Ire1

Function

Ire1 or serine/threonine protein kinase/endoribonuclease Ire1. It is important in altering gene expression as a response to endoplasmic reticulum-based stress signals^[1]. The endoribonuclase domain of Ire1 is a transcriptional activator which triggers growth arrest and apoptosis. The kinase domain of Ire1 is required for activation of the endoribonuclase domain. Ire1 senses unfolded proteins causing its auto-activation.

Structural highlights

Yeast Ire1 structure contains 3 phosphorylated residues: . Ire1 shows a different and for quercetin. Quercetin is a powerful activator of Ire1. ^[2].

3D structures of Ire1

2hz6, 6shc – hIre1 luminal domain 24-419 (mutant) – human
4z7g, 5hgi – hIre1 cytoplasmic domain 547-977
3p23, 4yzd - hIre1 cytoplasmic domain + ADP
4u6r, 4yz9, 4z7h, 6urc, 6hv0, 6hx1 – hIre1 cytoplasmic domain + inhibitor
4yzc – hIre1 cytoplasmic domain + satuorosporine
4pl3, 4pl4, 4pl5 – mIre1 cytoplasmic domain (mutant) + inhibitor – mouse
2rio, 3fbv, 3sdm – yIre1 cytoplasmic domain – yeast
3sdj - yIre1 cytoplasmic domain (mutant)
2bei – yIre1 lumenal domain + peptide
3lj0 - yIre1 cytoplasmic domain + quercetin + ADP
3lj1, 3lj2 - yIre1 cytoplasmic domain + inhibitor

References

1. ↑ Urano F, Bertolotti A, Ron D. IRE1 and efferent signaling from the endoplasmic reticulum. J Cell Sci. 2000 Nov;113 Pt 21:3697-702. PMID:11034898
2. ↑ Chen Y, Brandizzi F. IRE1: ER stress sensor and cell fate executor. Trends Cell Biol. 2013 Nov;23(11):547-55. doi: 10.1016/j.tcb.2013.06.005. Epub, 2013 Jul 21. PMID:23880584 doi:http://dx.doi.org/10.1016/j.tcb.2013.06.005