Abstract

The majority of the secretory and transmembrane proteins are folded in the endoplasmic reticulum (ER). When unfolded proteins accumulate in the ER, a collective of signalling pathways, termed the unfolded protein response (UPR), are activated to restore the ER protein folding homeostasis. The most evolutionarily conserved branch of UPR is mediated by the kinase/endoribonuclease Ire1. Ire1 mediates a cytosolic non-conventional mRNA splicing reaction of HAC1 mRNA in yeast and XBP1 mRNA in mammalian cells. The spliced HAC1/XBP1 mRNA is translated and produces a functional transcription factor, which initiates a transcriptional response to restore the protein folding homeostasis. The HAC1/XBP1 mRNA splicing reaction is biochemically distinct from the ones that are catalyzed by the spliceosome. Here, we review recent studies that provide a mechanistic understanding of the non-conventional mRNA splicing reaction.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.