The transmembrane kinase Ire1p is a site-specific endonuclease that initiates mRNA splicing in the unfolded protein response
Article Abstract:
The endoplasmic reticulum (ER) communicates with the nucleus via the unfolded protein response (UPR). This senses unfolded protein accumulation in the ER lumen, resulting in increased transcription of genes encoding ER-resident chaperones. The mRNA encoding the UPR transcription factor Hac1p is spliced in a way that requires tRNA ligase, although not the spliceosome. Ire1p, a transmembrane kinase in the ER, is shown to be a bifunctional enzyme, being a site-specific endoribonuclease cleaving HAC1 mRNA.
Publication Name: Cell
Subject: Biological sciences
ISSN: 0092-8674
Year: 1997
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tRNA ligase is required for regulated mRNA splicing in the unfolded protein response
Article Abstract:
The unfolded protein response (UPR) induces the transcription of genes involved in protein folding in response to the accumulation of unfolded proteins in the endoplasmic reticulum. Genetic studies on yeast have shown that tRNA ligase is an important component that contributes to the regulation of UPR generation during transcriptional activation of the genes encoding the unfolded proteins. Transcription is regulated by transcription factor Hac1p by binding to the UPR element and other DNA targets.
Publication Name: Cell
Subject: Biological sciences
ISSN: 0092-8674
Year: 1996
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Transcriptional induction of genes encoding endoplasmic reticulum resident proteins requires a transmembrane protein kinase
Article Abstract:
IRE 1, a gene present in S. Cerevisiae, encodes a transmembrane serine or threonine kinase, and is responsible for the trasmission of the unfolded protein signal across the endoplasmic seticulum (ER) or the inner nuclear membrane. The gene is necessary for cell viability under stress conditions, and causes the accumulation of unfolded proteins in the ER. IRE 1 is responsible for inositol prototrophy and the induction of ER resident proteins.
Publication Name: Cell
Subject: Biological sciences
ISSN: 0092-8674
Year: 1993
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