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Huyghe, A.

Publications and source records attributed to Huyghe, A..

4 recordsLinked to original sources

Generative design of intrinsically disordered proteins based on conditioned protein language models: Data is the limit

Intrinsically disordered proteins and regions (IDRs) are central to a multitude of biological processes. Despite extensive studies of their structural and physicochemical properties, the rational design of IDRs with defined conformational behavior remains challenging due to their ensemble nature. Here we present a generative framework for designing disordered protein sequences conditioned on target conformational ensemble descriptors using protein language models (pLMs). We formulate IDR design as the task of generating amino acid sequences predicted to realize specified biophysical properties and implement a Transformer encoder-decoder architecture that maps numerical descriptors to protein sequences. By training models on datasets spanning two orders of magnitude in size, we show that accurate control of conformational and physicochemical properties is achieved only at large data scale. These results demonstrate the feasibility of conditioning generative models on ensemble-level descriptors for IDR design. More broadly, these results support a data-centric paradigm for protein engineering, in which data availability emerges as a key limiting factor for the accurate design of IDRs.

bioinformatics↗

A ligand/receptor trafficking clock governs self-renewal and abscission dynamics in pluripotent stem cells

Summary/AbstractHow extracellular cues are temporally integrated to regulate self-renewal and differentiation propensities across the cell cycle remains largely unresolved. We identify a ligand/receptor trafficking clock in rodent and human pluripotent stem cells (PSCs) in which the cyclic turnover of Netrin-1 and its receptors Neo1 and Unc5b (NNU) governs self-renewal capacity and abscission dynamics. In G1, NNU complexes undergo Clathrin-mediated internalization and lysosomal degradation, a process required for timely post-mitotic bridge abscission. At later stages of the cycle, NNU activate Src within early endosomes, inducing a genome-wide redistribution of the transcriptional co-activator Yap1. This reshapes gene regulatory networks by activating stemness- and ectoderm-associated transcriptional programs enriched for Sox2/Nanog binding and by repressing mesodermal- and cell cycle-related targets enriched for Sox2 and Tcf3. Functionally, recombinant Netrin-1 reduces functional heterogeneity and enhances clonogenicity in G1, uncovering a tractable strategy to canalize stem cell behavior. Collectively, our results reveal cell cycle-dependent ligand/receptor trafficking as a temporal clock that directly links membrane dynamics to epigenetic regulation and stem cell fate, opening new avenues for regenerative medicine.

cell biology↗

The Pioneer Transcription Factor Oct4 Differentially Co-opts Bcl11a and Bcl11b to Regulate Reprogramming to Pluripotency

Pioneer transcription factors (TFs) orchestrate development, reprogramming, and cancer. Yet, the molecular mechanisms by which they cooperate with endogenous TFs and chromatin to trigger cell fate conversions remain largely unknown. Here, we identified antagonistic functions in reprogramming to pluripotency for the two paralogous somatic zinc finger TFs Bcl11a and Bcl11b. We reveal that Bcl11a and Bcl11b are initially co-expressed in mouse embryonic fibroblasts and then segregate in cellular intermediates respectively prone or refractory to reprogramming, transdifferentiation, and oncogenic transformation. They exert opposite functions - with Bcl11a promoting and Bcl11b hindering - the efficacy of induced pluripotent stem cells generation. During reprogramming, we uncover that Bcl11b safeguards cellular identity by persistently binding to differentiation genes with Runx1 in refractory intermediates. In contrast, in reprogramming intermediates, Bcl11a interacts with Oct4 and is initially displaced from MEF enhancers. Bcl11a then binds transiently and contributes to activate the E3 ubiquitin ligase Pja1 that regulates Smad3, thus promoting mesenchymal-epithelial transition and constraining senescence. Collectively, our work unveils how the differential repurposing of paralogous TFs by Oct4 orchestrates reprogramming to pluripotency.

cell biology↗

The comprehensive roadmaps of reprogramming and transformation unveiled antagonistic roles for bHLH transcription factors in the control of cellular plasticity

Coordinated changes of cellular identity and plasticity are critical for pluripotent reprogramming (PR) and malignant transformation (MT). However, the molecular circuitries orchestrating these modifications, as well as their degree of analogy during reprogramming and transformation, remain unknown. To address this question, we generated "repro-transformable" mice models and dissected comparatively the early events underpinning PR - mediated by Oct4, Sox2, Klf4, c-Myc - and MT - triggered by oncogenic Ras and c-Myc. Transcriptomic analyses allowed the identification of a unique set of markers - the cell surface glycoprotein Thy1 and the transcription factor (TF) Bcl11b - that are commonly downregulated during PR and MT and delineate cellular intermediates (CI) highly amenable to generate pluripotent or malignant derivatives. Comprehensive transcriptomic, epigenomic and functional analyses of different CI, prone or refractory to PR/MT, unveiled that cellular plasticity acquisition precedes the broad extinction of cellular identity. It also demonstrated the existence of specific and shared molecular features of PR and MT while ensuring the identification of broad-range regulators of cellular plasticity. As a proof-of-concept, we revealed that the basic helix-loop-helix (bHLH) class A TF Atoh8 constrains rodent and human iPS cells generation as well as MT and direct neuron conversion. Mechanistically, this TF hampers the reactivation of the pluripotent network during PR and limits the acquisition of phenotypic plasticity during MT. Furthermore, an integrated analysis of Atoh8 genome-wide binding, alongside the other bHLH TFs c-Myc, Ascl1 and MyoD promoting reprogramming/transdifferentiation, unveiled how Atoh8 constrains cellular plasticity by occupying a specific subset of MEF enhancers and by finetuning WNT signalling activity. Collectively, by deconvoluting the early steps of the reprogramming and transformation roadmaps, this integrated study uncoupled changes of cellular plasticity and identity to shed light on novel insights into reprogramming and cancer biology. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=161 SRC="FIGDIR/small/424606v1_ufig1.gif" ALT="Figure 1"> View larger version (35K): org.highwire.dtl.DTLVardef@1718383org.highwire.dtl.DTLVardef@1714ab8org.highwire.dtl.DTLVardef@e0958borg.highwire.dtl.DTLVardef@7a0643_HPS_FORMAT_FIGEXP M_FIG C_FIG One-sentence summaryComparative roadmaps of cellular plasticity acquisition during pluripotent reprogramming and malignant transformation.

cell biology↗