Conformational dynamics of free and membrane-bound human Hsp70 in model cytosolic and endo-lysosomal environments.
Valeria CalvaresiLine T TruelsenSidsel B LarsenNikolaj H T PetersenThomas KirkegaardKasper Dyrberg RandPublished in: Communications biology (2021)
The binding of the major stress-inducible human 70-kDa heat shock protein (Hsp70) to the anionic phospholipid bis-(monoacylglycero)-phosphate (BMP) in the lysosomal membrane is crucial for its impact on cellular pathology in lysosomal storage disorders. However, the conformational features of this protein-lipid complex remain unclear. Here, we apply hydrogen-deuterium exchange mass spectrometry (HDX-MS) to describe the dynamics of the full-length Hsp70 in the cytosol and its conformational changes upon translocation into lysosomes. Using wild-type and W90F mutant proteins, we also map and discriminate the interaction of Hsp70 with BMP and other lipid components of the lysosomal membrane. We identify the N-terminal of the nucleotide binding domain (residues 87-118) as the primary orchestrator of BMP interaction. We show that the conformation of this domain is significantly reorganized in the W90F mutant, explaining its inability to stabilize lysosomal membranes. Overall, our results reveal important new molecular details of the protective effect of Hsp70 in lysosomal storage diseases, which, in turn, could guide future drug development.
Keyphrases
- heat shock protein
- wild type
- heat shock
- mass spectrometry
- molecular dynamics simulations
- endothelial cells
- molecular dynamics
- single molecule
- mesenchymal stem cells
- heat stress
- fatty acid
- multiple sclerosis
- induced pluripotent stem cells
- bone regeneration
- high resolution
- gene expression
- transcription factor
- living cells
- ms ms
- amino acid
- single cell
- fluorescent probe
- high performance liquid chromatography
- dna methylation
- capillary electrophoresis
- current status
- gas chromatography
- stress induced