Biology subjects

Edwards, T. A.

Publications and source records attributed to Edwards, T. A..

9 recordsLinked to original sources

bioRxiv2026

EG-BINN: Parameter-Efficient Ensembling of Gated Biologically Informed Neural Networks for Epigenetic Age Estimation

Epigenetic aging clocks are widely used to evaluate biological aging, disease risk, and clinical interventions. However, most existing clocks rely on linear models that overlook nonlinear relationships between age and methylation patterns, or on deep learning architectures that are parameter-intensive and difficult to interpret. We developed EG-BINN, a parameter-efficient ensemble of biologically informed neural networks that uses sample-specific gating to modulate representations across biologically annotated nodes. Trained on 93 multi-tissue datasets, EG-BINN achieved the lowest mean and median absolute errors among matched linear and nonlinear baselines in five-fold cross-validation, as well as the lowest mean absolute and root mean squared errors across eight held-out Gene Expression Omnibus (GEO) datasets. Analysis of the gating mechanism revealed widespread associations between pathway gate values and age, including trajectories that varied across blood, adipose tissue, skeletal muscle, and liver. Across 11 TCGA cohorts, EG-BINN identified significant tumor--normal differences in residual epigenetic age acceleration in six cohorts, whereas Shapley additive explanations (SHAP) highlighted recurrent pathway nodes contributing to tumor age predictions. EG-BINN combines accurate pan-tissue age prediction with an explainable architecture for examining biologically labeled nodes across age, tissue, and disease contexts.

bioinformatics↗

bioRxiv2026

MethylCurate: Tool For Dataset Curation and Epigenetic Aging Clock Evaluation

SummaryDNA methylation datasets from public repositories such as NCBI Gene Expression Omnibus are central to the development and evaluation of epigenetic aging clocks, yet existing resources and tools do not fully resolve the bottlenecks of dataset retrieval and metadata harmonization. Current benchmarking frameworks often rely on static curated collections, support only a subset of available Gene Expression Omnibus studies, focus on specific tissues, or require substantial manual intervention when metadata fields and supplementary files are inconsistently structured across studies. We developed MethylCurate, an agentic AI framework that addresses these limitations by automating the retrieval of DNA methylation datasets from the Gene Expression Omnibus, harmonizing heterogeneous metadata, mapping datasets to a unified format, and enabling scalable evaluation of epigenetic aging clocks through an integrated, dialogue-driven workflow. Availability and ImplementationMethylCurate is implemented in Python and combines deterministic modules for Gene Expression Omnibus dataset retrieval, quality control, and clock evaluation with large language model-assisted agents for metadata extraction, metadata harmonization, and DNA methylation data parsing. Source code, documentation, and example workflows are available at: https://github.com/Travyse/methylcurate Contacttravyse.edwards@pennmedicine.upenn.edu Supplementary InformationSupplementary data are available at Bioinformatics online. Graphical AbstractMethylCurate is an agentic-AI framework that converts user-specified NCBI Gene Expression Omnibus DNA methylation datasets into standardized metadata, beta matrices, artifacts, logs, and aging clock benchmarking outputs through automated retrieval, quality control, metadata extraction, harmonization, and evaluation workflows. Figure generated with Biorender. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=51 SRC="FIGDIR/small/723515v1_ufig1.gif" ALT="Figure 1"> View larger version (12K): org.highwire.dtl.DTLVardef@197c0fborg.highwire.dtl.DTLVardef@1feace4org.highwire.dtl.DTLVardef@108b0d5org.highwire.dtl.DTLVardef@191a1b8_HPS_FORMAT_FIGEXP M_FIG C_FIG Key MessagesO_LIAutomated curation of DNA methylation datasets from the Gene Expression Omnibus. C_LIO_LIStandardized preprocessing and metadata harmonization. C_LIO_LIIntegrated benchmarking of epigenetic aging clocks. C_LI

