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O'nyong-nyong virus adaptive mutations in non-structural protein 1 and 3 enhance RNA replication and overcome FHL1 requirement.

Tessy A H Hick·Karsten Cirksena·Magnus Evander·Gisa Gerold
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Abstract

Arthritogenic alphaviruses, like o'nyong-nyong virus (ONNV), cause debilitating musculoskeletal diseases and are geographically expanding. To predict their emergence, we seek to better understand evolutionary mechanisms that enable changes in virus tropism. Here, we identify adaptive mutations in the ONNV non-structural proteins (nsPs) that arose during cellular serial passaging and enabled ONNV to infect non-permissive Lunet cells. Using shotgun proteomics, we show that this human hepatoma cell line lacks the four-and-a-half-LIM domain protein 1 (FHL1), an essential host factor in ONNV RNA replication. Individual single nucleotide mutations in the nsP1 ring-aperture membrane-binding and oligomerization domain, the nsP3 macrodomain, and the nsP3 opal stop codon overcome FHL1 deficiency in Lunet cells by enhanced RNA replication. These findings demonstrate how subtle genomic changes in nsPs can profoundly influence alphavirus replication and tropism.

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LIM Domain ProteinsHumansRNA ReplicationViral Nonstructural ProteinsMutationIntracellular Signaling Peptides and ProteinsMuscle ProteinsAlphavirusVirus ReplicationCell Line, TumorRNA, ViralFHL1adaptive mutationsnon-structural proteinso’nyong-nyong virusJournal Article

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Tessy A H Hick, Karsten Cirksena, Magnus Evander, Gisa Gerold. 2026-08-29. O'nyong-nyong virus adaptive mutations in non-structural protein 1 and 3 enhance RNA replication and overcome FHL1 requirement.. https://doi.org/10.1080/22221751.2026.2721742

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Journal Article resourceCell Line, Tumor subjectHumans subjectJournal Article subjectMutation subject

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