Aggresomes formed by alpha-synuclein and synphilin-1 are cytoprotective

J Biol Chem. 2004 Feb 6;279(6):4625-31. doi: 10.1074/jbc.M310994200. Epub 2003 Nov 19.


Lewy bodies (LBs), which are the hallmark pathologic features of Parkinson's disease and of dementia with LBs, have several morphologic and molecular similarities to aggresomes. Whether such cytoplasmic inclusions contribute to neuronal death or protect cells from the toxic effects of misfolded proteins remains controversial. In this report, the role of aggresomes in cell viability was addressed in the context of over-expressing alpha-synuclein and its interacting partner synphilin-1 using engineered 293T cells. Inhibition of proteasome activity elicited the formation of juxtanuclear aggregates with characteristics of aggresomes including immunoreactivity for vimentin, gamma-tubulin, ubiquitin, proteasome subunit, and hsp70. As expected from the properties of aggresomes, the microtubule disrupting agents, vinblastin and nocodazole, markedly prevented the formation of these inclusions. Similar to LBs, the phosphorylated form of alpha-synuclein co-localized in these synphilin-1-containing aggresomes. Although the caspase inhibitor z-VAD-fmk significantly reduced the number of apoptotic cells, it had no impact on the percentage of aggresome-positive cells. Finally, quantitative analysis revealed aggresomes in 60% of nonapoptotic cells but only in 10% of apoptotic cells. Additionally, alpha-synuclein-induced apoptosis was not coupled with increased prevalence of aggresome-bearing cells. Taken together, these observations indicate a disconnection between aggresome formation and apoptosis, and support a protective role for these inclusions from the toxicity associated with the combined over-expression of alpha-synuclein and synphilin-1.

MeSH terms

  • Amino Acid Chloromethyl Ketones / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / physiology
  • Carrier Proteins / chemistry*
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line
  • Cell Survival
  • Cysteine Proteinase Inhibitors / pharmacology
  • Humans
  • Inclusion Bodies / drug effects
  • Inclusion Bodies / metabolism*
  • Lewy Bodies / metabolism
  • Lewy Body Disease / metabolism
  • Lewy Body Disease / pathology
  • Macromolecular Substances
  • Microtubules / drug effects
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism*
  • Neurons / drug effects
  • Neurons / metabolism
  • Neurons / pathology
  • Neuroprotective Agents / pharmacology
  • Nocodazole / pharmacology
  • Parkinson Disease / metabolism
  • Parkinson Disease / pathology
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Synucleins
  • Transfection
  • Vinblastine / pharmacology
  • alpha-Synuclein


  • Amino Acid Chloromethyl Ketones
  • Carrier Proteins
  • Cysteine Proteinase Inhibitors
  • Macromolecular Substances
  • Nerve Tissue Proteins
  • Neuroprotective Agents
  • Recombinant Proteins
  • SNCA protein, human
  • SNCAIP protein, human
  • Synucleins
  • alpha-Synuclein
  • benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone
  • Vinblastine
  • Nocodazole