Biology subjects

Zollbrecht, E.

Publications and source records attributed to Zollbrecht, E..

3 recordsLinked to original sources

bioRxiv2026

The diverse functions of viral microproteins

A large fraction of the uncharacterized proteome consists of microproteins. Viruses, rich in microproteins with potent activities, provide a unique system for exploring their functions and evolution. Here, we systematically annotate viral microproteins through a phenotype-first approach: construction of a >50,000-element small ORF library spanning the microprotein-coding potential of human-infecting viruses, followed by broad screens that enrich candidates for high-resolution profiling by Perturb-seq, mass spectrometry, AI-guided structure prediction, and mechanistic studies. This atlas identified >2,000 active microproteins that modulate host pathways through diverse mechanisms, including molecular mimicry, hijacking of key regulators, and altering subcellular localization. We further show the oncogenic potential of BNLF2b, an uncharacterized Epstein-Barr virus microprotein linked to nasopharyngeal carcinoma. Three principles emerge: viral microproteins are diverse and often multifunctional, show widespread convergence toward shared functions, and serve as reservoirs of evolutionary innovation. These findings elucidate how viral microproteins occupy a large functional landscape, establish them as versatile tools for host manipulation, and provide a framework for functional annotation of uncharacterized proteins, contributing toward predictive systems virology.

systems biology↗

bioRxiv2026

HIP-MS: An ultra-high-throughput, sensitive, and versatile affinity enrichment platform for static and dynamic interactome profiling

Although protein-protein interactions govern virtually all cellular processes, systematic interactome mapping by affinity enrichment mass spectrometry (AE-MS) is constrained by manual sample preparation and lengthy liquid chromatography (LC)-MS/MS acquisition. Here we present High-throughput Interactome Profiling by MS (HIP-MS), an automated, end-to-end pipeline that overcomes these limitations. It leverages the compact, high-affinity ALFA tag for on-plate nanobody capture in 384-well format, combined with on-plate tryptic digestion. It can process almost 10,000 samples per week from protein expression up to MS measurement and can be combined with ultra-fast gradient LC-MS acquisition of 500 samples per day. HIP-MS remains sensitive down to low-microgram lysate inputs, a 4,000-fold reduction compared to recent large-scale screens. Our pipeline recovers complexes from diverse cellular compartments and resolves endogenous membrane receptor signaling. HIP-MS establishes a scalable foundation for systematic interrogation of protein interactions across conditions, perturbations, and time, and for the generation of large-scale datasets for computational modeling.

systems biology↗

bioRxiv2026

Reprogramming insulin receptor activation with a de novo agonist to overcome severe insulin resistance

Computational protein engineering provides a powerful approach to address longstanding clinical challenges. Severe insulin resistance syndromes caused by mutations in the insulin receptor (IR) are life-threatening disorders for which effective long-term therapies remain lacking. Here, we define the in vivo activity and therapeutic potential of RF-409, a de novo-designed IR agonist that activates the receptor through a mechanism distinct from insulin. RF-409 exhibits markedly prolonged circulation compared to insulin and produces sustained improvements in glucose homeostasis without detectable adverse effects on body composition or liver function. In a patient-derived IR D707A mouse model of severe insulin resistance, RF-409--but not insulin--activates the mutant receptor, restoring glucose regulation and ameliorating hyperglycemia, hyperinsulinemia, lipoatrophy, and pancreatic atrophy. Mechanistically, RF-409 engages the IR through a noncanonical binding geometry while stabilizing an active conformation resembling that induced by insulin. Phosphoproteomic profiling shows that RF-409 elicits broadly insulin-like signaling with distinct temporal features in receptor-proximal regulation. Together, these findings establish a framework for reactivating dysfunctional receptors and suggest broader applications beyond rare receptoropathies, including diabetes and liver disease.

pharmacology and toxicology↗