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Metabolite annotation from imaging mass spectrometry (imaging MS) data is a difficult undertaking that is extremely resource intensive. Here, we adapted METASPACE, cloud software for imaging MS metabolite annotation and data interpretation, to quickly annotate microbial specialized metabolites from high-resolution and high-mass accuracy imaging MS data. Compared with manual ion image and MS1 annotation, METASPACE is faster and, with the appropriate database, more accurate. We applied it to data from microbial colonies grown on agar containing 10 diverse bacterial species and showed that METASPACE was able to annotate 53 ions corresponding to 32 different microbial metabolites. This demonstrates METASPACE to be a useful tool to annotate the chemistry and metabolic exchange factors found in microbial interactions, thereby elucidating the functions of these molecules. ispartof: METABOLITES vol:11 issue:8 ispartof: location:Switzerland status: published

Clathrin is a unique scaffold protein, which forms polyhedral lattices with flat and curved morphology. The function of curved clathrin-coated pits in forming endocytic structures is well studied. On the contrary, the role of large flat clathrin arrays, called clathrin-coated plaques, remains ambiguous. Previous studies suggested an involvement of plaques in cell adhesion. However, the molecular origin leading to their formation and their precise functions remain to be determined. Here, we study the origin and function of clathrin-coated plaques during cell migration. We revealed that plaque formation is intimately linked to extracellular matrix (ECM) modification by focal adhesions (FAs). We show that in migrating cells, FAs digest the ECM creating extracellular topographical cues that dictate the future location of clathrin-coated plaques. We identify Eps15 and Eps15R as key regulators for the formation of clathrin-coated plaques at locally remodelled ECM sites. Using a genetic silencing approach to abrogate plaque formation and 3D-micropatterns to spatially control the location of clathrin-coated plaques, we could directly correlate cell migration directionality with the formation of clathrin-coated plaques and their ability to recognize extracellular topographical cues. We here define the molecular mechanism regulating the functional interplay between FAs and plaques and propose that clathrin-coated plaques act as regulators of cell migration promoting contact guidance-mediated collective migration in a cell-to-cell contact independent manner.