Reprogramming Host Ubiquitination: PROTAC-Induced
Degradation of Enteroviral 2C Helicase
B. Kaščáková1, D. L. Hurdis2, J.
Wuyts3, D. Jochmans4, A. Brancale5, F. J. M.
van Kuppeveld2 and I. Kutá Smatanová1
1Department of
Chemistry, University of South Bohemia, Branišovská 1645/31a, 370 05 Ceske
Budejovice, Czech Republic
2Section of Virology,
Division of Infectious Diseases & Immunology, Faculty of Veterinary
Medicine, Utrecht University, Androclus Building, Room 512 , Yalelaan 1 , 3584
CL Utrecht ,The Netherlands
3CISTIM Leuven vzw,
Leuven, Belgium
4 Virology, Antiviral
Drug & Vaccine Research Group, Department of Microbiology, Immunology and
Transplantation, Rega Institute, KU Leuven, Leuven, Belgium
5Department of Organic
Chemistry, University of Chemistry and Technology Prague, Prague 6 16628, Czech
Republic
karafb00@jcu.cz
Enteroviruses (EV), including EV-A71,
CV-B3, poliovirus, and EV-D68, are significant human pathogens associated with
neurological and respiratory disease, including acute flaccid myelitis and
severe respiratory illness [1-3]. Despite their
clinical impact, targeted antiviral therapies remain lacking [1].
The nonstructural protein 2C is considered
a high-priority antiviral target because it is highly conserved across
enteroviruses and is functionally essential [1, 4]. As a superfamily 3 helicase
and AAA+ ATPase, 2C contributes to RNA remodeling, viral RNA synthesis,
replication organelle formation, membrane rearrangement, genome replication,
and encapsidation [5-7]. Mutational analyses show that disrupting 2C function
severely impairs viral RNA replication and virion production [5].
Despite its attractiveness as a target,
conventional inhibition of 2C is challenging because the protein forms dynamic
oligomeric assemblies and is often inhibited through allosteric pockets rather
than the catalytic site [6, 8]. Existing inhibitors, including fluoxetine and
dibucaine, act allosterically by stabilizing an inactive hexameric state [8, 9].
Emerging compounds such as 12b and SJW-2C-227 target conserved 2C pockets and
show promising broad-spectrum antiviral activity. Notably, resistance mutations
often reduce viral fitness, highlighting the evolutionary constraints on 2C
function [10].
To overcome the limitations of classical
inhibition, we propose a targeted protein degradation strategy based on
proteolysis-targeting chimeras (PROTACs) that recruit the cereblon E3 ubiquitin
ligase to induce degradation of 2C. This is a rationale rather than a published
2C-specific result, but the broader antiviral concept is supported by
CRBN-recruiting degraders that eliminate viral proteins and can reduce
susceptibility to resistance mutations. This approach could, in principle,
enable complete removal of the target protein and may reduce resistance
development.
Structure-guided design is supported by
X-ray crystallography and cryo-EM studies that define ligandable sites and
oligomeric assemblies of 2C [8].
This work establishes a platform for
degrader-based antivirals targeting conserved viral proteins, with potential
broad-spectrum applicability against enteroviruses.
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targets an allosteric site in the enterovirus 2C AAA+ ATPase and stabilizes a
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doi:10.1126/sciadv.abj7615
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Screening of a Library of FDA-Approved Drugs Identifies Several Enterovirus
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This project has received funding
from the European Union’s Horizon Europe research and innovation programme
under Grant Agreement no. 101137229.