Phosphoregulation of Ire1 RNase splicing activity

Abstract

Ire1 is activated in response to accumulation of misfolded proteins within the endoplasmic reticulum as part of the unfolded protein response (UPR). It is a unique enzyme, possessing both kinase and RNase activity that is required for specific splicing of Xbp1 mRNA leading to UPR activation. How phosphorylation impacts on the Ire1 splicing activity is unclear. In this study, we isolate distinct phosphorylated species of Ire1 and assess their effects on RNase splicing both in vitro and in vivo . We find that phosphorylation within the kinase activation loop significantly increases RNase splicing in vitro. Correspondingly, mutants of Ire1 that cannot be phosphorylated on the activation loop show decreased specific Xbp1 and promiscuous RNase splicing activity relative to wild-type Ire1 in cells. These data couple the kinase phosphorylation reaction to the activation state of the RNase, suggesting that phosphorylation of the activation loop is an important step in Ire1-mediated UPR activation.

References 25

1. 1.

   Walter P. & Ron D. The unfolded protein response: from stress pathway to homeostatic regulation. Science 334, 1081–1086 (2011 ).

   Not in our library10.1126/science.1209038

2. 2.

   Zhang K. & Kaufman R. J. From endoplasmic-reticulum stress to the inflammatory response. Nature 454, 455–462 (2008 ).

   Not in our library10.1038/nature07203

3. 3.

   Ali M. M.. Structure of the Ire1 autophosphorylation complex and implications for the unfolded protein response. EMBO J. 30, 894–905 (2011 ).

   Not in our library10.1038/emboj.2011.18

4. 4.

   Korennykh A. V.. The unfolded protein response signals through high-order assembly of Ire1. Nature 457, 687–693 (2008 ).

   Not in our library10.1038/nature07661

5. 5.

   Lee K. P. K.. Structure of the dual enzyme Ire1 reveals the basis for catalysis and regulation in nonconventional rna splicing. Cell 132, 89–100 (2008 ).

   Not in our library10.1016/j.cell.2007.10.057

6. 6.

   Yanagitani K., Kimata Y., Kadokura H. & Kohno K. Translational pausing ensures membrane targeting and cytoplasmic splicing of XBP1u mRNA. Science 331, 586–589 (2011 ).

   Not in our library10.1126/science.1197142

7. 7.

   Ron D. & Walter P. Signal integration in the endoplasmic reticulum unfolded protein response. Nat. Rev. Mol. Cell. Biol. 8, 519–529 (2007 ).

   Not in our library10.1038/nrm2199

8. 8.

   Hetz C., Martinon F., Rodriguez D. & Glimcher L. H. The unfolded protein response: integrating stress singnals through the stress sensor Ire1α. Physiol. Rev. 91, 1219–1243 (2011 ).

   Not in our library10.1152/physrev.00001.2011

9. 9.

   Davies F. E. Insights into the multistep transformation of MGUS to myeloma using microarray expression analysis. Blood 102, 4504–4511 (2003 ).

   Not in our library10.1182/blood-2003-01-0016

10. 10.
    The Differentiation and Stress Response Factor XBP-1 Drives Multiple Myeloma Pathogenesis · 2007

    No notice
11. 11.

    Todd D. J., Lee A.-H. & Glimcher L. H. The endoplasmic reticulum stress response in immunity and autoimmunity. Nat. Rev. Immunol. 8, 663–674 (2008 ).

    Not in our library10.1038/nri2359

12. 12.

    Chawla A., Chakrabarti S., Ghosh G. & Niwa M. Attenuation of yeast UPR is essential for survival and is mediated by IRE1 kinase. J. Cell Biol. 193, 41–50 (2011 ).

    Not in our library10.1083/jcb.201008071

13. 13.

    Rubio C.. Homeostatic adaptation to endoplasmic reticulum stress depends on Ire1 kinase activity. J. Cell Biol. 193, 171–184 (2011 ).

    Not in our library10.1083/jcb.201007077

14. 14.

    Papa F. R., Zhang C., Shokat K. & Walter P. Bypassing a kinase activity with an ATP-competitive drug. Science 302, 1533–1537 (2003 ).

    Not in our library10.1126/science.1090031

15. 15.

    Shamu C. & Walter P. Oligomerization and phosphorylation of Ire1p kinase during intracelluar signalling from the endoplasmic reticulum to the nucleus. EMBO J. 15, 3028–3039 (1996 ).

    Not in our library

16. 16.

    Tirasophon W., Welihinda A. A. & Kaufman R. J. A stress response pathway from the endoplasmic reticulum to the nucleus requires a novel bifunctional protein kinase/endoribonuclease (Ire1p) in mammalian cells. Genes Dev. 12, 1812–1824 (1998 ).

    Not in our library10.1101/gad.12.12.1812

17. 17.

    Jha B. K.. Inhibition of RNase L and RNA-dependent protein kinase (PKR) by sunitinib impairs antiviral innate immunity. J. Biol. Chem. 286, 26319–26326 (2011 ).

    Not in our library10.1074/jbc.m111.253443

18. 18.

    Keshwani M. M., Ross D. B., Ragan T. J. & Harris T. K. Baculovirus-mediated expression, purification, and characterization of a fully activated catalytic kinase domain construct of the 70 kDa 40S ribosomal protein S6 kinase-1 alphaII isoform (S6K1alphaII). Protein Expr. Purif. 58, 32–41 (2008 ).

    Not in our library10.1016/j.pep.2007.11.003

19. 19.

    Klein S.. Expression and purification of active PKB kinase from Escherichia coli. Protein Expr. Purif. 41, 162–169 (2005 ).

    Not in our library10.1016/j.pep.2005.01.003

20. 20.

    Wiseman R. L.. Flavonol activation defines an unanticipated ligand-binding site in the kinase-RNase domain of IRE1. Mol. Cell. 38, 291–304 (2010 ).

    Not in our library10.1016/j.molcel.2010.04.001

21. 21.

    Cross B. C. S.. The molecular basis for selective inhibition of unconventional mRNA splicing by an IRE1-binding small molecule. Proc. Natl Acad. Sci. 109, E869–E878 (2012 ).

    Not in our library10.1073/pnas.1115623109

22. 22.

    Huse M. & Kuriyan J. The conformational plasticity of protein kinases. Cell 109, 275–282 (2002 ).

    Not in our library10.1016/s0092-8674(02)00741-9

23. 23.

    Shrestha A., Hamilton G., O’Neill E., Knapp S. & Elkins J. M. Analysis of conditions affecting auto-phosphorylation of human kinases during expression in bacteria. Protein Expr. Purif. 81, 136–143 (2012 ).

    Not in our library10.1016/j.pep.2011.09.012

24. 24.

    Hetz C. The unfolded protein response: controlling cell fate decisions under ER stress and beyond. Nat. Rev. Mol. Cell. Biol. 13, 89–102 (2012 ).

    Not in our library10.1038/nrm3270

25. 25.

    Woehlbier U. & Hetz C. Modulating stress responses by the UPRosome: a matter of life and death. Trends. Biochem. Sci. 36, 329–337 (2011 ).

    Not in our library10.1016/j.tibs.2011.03.001

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