-interacting host protein ARF1 as a proviral factor that bolsters the propagation of SARS-CoV-2 and its variants in cultured cells and the viral infection and pathogenicity in K18-hACE2 mice. Mechanistically, by interacting with M, ARF1 facilitates M accumulation to the ERGIC and thus M-driven virion production. Consistently, pharmacological ARF1 inhibition by small molecules disrupted ARF1 and M concentration at the ERGIC, blocking virion assembly and propagation. Furthermore, a designed peptide mimicking the M-targeted motif of ARF1 competitively blocked the M-ARF1 interaction, M accumulation at the ERGIC, M-driven virion assembly, and SARS-CoV-2 and its variants’ propagation in vitro. Moreover, the peptidomimetic inhibitor exhibited a therapeutic efficacy against SARS-CoV-2 infection and pathogenicity in vivo. These findings provide critical insights into the basic biology of SARS-CoV-2 propagation and show the potential to develop pan-SARS-CoV-2 therapeutic strategies by targeting ARF1 and/or the ARF1-M interaction interface.