Biology subjects

Gilquin, L.

Publications and source records attributed to Gilquin, L..

3 recordsLinked to original sources

bioRxiv2025

Characterizing drug activity with sensitive interactomes in human living cells

A number of human diseases results from abnormal protein-protein interactions (PPIs) involving key regulatory proteins. Therefore, an important strategy in therapeutics consists in developing inhibitory molecules that should ideally be specific for the aberrant PPI. In this context, it is critical to evaluate the number of PPIs that could be affected by the candidate molecule and to analyze the inhibitory potential before and after the formation of the PPI. Surprisingly, these two molecular aspects are rarely considered, due to a lack of appropriate methodological approaches. In this study, we present a novel methodology that captures drug-sensitive PPIs by considering drug-induced cellular functions in live cell conditions. As a proof-of-concept, we identified interactions of the human core signaling protein ERK1 that are specifically affected by two different inhibitory molecules. In addition, we used a complementary set of innovative tools that allowed visualizing the inhibitory effect on ERK1/cofactor protein complexes after their assembly in living cells. Overall, our work establishes a unique methodological approach for deciphering drug activity for potentially any target bait protein of interest.

molecular biology↗

bioRxiv2024

A nanobody-based approach to capture and visualize interactions of binary protein complexes in living cells

Protein interaction networks (or interactomes) are formed progressively, each interaction influencing the next one. Accordingly, a same protein will establish different interactomes depending on its first associated cofactor, thereby diversifying its function in the cell. In contrast to their central role, few methods exist to capture interactomes of dimeric protein complexes. Here, we tackle this issue by introducing an innovative method based on bimolecular fluorescence complementation and the specific binding of a nanobody fused to a proximity-dependent biotinylating enzyme. This method was applied to visualize and capture specific interactions of the cytoplasmic TAZ/14-3-3e and nuclear TAZ/TEAD2 complexes, which are major downstream effectors of the Hippo signaling pathway. Among other interactions, we identified SERPINB4 as a novel regulator of TAZ and 14-3-3e proliferative activity in mesenchymal stromal cells. Molecular dissections in living cells revealed the central role of a unique residue of TAZ for recruiting SERPINB4 specifically in the presence of 14-3-3e. Overall, our work demonstrates the importance of considering binary protein complexes for deciphering interactomes and establishes a novel sensitive method in this perspective.

molecular biology↗

bioRxiv2023

Dual-topology of collagen XV and tenascin C acts in concert to guide and shape developing motor axons

During development, motor axons are guided towards their muscle target by various extrinsic cues including extracellular matrix (ECM) proteins those identities remain poorly documented. Using single-cell RNA-sequencing of differentiating slow muscle progenitors (SMP) in zebrafish, we charaterized the SMP as a major source of ECM proteins that were computationally predicted to form a basement membrane-like structure tailored for motor axon guidance. Multiple in vivo and in vitro approaches further revealed that motor axon shape and growth relies on the timely expression of the attractive cue Collagen XV-B (ColXV-B) that locally provides motor axons with a permissive soft microenvironment and separately organizes the repulsive cue Tenascin C into a unique functional dual topology. Bioprinted micropatterns mimicking their unique topology provide compelling evidence that it represents a sufficient condition to elicit directional motor axon growth. Our study provides the first evidence that ECM topology and stiffness critically influence motor axon navigation in vertebrates with potential applications in regenerative medicine for peripheral nerve injury.

developmental biology↗