How aberrant N-glycosylation can alter protein functionality and ligand binding: An atomistic view

Protein-assembly defects due to an enrichment of aberrant conformational protein variants are emerging as a new frontier in therapeutics design. Understanding the structural elements that rewire the conformational dynamics of proteins and pathologically perturb functionally oriented ensembles is important for inhibitor development. Chaperones are hub proteins for the assembly of multiprotein complexes and an enrichment of aberrant conformers can affect the cellular proteome, and in turn, phenotypes. Here, we integrate computational and experimental tools to investigte how N-glycosylation of specific residues in glucose-regulated protein 94 (GRP94) modulates internal dynamics and alters the conformational fitness of regions fundamental for the interaction with ATP and synthetic ligands and impacts substructures important for the recognition of interacting proteins. N-glycosylation plays an active role in modulating the energy landscape of GRP94, and we provide support for leveraging the knowledge on distinct glycosylation variants to design molecules targeting GRP94 disease-associated conformational states and assemblies. [Display omitted] •N-glycosylation and ligands actively modify functional dynamics of the chaperone GRP94•Dynamic mechanisms favor GRP94 transition from a folder to a scaffolding protein•Dynamic GRP94 mechanisms rationalize the biological activity of small molecules•Pathologically N-glycosylated GRP94 variants are selectively actionable Castelli et al. describe at atomic resolution how the glycosylation of the chaperone GRP94, an important protein for cell life control, impacts on its functional spectrum remodeling interaction networks and affects disease phenotypes. The results are actionable in the selection of drugs that specifically target disease-related forms of GRP94.