Evidence map›Paper›PMID 42555668›Full record

ArticlePLoS pathogens2026

A novel dimerization site in non-structural protein 5A of hepatitis C virus regulates viral replication fitness.

Paul Rothhaar, Thibault Tubiana, Colin Förster, Gabriel Vanegas Arias, Tomke Arand, Noemi Schäfer, Philipp Ralfs, Christian Heuss, Antonio Piras, Andreas Pichlmair and 3 more

Abstract read
In one paragraph

Article in PLoS pathogens, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Paul RothhaarDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Thibault TubianaUniversité Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.
Colin FörsterDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Gabriel Vanegas AriasUniversité Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.
Tomke ArandDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Noemi SchäferDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Philipp RalfsDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Christian HeussDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.
Antonio PirasInstitute of Virology, Technical University of Munich, School of Medicine, Munich, Germany.
Andreas PichlmairInstitute of Virology, Technical University of Munich, School of Medicine, Munich, Germany.
Xavier HanoulleUniv. Lille, CNRS, Institut Pasteur Lille, UMR 9031 - Integrative Structural Biology, Lille, France.
Stéphane BressanelliUniversité Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France.
Volker LohmannDepartment of Infectious Diseases, Molecular Virology, Section virus-host interactions, Heidelberg University, Heidelberg, Germany.ORCID 0000-0001-8719-7608

Funding

Deutsche Forschungsgemeinschaft (DFG, German Research FoundationDZIF academyFrench agency ANRS-Maladies infectieuses émergentes (ANRS-MIE)
6 · The paper itself

Abstract

We previously found that high genome replication fitness of the hepatitis C virus (HCV) was associated with severe disease in immunocompromised patients. Elevated replication fitness was mediated by accumulation of mutations in the replication enhancing domain (ReED) within domain (D) 2 of non-structural protein (NS) 5A. NS5A is a partially unstructured phosphoprotein lacking enzymatic activity but fulfilling a key role in HCV replication due to interacting with various cellular and viral proteins. It can exist in a variety of dimeric and oligomeric conformations mediated by NS5A D1 with clinically approved NS5A inhibitors proposed to exert their antiviral function by fixing these dimers in distinct conformations. In this study, we aimed at elucidating the ReED's mode of action. AlphaFold modelling indicated a so far unrecognized NS5A dimerization site in the ReED. Indeed, split nano luciferase assays revealed a significantly stronger NS5A dimerization of high replicator ReED variants, suggesting that high replication fitness is mediated by enforcement of NS5A self-interaction. This hypothesis was supported by the effect of low dose (1 pM) NS5A inhibitor treatment, increasing replication fitness and phenocopying the effects of ReED mutations. Furthermore, we found that HCV isolate JFH1, replicating with very high efficiency, is completely resistant to the regulatory function of the ReED. Chimeric replicons composed of ReED resistant JFH1 and the ReED sensitive isolate J6 identified NS3 helicase and NS5B polymerase as critical genetic elements mediating ReED sensitivity/resistance. Our data overall suggest that the ReED in NS5A is a negative regulator of HCV replication fitness with dimerization releasing the inhibitory interaction with helicase and/or polymerase, thereby likely facilitating initiation of RNA synthesis.

Indexed as

HepacivirusRNA ReplicationViral Nonstructural ProteinsVirus ReplicationHumansMutationProtein MultimerizationRNA-Dependent RNA PolymeraseNS-5 protein, hepatitis C virusRNA-Dependent RNA PolymeraseViral Nonstructural Proteins

Identifiers

PMID42555668
PMCPMC13472503

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.