bioinformatics↗

bioRxiv2025

Coiled-coil scaffolds for Targeted Protein Degradation

In targeted protein degradation (TPD) the cells quality control machinery is co-opted to degrade proteins of interest. Currently TPD is limited by the availability of small-molecule binders for targets and the many potential human E3 ubiquitin ligases. Consequently, other approaches are needed to tackle new targets and to exploit degradation pathways fully. The natural binding epitopes for E3s and other degradation machineries are often short linear peptide motifs, which offer routes to new biologics-based degraders. Here, targeting the anti-apoptotic BCL-xL and initiation of apoptosis, we show that several protein-degradation pathways--ubiquitination, direct proteasome, autophagy-lysosome recruitment--can be leveraged by integrating target-binding and degradation motifs into single-polypeptide constructs. This exploits versatile and varied de novo coiled-coil scaffolds as adaptable molecular glues by presenting motifs multivalently and in diverse arrangements. The constructs are small ({approx}80 residues) and provide a plug-and-play platform to map and optimise target-degradation space using rational design. We call this Coiled Coils for induced Proximity (CoCoProx) and propose its use for targeted degradation and other induced-proximity reactions.

synthetic biology↗

bioRxiv2025

De novo designed bifunctional proteins for targeted protein degradation

Targeted protein degradation (TPD) is a therapeutic strategy to remove disease-causing proteins by routing them to the ubiquitin-proteasome, autophagy, or lysosme machineries. For instance, proteolysis-targeting chimeras (PROTACs) are synthetic hetero-bifunctional small molecules that simultaneously bind the target and an E3 ubiquitin ligase to drive ubiquitination and degradation by the proteasome. Despite considerable success, designing such molecules is challenging and the number of currently addressable ubiquitin E3 ligases is limited. Here we demonstrate hetero-bifunctional de novo designed proteins as alternatives for TPD to access more targets and ligases. First, we develop a stable and highly adaptable helix-turn-helix scaffold for presenting different binding sites. Next, we use computational protein design to incorporate and embellish hot-spot-binding sites to target BCL-xL, plus short linear motifs (SLiMs) for KLHL20 ligase recruitment. The resulting mono- and bi-functionalised proteins bind the targets in vitro, and the latter degrade BCL-xL in cells leading to apoptosis.

synthetic biology↗

bioRxiv2023

The virus-encoded ion channel "viroporin" activity of the agnoprotein is required for BK Polyomavirus release from infected kidney cells

BK polyomavirus (BKPyV) is a common opportunistic pathogen and the causative agent of several diseases in transplant patients and the immunosuppressed. Despite its importance, aspects of the virus lifecycle such as how the virus exits an infected cells, remain poorly understood. The late region of the BKPyV genome encodes an auxillery protein called agnoprotein. We and others have shown that agnoprotein is an essential factor in virus release, and the loss of agnoprotein results in an accumulation of virus particles within the nucleus of an infected cell. The functions of agnoprotein necessary for this egress phenotype are not known. Here we demonstrate that agnoprotein shows properties associated with viroporins, a group of virus-encoded membrane spanning proteins that play key roles in virus infection and release. We demonstrate that agnoprotein oligomerises and perturbs membranes in cells. The development of a novel recombinant agnoprotein expression system permitted the identification of the first small molecules targeting agnoprotein. These compounds abrogated agnoprotein viroporin activity in vitro and reduced virus release, indicating that viroporin activity contributes to the phenotype observed in agnoprotein knockout viruses. The identification of channel activity should enhance the future understanding of the physiological function of agnoprotein and could represent an important target for antiviral intervention.

microbiology↗

bioRxiv2021

Understanding p300-transcription factor interactions using sequence variation and hybridization

The hypoxic response is central to cell function and plays a significant role in the growth and survival of solid tumours. HIF-1 regulates the hypoxic response by activating over 100 genes responsible for adaptation to hypoxia, making it a potential target for anticancer drug discovery. Although there is significant structural and mechanistic understanding of the interaction between HIF-1 and p300 alongside negative regulators of HIF-1 such as CITED2, there remains a need to further understand the sequence determinants of binding. In this work we use a combination of protein expression, chemical synthesis, fluorescence anisotropy and isothermal titration calorimetry for HIF-1 sequence variants and a HIF-1- CITED hybrid sequence which we term CITIF. We show the HIF-1 sequence is highly tolerant to sequence variation through reduced enthalpic and less unfavourable entropic contributions, These data imply backbone as opposed to side chain interactions and ligand folding control the binding interaction and that sequence variations are tolerated as a result of adopting a more disordered bound interaction or "fuzzy" complex.

