The ABCA1 Q597R mutant undergoes trafficking from the ER upon ER stress

Biochem Biophys Res Commun. 2008 May 16;369(4):1174-8. doi: 10.1016/j.bbrc.2008.03.018. Epub 2008 Mar 14.

Abstract

Mutations in ATP binding cassette transporter 1 (ABCA1), a membrane protein associated with cellular cholesterol efflux, cause Tangier disease (TD). Previously, we showed that an ABCA1 Q597R mutant (QR) identified in TD is retained in the endoplasmic reticulum. Here, we report that QR trafficking to the plasma membrane was rapidly induced by thapsigargin or DTT, indicating that ER stress-induced QR trafficking. However, pharmacological rescue of ABCA1 activity was not observed. The trafficking was dependent on COPII components and occurred via the ER-Golgi intermediate compartments. Furthermore, we found that QR was more sensitive to ER stress than ATF6, a transcription factor associated with the ER stress response. These results suggest that thapsigargin can be effective in correcting trafficking defects, and raise the possibility that ER stress-induced trafficking is involved in ER quality control.

MeSH terms

  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters / genetics*
  • ATP-Binding Cassette Transporters / metabolism*
  • Activating Transcription Factor 6 / metabolism
  • Amino Acid Substitution
  • Arginine / chemistry
  • Arginine / genetics
  • Biological Transport / drug effects
  • Cell Membrane / drug effects
  • Cell Membrane / metabolism*
  • Cholesterol / metabolism
  • Endoplasmic Reticulum / drug effects*
  • Endoplasmic Reticulum / metabolism*
  • Enzyme Inhibitors / pharmacology
  • Glutamine / chemistry
  • Glutamine / genetics
  • Golgi Apparatus / metabolism
  • Humans
  • Mutation
  • Protein Transport / drug effects
  • Protein Transport / genetics
  • Tangier Disease / genetics
  • Tangier Disease / metabolism
  • Thapsigargin / pharmacology*

Substances

  • ABCA1 protein, human
  • ATF6 protein, human
  • ATP Binding Cassette Transporter 1
  • ATP-Binding Cassette Transporters
  • Activating Transcription Factor 6
  • Enzyme Inhibitors
  • Glutamine
  • Thapsigargin
  • Arginine
  • Cholesterol