Back

Nsp3 Ubl1-orchestrated dephosphorylation of N protein promotes coronaviral subgenomic RNA synthesis

Zhu, J.; Chiang, C.; Gack, M.

2026-09-26 microbiology
10.64898/2026.09.25.754410 bioRxiv
Show abstract

The coronavirus nucleocapsid (N) protein is indispensable for the viral lifecycle as part of the viral Replication-Transcription Complex together with Nsp3. Recent research demonstrated that phosphorylation of N by several host kinases intricately regulates its functions during infection. However, the mechanisms that control N dephosphorylation, and its physiological consequence, remain poorly understood. Here, we show that SARS-CoV-2 Nsp3 is a key orchestrator of N dephosphorylation by recruiting the phosphatase PP1/{gamma} via a conserved PP1-binding motif in the Ubl1 domain. Disruption of this motif abolishes N dephosphorylation and selectively impairs subgenomic RNA synthesis. Comparative interactome proteomics analysis of phospho-mimic vs. phospho-deficient N, together with functional validation, revealed that the host splicing factor SRSF1 cooperates with unphosphorylated N to promote subgenomic RNA transcription. These findings uncover an unrecognized mechanism in which Nsp3-guided N dephosphorylation by PP1/{gamma} enables coronavirus subgenomic RNA replication and highlight a potentially targetable axis for antiviral intervention.

Matching journals

The top 5 journals account for 50% of the predicted probability mass.

50% of probability mass above

"Similar papers" are the closest papers from that journal in the model's embedding space. They show what the match is built on, but the ranking comes mostly from a classifier over the whole training set, not from these examples alone.