Inhibition of VP2-mediated entry: a potential antiviral strategy to treat or prevent calicivirus disease

Lewis, C. B.; Sherry, L.; McGrory, R.; Gould, E.; Freitag, M.; Sasvari, H.; Southall, J.; Petrov, F.; Meir, A.; Govindan, N.; Spiri, A.; Bordicchia, M.; Hofmann-Lehmann, R.; Barrs, V. R.; Grove, J.; Jamieson, A.; Hosie, M. J.; Bhella, D. J.

doi:10.64898/2026.05.10.723473

bioRxiv · 10.64898/2026.05.10.723473

Inhibition of VP2-mediated entry: a potential antiviral strategy to treat or prevent calicivirus disease

Lewis, C. B.·Sherry, L.·McGrory, R.·Gould, E.·Freitag, M.·Sasvari, H.·Southall, J.·Petrov, F.·Meir, A.·Govindan, N.·Spiri, A.·Bordicchia, M.·Hofmann-Lehmann, R.·Barrs, V. R.·Grove, J.·Jamieson, A.·Hosie, M. J.·Bhella, D. J.

View original source ↗Export metadata ↓

Abstract

The Caliciviridae include many notable human and animal pathogens, including norovirus and sapovirus, which cause outbreaks of acute gastroenteritis. We previously demonstrated that, following receptor engagement, feline calicivirus (FCV) assembles a portal structure at a unique capsid three-fold axis. This comprises twelve copies of the minor capsid protein VP2 and is essential for genome delivery. We designed a short peptide based on our structure data that occludes the VP2 binding sites on the capsid surface, to prevent assembly of the VP2 portal and thereby halt the viral entry mechanism. Incubation with low micromolar concentrations of the peptide considerably reduced the infectivity of two laboratory strains and four clinical isolates of FCV associated with respiratory or virulent-systemic disease. Cryo-electron microscopy structures of FCV virions complexed with the peptide confirmed that the peptide occupies the VP2 binding site on the major capsid protein VP1, preventing portal assembly and subsequent genome delivery. Our data show that targeting VP2 is a viable antiviral approach to preventing calicivirus infection, with potential for the treatment or prevention of norovirus disease.

Explore related subjects

microbiology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Lewis, C. B., Sherry, L., McGrory, R., Gould, E., Freitag, M., Sasvari, H., Southall, J., Petrov, F., Meir, A., Govindan, N., Spiri, A., Bordicchia, M., Hofmann-Lehmann, R., Barrs, V. R., Grove, J., Jamieson, A., Hosie, M. J., Bhella, D. J.. 2026-05-10. Inhibition of VP2-mediated entry: a potential antiviral strategy to treat or prevent calicivirus disease. https://doi.org/10.64898/2026.05.10.723473

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Cryo-EM Structure of Mycobacteriophage D29 Reveals a Specialized Portal-Capsid Junction and a Unique 13-Subunit Baseplate Collar

Mycobacteriophages are promising agents against drug-resistant mycobacterial infections, yet their structural organization and host-recognition mechanisms remain poorly understood. Here, we determined cryo-EM structures of the capsid, connector, tail tube, and baseplate of the lytic, broad-host-range mycobacteriophage D29, revealing a near-complete virion architecture. At the capsid-portal interface, five copies of the previously uncharacterized protein gp19.1 bridge adjacent capsid subunits around the dodecameric portal, potentially reinforcing the symmetry-mismatched vertex. At the baseplate, 13 copies of gp6 assemble into a collar surrounding the sixfold-symmetric gp23-gp27 core. Remarkably, this 6:13 symmetry mismatch is accommodated through six distinct gp6- gp27 interfaces involving 12 gp6 subunits, leaving one subunit largely disengaged from the core. This asymmetric organization produces a tilted, outward-flaring collar that presents an extensive surface with the potential to engage the host cell. Whole-cell binding and plaque-competition assays further implicate the gp6 collar and the flexible trimeric central fiber gp31 in host recognition. Together, these findings reveal distinct structural adaptations at symmetry-mismatched interfaces and provide a structural framework for understanding mycobacteriophage assembly and host engagement.

microbiology↗

bioRxiv2026

A Luciferase Reporter of Ester Prodrug Delivery to the Cytosol of Intracellular Mycobacteria

The bacterial cell envelope restricts access to cytoplasmic targets and is a principal reason that otherwise potent antibacterial compounds fail in cells. Masking an anionic carboxylic acid as an ester is a common way to cross that barrier, but the strategy succeeds only if the target organism also hydrolyzes the ester once the compound arrives. These two requirements, permeation and intracellular unmasking, are rarely measured together in live bacterial cells, and existing reporters cannot specify where unmasking occurred. Here we describe a bioluminescent platform that resolves both steps in real time in live mycobacteria using carboxylate esters of D-luciferin. Luciferase requires that an ester both reach the bacterial cytoplasm and be hydrolyzed there, which makes light a compartment-specific readout of productive delivery. Across a series of alkyl esters in Mycobacterium smegmatis, chain length governed permeation while branching adjacent to the carbonyl governed esterase processing, indicating that the two parameters can be tuned independently. The n-butyl ester gave the strongest signal in broth, in infected macrophages, and in the pathogen Mycobacterium avium, whereas the tert-butyl ester was inert in Mycobacterium avium and unmasking of the whole series was attenuated at phagosomal pH. Ester activation is therefore both species- and compartment-dependent, and masking groups are best selected in the organism and environment in which they must act.

microbiology↗

bioRxiv2026

Flexible phosphorus allocation to the phosphoproteome underpins diatom regulatory adaptations to fluctuating phosphate supply

Diatoms are major drivers of marine phosphorus (P) cycling and are highly adapted to cope with variable P supply. P-starved diatoms can sense increases in P availability within seconds, accumulating this limiting resource through luxury polyphosphate (polyP) storage. Yet, how diatoms coordinate such responses is unknown. Protein phosphorylation is a core mechanism for environmental signal transduction in eukaryotes, but how cells balance investment in protein phosphorylation against competing physiological demands during P limitation is poorly understood. Here, we characterise system-wide remodelling of the Phaeodactylum tricornutum phosphoproteome in response to P deficiency and subsequent resupply. We identify widespread proteome dephosphorylation across 44% of phosphosites, revealing a previously unrecognised P-sparing strategy in marine phytoplankton. Following P resupply, diatoms orchestrate extensive phosphoproteome reprogramming within minutes. We characterise previously unrecognized components for early recovery from P limitation, including a novel environmentally prevalent intracellular H+/phosphate transporter strongly conserved in diverse diatoms. We also identify a vacuolar Ca2+-dependent protein kinase (CDPK) associated with polyP-storage granules. Mutant and inhibitor analyses demonstrate a role for Ca2+- and CDPK-signalling in the regulation of luxury polyP accumulation. Our findings reveal that recovery from P starvation is mediated by rapid phosphoregulatory control of intracellular P trafficking, organellar ATP generation coupled with luxury P storage, enabling diatoms to exploit newly available P and thrive in fluctuating P regimes. Collectively, our study uncovers the phosphoproteome as a flexible intracellular P reservoir and establishes mechanistic links between intracellular P budgeting, signalling and the marine P cycle.

microbiology↗