Biology subjects

Lenaerts, A.-S.

Publications and source records attributed to Lenaerts, A.-S..

3 recordsLinked to original sources

bioRxiv2025

EndoNB: A general strategy to study the internalization of cell surface proteins

The cell surface harbors thousands of distinct proteins whose function depend on continuous cycles of internalization and replenishment. Disturbances in this turnover are typical hallmarks of many diseases. Yet, tools to study the dynamics of most surface proteins are suboptimal or unavailable. Here, we present a new method that enables the analysis of surface protein turnover of virtually any surface protein at endogenous levels. Our approach combines CRISPR/cas9-mediated genome engineering with a cleavable recombinant probe, which addresses many of the shortcomings of current methodologies. We demonstrate the capabilities our method by studying the internalization behavior of a previously uncharacterized surface protein and by assessing the effect of ligands and activity modulators in the endocytic behavior of established receptors. In summary, our method represents a versatile strategy to explore surface protein biology and enhances our ability to study the mechanisms of membrane protein retrieval and recycling.

cell biology↗

bioRxiv2023

Cardiac glycosides restore autophagy flux in an iPSC-derived neuronal model of WDR45 deficiency

Beta-Propeller Protein-Associated Neurodegeneration (BPAN) is one of the commonest forms of Neurodegeneration with Brain Iron Accumulation, caused by mutations in the gene encoding the autophagy-related protein, WDR45. The mechanisms linking autophagy, iron overload and neurodegeneration in BPAN are poorly understood and, as a result, there are currently no disease-modifying treatments for this progressive disorder. We have developed a patient-derived, induced pluripotent stem cell (iPSC)-based midbrain dopaminergic neuronal cell model of BPAN (3 patient, 2 age-matched controls and 2 isogenic control lines) which shows defective autophagy and aberrant gene expression in key neurodegenerative, neurodevelopmental and collagen pathways. A high content imaging-based medium-throughput blinded drug screen using the FDA-approved Prestwick library identified 5 cardiac glycosides that both corrected disease-related defective autophagosome formation and restored BPAN-specific gene expression profiles. Our findings have clear translational potential and emphasise the utility of iPSC-based modelling in elucidating disease pathophysiology and identifying targeted therapeutics for early-onset monogenic disorders.

cell biology↗

bioRxiv2022

Flat Clathrin Lattices Nucleate Reticular Adhesions in an Integrin β1 Activity-Dependent Manner

Reticular adhesions (RAs) consist of integrin v{beta}5 and harbor flat clathrin lattices (FCLs), long-lasting structures with similar molecular composition to clathrin mediated endocytosis (CME) carriers. Why FCLs and RAs colocalize is not known. Here, we show that FCLs assemble RAs in a process controlled by fibronectin (FN) and its receptor, integrin v{beta}5. We observed that cells on FN-rich matrices displayed fewer FCLs and RAs. CME machinery inhibition abolished RAs and live-cell imaging showed that RA establishment requires FCL co-assembly. The inhibitory activity of FN was mediated by the activation of integrin 5{beta}1 at Tensin1-positive fibrillar adhesions. Conventionally, endocytosis disassembles cellular adhesions by internalization of their components. Our results present a novel paradigm in the relationship between these two processes by showing that endocytic proteins can actively function in the assembly of cell adhesions. Furthermore, we show this novel adhesion assembly mechanism is coupled to cell migration via a unique crosstalk between cell matrix adhesions.

cell biology↗