A chimeric mutant analysis in yeast cells suggests BiP independent regulation of the mammalian endoplasmic reticulum-stress sensor IRE1α

Biosci Biotechnol Biochem. 2018 Sep;82(9):1527-1530. doi: 10.1080/09168451.2018.1478716. Epub 2018 May 28.

Abstract

An endoplasmic reticulum (ER)-located transmembrane protein, Ire1, triggers cytoprotective events upon ER stress. Chimeric yeast Ire1 carrying the luminal domain of the mammalian major Ire1 paralogue IRE1α is upregulated in ER-stressed yeast cells, but is poorly associated with the ER-located chaperone BiP even under non-stressed conditions. This observation contradicts the theory that BiP is the master regulator of IRE1α.

Keywords: molecular chaperone; organelle; stress response; stress sensing; unfolded protein response.

MeSH terms

  • Basic-Leucine Zipper Transcription Factors / genetics
  • Endoplasmic Reticulum Stress*
  • Endoribonucleases / metabolism*
  • Fungal Proteins / genetics*
  • Green Fluorescent Proteins / genetics
  • HSP70 Heat-Shock Proteins / genetics*
  • Humans
  • Microscopy, Fluorescence
  • Mutant Chimeric Proteins / genetics*
  • Mutation*
  • Plasmids
  • Protein Serine-Threonine Kinases / metabolism*
  • RNA Splicing
  • RNA, Messenger / genetics
  • Repressor Proteins / genetics
  • Reverse Transcriptase Polymerase Chain Reaction
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / genetics
  • Unfolded Protein Response

Substances

  • Basic-Leucine Zipper Transcription Factors
  • Fungal Proteins
  • HAC1 protein, S cerevisiae
  • HSP70 Heat-Shock Proteins
  • KAR2 protein, yeast
  • Mutant Chimeric Proteins
  • RNA, Messenger
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Green Fluorescent Proteins
  • ERN1 protein, human
  • Protein Serine-Threonine Kinases
  • Endoribonucleases