Engineering ER-stress dependent non-conventional mRNA splicing

Elife. 2018 Jul 9;7:e35388. doi: 10.7554/eLife.35388.

Abstract

The endoplasmic reticulum (ER) protein folding capacity is balanced with the protein folding burden to prevent accumulation of un- or misfolded proteins. The ER membrane-resident kinase/RNase Ire1 maintains ER protein homeostasis through two fundamentally distinct processes. First, Ire1 can initiate a transcriptional response through a non-conventional mRNA splicing reaction to increase the ER folding capacity. Second, Ire1 can decrease the ER folding burden through selective mRNA decay. In Saccharomyces cerevisiae and Schizosaccharomyces pombe, the two Ire1 functions have been evolutionarily separated. Here, we show that the respective Ire1 orthologs have become specialized for their functional outputs by divergence of their RNase specificities. In addition, RNA structural features separate the splicing substrates from the decay substrates. Using these insights, we engineered an S. pombe Ire1 cleavage substrate into a splicing substrate, which confers S. pombe with both Ire1 functional outputs.

Keywords: RNA processing; S. cerevisiae; S. pombe; biochemistry; cell biology; chemical biology; evolutionary biology; non-conventional mRNA splicing; unfolded protein response.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Endoplasmic Reticulum Stress / genetics*
  • Genetic Engineering*
  • Membrane Glycoproteins / chemistry
  • Membrane Glycoproteins / metabolism
  • Nucleic Acid Conformation
  • Protein Domains
  • Protein Multimerization
  • Protein Serine-Threonine Kinases / chemistry
  • Protein Serine-Threonine Kinases / metabolism
  • RNA Splicing / genetics*
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Ribonucleases / metabolism
  • Saccharomyces cerevisiae / genetics*
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism
  • Schizosaccharomyces / genetics*
  • Schizosaccharomyces pombe Proteins / chemistry
  • Schizosaccharomyces pombe Proteins / metabolism
  • Substrate Specificity

Substances

  • Membrane Glycoproteins
  • RNA, Messenger
  • Saccharomyces cerevisiae Proteins
  • Schizosaccharomyces pombe Proteins
  • IRE1 protein, S cerevisiae
  • Protein Serine-Threonine Kinases
  • Ribonucleases