Campus Units

Genetics, Development and Cell Biology, Genetics and Genomics, Plant Sciences Institute

Document Type

Article

Publication Version

Accepted Manuscript

Publication Date

8-17-2018

Journal or Book Title

Autophagy

Volume

14

Issue

9

First Page

1562

Last Page

1573

DOI

10.1080/15548627.2018.1462426

Abstract

Macroautophagy/autophagy is a conserved process in eukaryotes that contributes to cell survival in response to stress. Previously, we found that endoplasmic reticulum (ER) stress induces autophagy in plants via a pathway dependent upon AT5G24360/IRE1B (INOSITOL REQUIRING 1–1), an ER membrane-anchored factor involved in the splicing of AT1G42990/BZIP60 (basic leucine zipper protein 60) mRNA. IRE1B is a dual protein kinase and ribonuclease, and here we determined the involvement of the protein kinase catalytic domain, nucleotide binding and RNase domains of IRE1B in activating autophagy. We found that the nucleotide binding and RNase activity of IRE1B, but not its protein kinase activity or splicing target BZIP60, are required for ER stress-mediated autophagy. Upon ER stress, the RNase activity of IRE1B engages in regulated IRE1-dependent decay of messenger RNA (RIDD), in which mRNAs of secreted proteins are degraded by IRE1 upon ER stress. Twelve genes most highly targeted by RIDD were tested for their role in inhibiting ER stress-induced autophagy, and 3 of their encoded proteins, AT1G66270/BGLU21 (β-glucosidase 21), AT2G16005/ROSY1/ML (MD2-related lipid recognition protein) and AT5G01870/PR-14 (pathogenesis-related protein 14), were found to inhibit autophagy upon overexpression. From these findings, IRE1B is posited to be a ‘licensing factor’ linking ER stress to autophagy by degrading the RNA transcripts of factors that interfere with the induction of autophagy.

Comments

This is a manuscript of an article published as Bao, Yan, Yunting Pu, Xiang Yu, Brian D. Gregory, Renu Srivastava, Stephen H. Howell, and Diane C. Bassham. "IRE1B degrades RNAs encoding proteins that interfere with the induction of autophagy by ER stress in Arabidopsis thaliana." Autophagy 14, no. 9 (2018): 1562-1573. doi: 10.1080/15548627.2018.1462426. Posted with permission.

Copyright Owner

Informa UK Limited, trading as Taylor & Francis Group

Language

en

File Format

application/pdf

Published Version

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