Biology subjects

Rundlet, E. J.

Publications and source records attributed to Rundlet, E. J..

3 recordsLinked to original sources

bioRxiv2025

Antigen-agnostic identification of poxvirus broadly neutralizing antibodies targeting OPG153

Recurrent mpox outbreaks caused by the monkeypox virus (MPXV) have prompted the World Health Organization to declare a Public Health Emergency of International Concern and have stimulated the development of medical interventions. Here, antigen-agnostic isolation of neutralizing monoclonal antibodies from convalescent or vaccinated people, AlphaFold 3-based predictive modeling, and cryo-electron microscopy were synergistically combined to identify the protein encoded by orthopoxviral gene (OPG) 153 (MPXV A28) as a target of broadly neutralizing antibodies. OPG153-targeting antibodies neutralized MPXV clade Ib, IIb, and vaccinia virus (VACV), and cross-reacted with OPG153 orthologs from cowpox and variola viruses. Immunization with MPXV OPG153 elicited a potent neutralizing antibody response against MPXV and VACV, substantiating OPG153 as a promising vaccine antigen and a potent target for preventive and therapeutic antibodies.

microbiology↗

bioRxiv2022

Didemnin B and ternatin-4 inhibit conformational changes in eEF1A required for aminoacyl-tRNA accommodation into mammalian ribosomes

Rapid and accurate mRNA translation requires efficient codon-dependent delivery of the correct aminoacyl-tRNA (aa-tRNA) to the ribosomal A site. In mammals, this fidelity-determining reaction is facilitated by the GTPase elongation factor-1 alpha (eEF1A), which escorts aa-tRNA as an eEF1A(GTP)-aa-tRNA ternary complex into the ribosome. Two structurally unrelated cyclic peptides didemnin B and ternatin-4 bind to the eEF1A(GTP)-aa-tRNA ternary complex and inhibit translation. Here, we employ single-molecule fluorescence imaging and cryogenic electron microscopy to determine how these natural products inhibit translational elongation on mammalian ribosomes. By binding to a common allosteric site on eEF1A, didemnin B and ternatin-4 trap eEF1A in its GTPase-activated conformation, preventing aa-tRNA accommodation on the ribosome. We also show that didemnin B and ternatin-4 exhibit distinct effects on aa-tRNA selection that inform on observed disparities in their inhibition efficacies and physiological impacts. These integrated findings highlight the potential of single-molecule methods to reveal how distinct natural products differentially impact the human translation mechanism.

biochemistry↗

bioRxiv2021

Architecture of the cytoplasmic face of the nuclear pore

The nuclear pore complex (NPC) is the sole bidirectional gateway for nucleocytoplasmic transport. Despite recent progress in elucidating the NPC symmetric core architecture, the asymmetrically decorated cytoplasmic face, essential for mRNA export and a hotspot for nucleoporin-associated diseases, has remained elusive. Here, we report a composite structure of the entire human cytoplasmic face obtained by combining biochemical reconstitution, crystal structure determination, docking into cryo-electron tomographic reconstructions, and physiological validation, accounting for a third of the NPCs mass. Whereas an evolutionarily conserved [~]540 kDa hetero-hexameric cytoplasmic filament nucleoporin complex is anchored by species-specific motifs above the central transport channel, attachment of the pentameric NUP358 bundles depends on the double-ring arrangement of the coat nucleoporin complex. Our results and the predictive power of our composite structure provide a rich foundation for elucidating the molecular basis of mRNA export and nucleoporin diseases. One sentence summaryAn interdisciplinary analysis established the near-atomic molecular architecture of the cytoplasmic face of the human nuclear pore complex.

biochemistry↗