Biology subjects

Gruska, I.

Publications and source records attributed to Gruska, I..

5 recordsLinked to original sources

bioRxiv2026

Virion-wide interactome mapping of HSV-1 reveals maturation-dependent remodeling and convergent organization of herpesvirus tegument networks

Herpesvirus virions form by remodeling of intracellular virus-host interaction networks into evolutionarily conserved particle architectures. Here, we define a virion-wide spatial and quantitative protein proximity map of herpes simplex virus 1 (HSV-1) by combining cross-linking mass spectrometry with quantitative proteomics. Integration with intracellular interaction maps reveals that maturation acts as a selective filter, transforming broad virus-host associations into an organized virion network. This process depletes biosynthetic and nuclear components while enriching interactions involved in tegument organization and envelope acquisition around the viral protein UL49. Comparison with analogous maps of human cytomegalovirus (HCMV) identifies HSV-1-UL49 and HCMV-UL32 as functionally equivalent network hubs despite lacking evolutionary relatedness. Both hubs converge on shared phosphoregulatory host factors, short linear interaction motifs, and liquid-liquid phase separation. At the virion surface, the host complement regulator CD59 protects particles from complement-mediated inactivation. Together, these findings show how conserved organizational principles shape virus-specific virion interaction networks during herpesvirus maturation.

microbiology↗

bioRxiv2023

Structural Host-Virus Interactome Profiling of Intact Infected Cells

Virus-host protein-protein interactions (PPIs) are fundamental to viral infections, yet high-resolution identification within the native context of intact infected cells has remained an unsolved challenge. Here, we developed structural host-virus interactome profiling (SHVIP) that combines in situ cross-linking mass spectrometry with the enrichment of newly synthesized viral proteins from infected cells. We established SHVIP using herpes simplex virus type 1 and obtained 739 PPIs based on 6,194 cross-links from productively infected cells. SHVIP captures PPIs across intracellular compartments and at the intact host endomembrane system. It resolves PPIs to the protein domain level and seamlessly integrates with AlphaFold-based structural modeling, facilitating detailed predictions of PPI sites within structured and intrinsically disordered regions. We show that SHVIP captures parts of the virus-host PPI space that are elusive to traditional interaction proteomics approaches. By selectively disrupting several newly identified virus-host PPIs, we confirm SHVIPs ability to uncover genuine virus-host PPIs in the intact complex environment of infected cells.

microbiology↗

bioRxiv2023

Abemaciclib restricts HCMV replication by suppressing pUL97-mediated phosphorylation of SAMHD1

Human cytomegalovirus (HCMV) is a herpesvirus that causes life-threatening infections in newborns or immunosuppressed patients. For viral replication, HCMV establishes a network of cellular interactions, among others cyclin-dependent kinases (CDK). Furthermore, HCMV encodes pUL97, a viral kinase, which is a CDK-homologue. HCMV uses pUL97 in order to phosphorylate and thereby antagonize SAMHD1, an antiviral host cell factor. Since HCMV has several mechanisms to evade restriction by SAMHD1, we first analyzed the kinetics of SAMHD1-inactivation and found that phosphorylation of SAMHD1 by pUL97 occurs directly after infection of macrophages. We hence hypothesized that inhibition of this process qualifies as efficient antiviral target and FDA approved CDK-inhibitors (CDKIs) might be potent antivirals that prevent the inactivation of SAMHD1. Indeed, Abemaciclib, a 2nd generation CDKI exhibited superior IC50s against HCMV in infected macrophages and the antiviral activity largely relied on its ability to block pUL97-mediated SAMHD1-phosphorylation. Altogether, our study highlights the therapeutic potential of clinically-approved CDKIs as antivirals against HCMV, sheds light on their mode of action and establishes SAMHD1 as a valid and highly potent therapeutic target.

microbiology↗

bioRxiv2022

Spatial, Quantitative and Functional Deconstruction of Virus and Host Protein Interactions Inside Intact Cytomegalovirus Particles

Herpesviruses assemble large enveloped particles that are difficult to characterize structurally due to their size, fragility and complex proteome with partially amorphous nature. Here we use cross-linking mass spectrometry and quantitative proteomics to derive a spatially resolved interactome map of intact human cytomegalovirus virions. This enabled the de novo allocation of 32 viral proteins into four spatially resolved virion layers, each organized by a dominant viral scaffold protein. The viral protein UL32 engages with all layers in an N-to-C-terminal radial orientation bridging nucleocapsid to viral membrane. In addition, we observed the layer-specific recruitment of 82 host proteins, a subset of which are constitutively and selectively incorporated via specific host-virus interactions. We uncover how the recruitment of PP1 phosphatase and 14-3-3 proteins by UL32 affects early and late steps during viral biogenesis. Collectively, this study provides global structural insights into the native configuration of virus and host protein interactions inside herpesvirus particles.

microbiology↗

bioRxiv2019

Cross-regulation of viral kinases with cyclin A secures shutoff of host DNA synthesis

Herpesviruses encode conserved protein kinases to stimulate phosphorylation-sensitive processes during infection. How these kinases bind to cellular factors and how this impacts their regulatory functions is poorly understood. Here, we use quantitative proteomics to determine cellular interaction partners of human herpesvirus (HHV) kinases. We find that these kinases can target key regulators of transcription and replication. The interaction with Cyclin A and associated factors is identified as a specific signature of {beta}-herpesvirus kinases. Cyclin A is recruited via RXL-motifs that overlap with nuclear localization signals (NLS) and locate in the non-catalytic N-terminal regions. This architecture is conserved for viral kinases of HHV6, HHV7 and rodent CMVs. Docking to Cyclin A competes with NLS function, enabling dynamic changes in kinase localization and substrate phosphorylation. The viral kinase redirects Cyclin A to the cytosol, which is essential for the inhibition of cellular DNA replication during infection. Our data highlight a fine-tuned and physiologically important interplay between a cellular cyclin and viral kinases.

microbiology↗