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Teyra, J.

Publications and source records attributed to Teyra, J..

5 recordsLinked to original sources

Targeting IL-2 to inflamed tissues via oxidation-specific epitopes enables third-generation bispecific IL-2 therapeutics

Interleukin-2 (IL-2) is essential for the survival and activation of regulatory T cells (Tregs). Low-dose native IL-2 (IL-2LD) therapy restores immune regulation in vivo and has shown reproducible clinical benefit across multiple autoimmune, inflammatory, and neuroimmune diseases. Attempts to improve IL-2 through engineered variants (muteins) have mainly focused on enhancing Treg selectivity by reducing IL-2 receptor {beta}-chain binding, but this strategy profoundly diminishes biological potency, likely contributing to the limited clinical efficacy of IL-2 muteins. Here, we develop a ''third-generation IL-2'' that combines site-specific targeting and bifunctionality. We generated a bivalent fusion protein linking IL-2 to a single-chain antibody recognizing oxidation-specific epitopes (OSEs), which are abundantly expressed at inflamed sites. Targeting OSEs provides not only site-specific localization, but also true bifunctionality as both anti-OSE antibodies and IL-2LD independently show therapeutic benefit in limiting inflammation. We first show that IL-2IT has bifunctional biological activities in vitro. In vivo, IL-2IT had increased specificity for Treg over Teff activation, which we attribute to a conformation-dependent modulation of IL-2 receptor engagement. Importantly, IL-2IT provided precise delivery to inflamed tissues in models of psoriasis and colitis. Altogether, this resulted in superior therapeutic benefit in multiple clinical settings, including in atherosclerosis models. Thus, our strategy illustrates a generalizable approach to cytokine engineering that preserves native signaling while achieving spatial control. Specifically, our findings validate OSE targeting as an efficient strategy to guide therapeutics to sites of inflammation and establish OSE-IL-2 as a promising bispecific Treg engager for treating inflammation.

immunology↗

Structural and biophysical characterisation of ubiquitin variants that specifically inhibit the ubiquitin conjugating enzyme Ube2d2

The ubiquitin conjugating E2 enzymes play a central role in ubiquitin transfer. Disruptions to the ubiquitin system are implicated in multiple diseases and as a result, molecules that modulate the activity of the ubiquitin system are of interest. E2 enzyme function is reliant on interactions with partner proteins and disruption of these is an effective way of modulating activity. Here, we report the discovery of ubiquitin variants (UbVs) that inhibit the E2 enzyme, Ube2d2 (UbcH5b). The six UbVs identified inhibit ubiquitin chain building, and structural and biophysical characterisation of two of these demonstrate they bind to Ube2d2 with low micromolar affinity and high specificity within the Ube2d family of E2 enzymes. Both characterised UbVs bind at a site that overlaps with E1 binding, while the more inhibitory UbV blocks a critical non-covalent ubiquitin binding site on the E2 enzyme. The discovery of novel protein-based ubiquitin derivatives that inhibit protein-protein interactions is an important step towards discovery of small molecules that inhibit the activity of E2 enzymes. Furthermore, the specificity of the UbVs within the Ube2d family suggests that it may be possible to develop tools to selectively inhibit highly related E2 enzymes.

biochemistry↗

Multifaceted N-degron recognition and ubiquitylation by GID/CTLH E3 ligases

N-degron E3 ubiquitin ligases recognize specific residues at the N-termini of substrates. Although molecular details of N-degron recognition are known for several E3 ligases, the range of N-terminal motifs that can bind a given E3 substrate binding domain remains unclear. Here, studying the Gid4 and Gid10 substrate receptor subunits of yeast "GID"/human "CTLH" multiprotein E3 ligases, whose known substrates bear N-terminal prolines, we discovered capacity for high-affinity binding to diverse N-terminal sequences determined in part by context. Screening of phage displaying peptide libraries with exposed N-termini identified novel consensus motifs with non-Pro N-terminal residues distinctly binding Gid4 or Gid10 with high affinity. Structural data reveal that flexible loops in Gid4 and Gid10 conform to complementary folds of diverse interacting peptide sequences. Together with analysis of endogenous substrate degrons, the data show that degron identity, substrate domains harboring targeted lysines, and varying E3 ligase higher-order assemblies combinatorially determine efficiency of ubiquitylation and degradation.

biochemistry↗

Identification of ubiquitin variants that inhibit the E2 ubiquitin conjugating enzyme, Ube2k

Transfer of ubiquitin to substrate proteins regulates most processes in eukaryotic cells. E2 enzymes are a central component of the ubiquitin machinery, and generally determine the type of ubiquitin signal generated and thus the ultimate fate of substrate proteins. The E2, Ube2k, specifically builds degradative ubiquitin chains on diverse substrates. Here we have identified protein-based reagents, called ubiquitin variants (UbVs), that bind tightly and specifically to Ube2k. Crystal structures reveal that the UbVs bind to the E2 enzyme at a hydrophobic cleft that is distinct from the active site and previously identified ubiquitin binding sites. We demonstrate that the UbVs are potent inhibitors of Ube2k and block both ubiquitin charging of the E2 enzyme, and E3-catalysed ubiquitin transfer. The binding site of the UbVs suggests they directly clash with the ubiquitin activating enzyme, while potentially disrupting interactions with E3 ligases via allosteric effects. Our data reveal the first protein-based inhibitors of Ube2k and unveil a hydrophobic groove that could be an effective target for inhibiting Ube2k and other E2 enzymes.

biochemistry↗

Protein structure from experimental evolution

Natural evolution encodes rich information about the structure and function of biomolecules in the genetic record. Previously, statistical analysis of co-variation patterns in natural protein families has enabled the accurate computation of 3D structures. Here, we explored whether similar information can be generated by laboratory evolution, starting from a single gene and performing multiple cycles of mutagenesis and functional selection. We evolved two bacterial antibiotic resistance proteins, {beta}-lactamase PSE1 and acetyltransferase AAC6, and obtained hundreds of thousands of diverse functional sequences. Using evolutionary coupling analysis, we inferred residue interactions in good agreement with contacts in the crystal structures, confirming genetic encoding of structural constraints in the selected sequences. Computational protein folding with contact constraints yielded 3D structures with the same fold as that of natural relatives. Evolution experiments combined with inference of residue interactions from sequence information opens the door to a new experimental method for the determination of protein structures.

evolutionary biology↗