biochemistry↗

bioRxiv2021

The structure of a native orthobunyavirus ribonucleoprotein reveals a key role for viral RNA in maintaining its helical architecture

The Bunyavirales order of RNA viruses comprises emerging pathogens for which approved preventative or therapeutic measures for human use are not available. The genome of all Bunyavirales consists of negative-sense RNA segments wrapped by the virus-encoded nucleocapsid protein (NP) to form ribonucleoproteins (RNPs). RNPs represent the active template for RNA synthesis and the form in which the genome is packaged into virions, functions that require inherent flexibility. We present a pseudo-atomic model of a native RNP purified from Bunyamwera virus (BUNV), the prototypical Bunyavirales member, based on a cryo-electron microscopy (cryo-EM) average at 13 [A] resolution with subsequent fitting of the BUNV NP crystal structure by molecular dynamics. We show the BUNV RNP possesses relaxed helical architecture, with successive helical turns separated by [~]18 [A]. The model shows that adjacent NP monomers in the RNP chain interact laterally through flexible N- and C-terminal arms, with no helix-stabilizing interactions along the longitudinal axis. Instead, EM analysis of RNase-treated RNPs suggests their chain integrity is dependent on the encapsidated genomic RNA, thus providing the molecular basis for RNP flexibility. Overall, this work will assist in designing anti-viral compounds targeting the RNP and inform studies on bunyaviral RNP assembly, packaging and RNA replication. SignificanceBunyaviruses are emerging RNA viruses that cause significant disease and economic burden and for which vaccines or therapies approved for human use do not exist. The bunyavirus genome does not exist as naked RNA; instead it is wrapped up by the nucleoprotein (NP) to form a ribonucleoprotein (RNP). Using the prototypical bunyavirus, Bunyamwera virus, we determined the 3D structure of the native RNP, revealing a helical architecture with NP molecules linked by lateral contacts only, with no helix-stabilizing longitudinal contacts. Instead, the RNA genome itself plays a role in maintaining the helical architecture, allowing a high degree of flexibility that is critical for several stages of the virus replication cycle, such as segment circularization and genome packaging into virions.

microbiology↗

bioRxiv2020

RAS-inhibiting biologics identify and probe druggable pockets including an SII-α3 allosteric site.

RAS mutations are the most common oncogenic drivers across human cancers, but there remains a paucity of clinically-validated pharmacological inhibitors of RAS, as druggable pockets have proven difficult to identify. We have identified two RAS-binding Affimer proteins, K3 and K6, that inhibit nucleotide exchange and downstream signalling pathways with distinct isoform and mutant profiles. Affimer K6 is the first biologic to bind in the SI/SII pocket, whilst Affimer K3 is the first non-covalent inhibitor of the SII region, revealing a novel RAS conformer with a large, druggable SII/3 pocket. This work demonstrates the potential of using biologics with small interface surfaces to select novel druggable conformations in conjunction with pharmacophore identification for hard-to-drug proteins.

molecular biology↗

bioRxiv2019

Selective Affimers Recognize BCL-2 Family Proteins Through Non-Canonical Structural Motifs

The BCL-2 family is a challenging set of proteins to target selectively due to sequence and structural homologies across the family. Selective ligands for the BCL-2 family regulators of apoptosis are desirable as probes to understand cell biology and apoptotic signalling pathways, and as starting points for inhibitor design. We have used phage display to isolate Affimer reagents (non-antibody binding proteins based on a conserved scaffold) to identify ligands for MCL-1, BCL-xL, BCL-2, BAK and BAX, then used multiple biophysical characterisation methods to probe the interactions. We established that purified Affimers elicit selective and potent recognition of their target BCL-2 protein. For anti-apoptotic targets, competitive inhibition of their canonical protein-protein interactions is demonstrated. Co-crystal structures reveal an unprecedented mode of molecular recognition; where a BH3 helix is normally bound, flexible loops from the Affimer dock into the BH3 binding cleft. Moreover, the Affimers induce a change in the target proteins towards a desirable drug bound like conformation. These results indicate Affimers can be used as alternative templates to inspire design of selective BCL-2 family modulators, and provide proof-of-concept for the elaboration of selective non-antibody binding reagents for use in cell-biology applications.

biochemistry↗