Trivalent arsenic inhibits the functions of chaperonin complex

Genetics. 2010 Oct;186(2):725-34. doi: 10.1534/genetics.110.117655. Epub 2010 Jul 26.

Abstract

The exact molecular mechanisms by which the environmental pollutant arsenic works in biological systems are not completely understood. Using an unbiased chemogenomics approach in Saccharomyces cerevisiae, we found that mutants of the chaperonin complex TRiC and the functionally related prefoldin complex are all hypersensitive to arsenic compared to a wild-type strain. In contrast, mutants with impaired ribosome functions were highly arsenic resistant. These observations led us to hypothesize that arsenic might inhibit TRiC function, required for folding of actin, tubulin, and other proteins postsynthesis. Consistent with this hypothesis, we found that arsenic treatment distorted morphology of both actin and microtubule filaments. Moreover, arsenic impaired substrate folding by both bovine and archaeal TRiC complexes in vitro. These results together indicate that TRiC is a conserved target of arsenic inhibition in various biological systems.

Publication types

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

MeSH terms

  • Actins / chemistry
  • Actins / metabolism
  • Arsenic Trioxide
  • Arsenicals
  • Blotting, Western
  • Chaperonin Containing TCP-1 / antagonists & inhibitors*
  • Chaperonin Containing TCP-1 / chemistry
  • Chaperonin Containing TCP-1 / metabolism
  • Fluorescent Antibody Technique
  • Methanococcus / drug effects
  • Microtubule Proteins
  • Microtubules / drug effects
  • Microtubules / metabolism
  • Molecular Chaperones / antagonists & inhibitors
  • Molecular Chaperones / chemistry
  • Mutation
  • Oxides / toxicity*
  • Protein Folding
  • Saccharomyces cerevisiae / drug effects*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / antagonists & inhibitors*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism
  • Tubulin / chemistry
  • Tubulin / metabolism

Substances

  • Actins
  • Arsenicals
  • Microtubule Proteins
  • Molecular Chaperones
  • Oxides
  • Saccharomyces cerevisiae Proteins
  • Tubulin
  • prefoldin
  • Chaperonin Containing TCP-1
  • Arsenic Trioxide