alpha-Synuclein filaments bind the transcriptional regulator HMGB-1.

Abnormal accumulation of alpha-synuclein filaments in Lewy bodies is a neuropathological hallmark of Parkinson's disease and sequestration of cellular protein into these protein aggregates may contribute to the degenerative process. We identified the transcriptional co-factor high mobility group protein 1 (HMGB-1) as a ligand for alpha-synuclein filaments by a filament spin-down technique, mass spectrometric peptide mapping and immunoblotting. HMGB-1 binds preferentially to aggregated alpha-synuclein and is present in alpha-synuclein filament-containing Lewy bodies isolated from brain tissue affected with dementia with Lewy bodies or Parkinson's disease. Our results demonstrate that alpha-synuclein filaments hold the potential for disturbing the cellular gene expression as they can sequester a component involved in cellular transcription regulation.