Subject area	Biology
More specific subject area	Proteomic, Neurobiology, Neurodegenerative diseases
Type of data	Mass spectrometry data and tables with identified protein.
How data was acquired	Tryptic peptides were analyzed by nanoLC-MS/MS using an EASY-nLC HPLC system (Proxeon, Thermo) coupled to a LTQ-Orbitrap-velos (Thermo) mass spectrometer. Data acquisitions were conducted in the data-dependent acquisition mode.
Data format	.Raw files from the instrument, .dat peak list files, .mzid identification result files using MASCOT
Experimental factors	Cultured primary cortical neurons and astrocytes were exposed for 10 min to oligomeric or fibrillar S-tagged a-syn.
Experimental features	Neuronal or astrocyte partner proteins of a-syn oligomers and fibrils were purified with the a-syn assemblies on S-protein agarose beads. Proteins were digested on S-protein agarose beads using trypsin. Tryptic peptides were analyzed by nanoLC-MS/MS. Proteins were identified in the SwissProt database with MASCOT. Proteins interacting selectively with a-syn assemblies were identified by comparison to controls neurons and astrocytes that were not exposed to a-syn assemblies.
Data source location	Neuroscience Institute of Paris-Saclay, “Protein misfolding and aggregation in Neurodegenerative Diseases” team, CNRS, Gif-sur-Yvette, France.
Data accessibility	Data are within this article. The mass spectrometry proteomic data (neurons and astrocytes) have been deposited to the ProteomeXchange Consortium via the PRIDE partner repository with the dataset identifiers PRIDE: PXD002256 to PRIDE: PXD002263 and DOI 10.6019/PXD002256 to 10.6019/PXD002263. The list of identified proteins are presented inSupplementary Tables 1–4.