Interaction and co-phase separation of SARS-CoV-2 nucleocapsid protein and human hnRNPA1 and its implications for viral life cycle

Gupta, P.; Sahu, R.; Nandi, I.; Setty, S. R. G.; Das, S.; Singh, M.

doi:10.1101/2025.11.28.691101

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bioRxiv · 10.1101/2025.11.28.691101

Interaction and co-phase separation of SARS-CoV-2 nucleocapsid protein and human hnRNPA1 and its implications for viral life cycle

Gupta, P.·Sahu, R.·Nandi, I.·Setty, S. R. G.·Das, S.·Singh, M.

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Abstract

The nucleocapsid (N) protein of SARS-CoV-2 is central to viral assembly and replication. It binds viral RNA to form a helical nucleocapsid and enabling genome packaging and release into host cells. Human hnRNPA1, one of the most abundant RNA-binding proteins in eukaryotes, regulates key aspects of RNA metabolism, including splicing, transcription, localisation, and transport. Here, we report a direct physical interaction between SARS-CoV-2 N protein and hnRNPA1 with moderate affinity (Kd [~] 0.18 M), primarily mediated through their intrinsically disordered regions. Furthermore, we found that these proteins co-phase separate in vitro and co-localise within stress granules in cells. In vivo studies reveal that hnRNPA1 suppresses viral replication, suggesting that the N protein - hnRNPA1 interaction plays an important role in modulating the viral life cycle.

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Gupta, P., Sahu, R., Nandi, I., Setty, S. R. G., Das, S., Singh, M.. 2025-11-28. Interaction and co-phase separation of SARS-CoV-2 nucleocapsid protein and human hnRNPA1 and its implications for viral life cycle. https://doi.org/10.1101/2025.11.28.691101

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