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Biology subjects

Serebryannyy, L.

Publications and source records attributed to Serebryannyy, L..

6 recordsLinked to original sources

Endothelial protein C receptor is an entry receptor for Langya and related parahenipaviruses

Langya virus is a zoonotic parahenipavirus with pandemic potential that causes acute febrile illness in people. We identified endothelial protein C receptor (EPCR) as an entry receptor for Langya, Wenzhou, and Mojiang parahenipaviruses. A 3.1 [A] cryo-electron microscopy structure reveals that Langya attachment glycoprotein engages EPCR through a site distinct from that of the ephrin binding site of Nipah G. This binding mode resembles those of protein C and a malarial adhesin, demonstrating convergent evolution. Interface substitutions abolish entry, whereas natural variation explains differential human EPCR use and predicts receptor compatibility across 26 animal species. These findings establish EPCR as a receptor for the Langya clade and provide a structural framework for understanding cross-species transmission and human infection potential.

microbiology↗

Stability of Antibody Repertoires in Astronauts During Long-Term Spaceflight

Long-duration spaceflight is known to disrupt several aspects of immune function yet its impact on the antiviral antibody repertoire remains unclear. We analyzed longitudinal plasma samples from 11 astronauts participating in a 6-month long spaceflight, including preflight, inflight, and postflight timepoints. Using a high-throughput serological method based on phage display of linear peptides from thousands of viruses we assessed the stability of antiviral antibodies over time. Across two phage libraries expressing different pathogen panels, we detected antibodies against Alphainfluenzavirus, Betainfluenzavirus, Enterovirus, and Orthopneumovirus consistently with the highest abundancy in all astronauts over all timepoints. Antibody levels against these infectious agents remained remarkably stable within individuals during and after spaceflight. In contrast, substantial heterogeneity was observed among astronauts, reflecting individualized immune histories and baseline antibody profiles. These results were confirmed by a different immunoassay using whole protein from the most targeted viruses. Together, these findings demonstrate that the antiviral antibody repertoire is largely resilient during prolonged spaceflight, highlighting preserved humoral memory despite potential dysregulation in cellular immune compartments.

immunology↗

Aminopeptidase N is a receptor for hedgehog merbecoviruses

Merbecoviruses, closely related to the highly pathogenetic Middle East Respiratory Syndrome Coronavirus (MERS-CoV), circulate in hedgehogs throughout Europe and Asia, raising concerns about zoonotic transmission to humans and domestic animals. Unfortunately, how these viruses enter host cells remains unknown, hindering experimental studies. Here, we tested known coronavirus receptor orthologues from European hedgehogs (Erinaceus europaeus) and identified Aminopeptidase N (APN) as an entry receptor for hedgehog merbecoviruses. We confirm this result with single-cycle pseudotype and replication-competent virus experiments as well as protein binding assays. A screen of 30 mammalian APN orthologues reveals restricted cross-species receptor use. Cryo-electron microscopy analysis of the viral glycoprotein-receptor complex shows a unique interface distinct from known coronavirus spike:APN interactions, providing a molecular basis for species barriers. These findings expand the known range of receptor use not only within merbecoviruses but also betacoronaviruses, improving our understanding of betacoronavirus receptors, and informing risk assessments for viral emergence.

microbiology↗

HKU5 bat merbecoviruses use divergent mechanisms to engage bat and mink ACE2 as entry receptors

Identifying receptors for bat coronaviruses is critical for spillover risk assessment, countermeasure development, and pandemic preparedness. While Middle East respiratory syndrome coronavirus (MERS-CoV) uses DPP4 for entry, the receptors of many MERS-related betacoronaviruses remain unknown. The bat merbecovirus HKU5 was previously shown to have an entry restriction in human cells. Using both pseudotyped and full-length virus, we show that HKU5 uses Pipistrellus abramus bat ACE2 but not human ACE2 or DPP4 as a receptor. Cryo-electron microscopy (cryo-EM) analysis of the virus-receptor complex and structure-guided mutagenesis reveal a spike and ACE2 interaction that is distinct from other ACE2-using coronaviruses. MERS-CoV vaccine sera poorly neutralize HKU5 informing pan-merbecovirus vaccine design. Notably, HKU5 can also engage American mink and stoat ACE2, revealing mustelids as potential intermediate hosts. These findings highlight the versatility of merbecovirus receptor use and underscore the need for continued surveillance of bat and mustelid species.

microbiology↗

HiPLA: High-throughput imaging Proximity Ligation Assay

Protein-protein interactions are essential for cellular structure and function. To delineate how the intricate assembly of protein interactions contribute to cellular processes in health and disease, new methodologies that are both highly sensitive and can be applied at large scale are needed. Here, we develop HiPLA (high-throughput imaging proximity ligation assay), a method that employs the antibody-based proximity ligation assay in a high-throughput imaging screening format to systematically probe protein interactomes. Using HiPLA, we probe the interaction of 60 proteins and associated PTMs with the nuclear lamina in a model of the premature aging disorder Hutchinson-Gilford progeria syndrome (HGPS). We identify a subset of proteins that differentially interact with the nuclear lamina in HGPS. In combination with quantitative indirect immunofluorescence, we find that the majority of differential interactions were accompanied by corresponding changes in expression of the interacting protein. Taken together, HiPLA offers a novel approach to probe cellular protein-protein interaction at a large scale and reveals mechanistic insights into the assembly of protein complexes.

cell biology↗

Single molecule analysis of lamin dynamics

The nuclear envelope (NE) is an essential cellular structure that contributes to nuclear stability, organization, and function. Mutations in NE-associated proteins result in a myriad of pathologies with widely diverse clinical manifestations, ages of onsets, and affected tissues. Notably, several hundred disease-causing mutations have been mapped to the LMNA gene, which encodes the intermediate filament proteins lamin A and C, two of the major architectural components of the nuclear envelope. However, how NE dysfunction leads to the highly variable pathologies observed in patient cells and tissues remains poorly understood. One model suggests alterations in the dynamic properties of the nuclear lamina and its associated proteins contribute to disease phenotype. Here, we describe the application of single molecule tracking (SMT) methodology to characterize the behavior of nuclear envelope transmembrane proteins (NETs) and nuclear lamins in their native cellular environment at the single molecule level. As proof-of-concept, we demonstrate by SMT that Halo-tagged lamin B1, Samp1, lamin A, and lamin A {Delta}50 have distinct binding and kinetic properties, and we identify several disease-relevant mutants which exhibit altered binding dynamics. SMT is also able to separately probe the dynamics of the peripheral and the nucleoplasmic populations of lamin A mutants. We suggest that SMT is a robust and sensitive method to investigate how pathogenic mutations or cellular processes affect protein dynamics at the NE.

cell biology↗