Aggresome-like structure induced by isothiocyanates is novel proteasome-dependent degradation machinery

Biochem Biophys Res Commun. 2009 Oct 16;388(2):456-62. doi: 10.1016/j.bbrc.2009.08.047. Epub 2009 Aug 12.

Abstract

Unwanted or misfolded proteins are either refolded by chaperones or degraded by the ubiquitin-proteasome system (UPS). When UPS is impaired, misfolded proteins form aggregates, which are transported along microtubules by motor protein dynein towards the juxta-nuclear microtubule-organizing center to form aggresome, a single cellular garbage disposal complex. Because aggresome formation results from proteasome failure, aggresome components are degraded through the autophagy/lysosome pathway. Here we report that small molecule isothiocyanates (ITCs) can induce formation of aggresome-like structure (ALS) through covalent modification of cytoplasmic alpha- and beta-tubulin. The formation of ALS is related to neither proteasome inhibition nor oxidative stress. ITC-induced ALS is a proteasome-dependent assembly for emergent removal of misfolded proteins, suggesting that the cell may have a previously unknown strategy to cope with misfolded proteins.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Anticarcinogenic Agents / pharmacology*
  • Biomarkers
  • Cytoplasm / metabolism
  • HeLa Cells
  • Humans
  • Isothiocyanates / pharmacology*
  • Proteasome Endopeptidase Complex / drug effects*
  • Proteasome Endopeptidase Complex / metabolism
  • Protein Folding
  • Sulfoxides
  • Thiocyanates / pharmacology*
  • Tubulin / metabolism*

Substances

  • Anticarcinogenic Agents
  • Biomarkers
  • Isothiocyanates
  • Sulfoxides
  • Thiocyanates
  • Tubulin
  • phenethyl isothiocyanate
  • benzyl isothiocyanate
  • Proteasome Endopeptidase Complex
  • sulforaphane