Identification of protein interfaces between α-synuclein, the principal component of Lewy bodies in Parkinson disease, and the molecular chaperones human Hsc70 and the yeast Ssa1p

J Biol Chem. 2012 Sep 21;287(39):32630-9. doi: 10.1074/jbc.M112.387530. Epub 2012 Jul 26.

Abstract

Fibrillar α-synuclein (α-Syn) is the principal component of Lewy bodies, which are evident in individuals affected by Parkinson disease (PD). This neuropathologic form of α-Syn plays a central role in PD progression as it has been shown to propagate between neurons. Tools that interfere with α-Syn assembly or change the physicochemical properties of the fibrils have potential therapeutic properties as they may be sufficient to interfere with and/or halt cell-to-cell transmission and the systematic spread of α-Syn assemblies within the central nervous system. Vertebrate molecular chaperones from the constitutive/heat-inducible heat shock protein 70 (Hsc/p70) family have been shown to hinder the assembly of soluble α-Syn into fibrils and to bind to the fibrils and very significantly reduce their toxicity. To understand how Hsc70 family members sequester soluble α-Syn, we set up experiments to identify the molecular chaperone-α-Syn surface interfaces. We cross-linked human Hsc70 and its yeast homologue Ssa1p and α-Syn using a chemical cross-linker and mapped the Hsc70- and Ssa1p-α-Syn interface. We show that the client binding domain of Hsc70 and Ssa1p binds two regions within α-Syn similar to a tweezer, with the first spanning residues 10-45 and the second spanning residues 97-102. Our findings define what is necessary and sufficient for engineering Hsc70- and Ssa1p-derived polypeptide with minichaperone properties with a potential as therapeutic agents in Parkinson disease through their ability to affect α-Syn assembly and/or toxicity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • HSC70 Heat-Shock Proteins / chemistry
  • HSC70 Heat-Shock Proteins / genetics
  • HSC70 Heat-Shock Proteins / metabolism*
  • HSP70 Heat-Shock Proteins / chemistry
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • Humans
  • Lewy Bodies / chemistry
  • Lewy Bodies / genetics
  • Lewy Bodies / metabolism*
  • Parkinson Disease / drug therapy
  • Parkinson Disease / genetics
  • Parkinson Disease / metabolism*
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / metabolism
  • Peptides / therapeutic use
  • Protein Binding
  • Protein Engineering / methods
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae / chemistry
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Solubility
  • alpha-Synuclein / chemistry
  • alpha-Synuclein / genetics
  • alpha-Synuclein / metabolism*

Substances

  • HSC70 Heat-Shock Proteins
  • HSP70 Heat-Shock Proteins
  • HSPA8 protein, human
  • Peptides
  • SNCA protein, human
  • Saccharomyces cerevisiae Proteins
  • alpha-Synuclein
  • Adenosine Triphosphatases
  • SSA1 protein, S cerevisiae