Functional Diversification of ER Stress Responses in Arabidopsis. Issue 2 (February 2020)

• Record Type: Journal Article
• Authors: Pastor-Cantizano, Noelia; Ko, Dae Kwan; Angelos, Evan; Pu, Yunting; Brandizzi, Federica
• Is Part Of: Trends in biochemical sciences. Volume 45:Issue 2(2020)
• Page Start: 123
• Page End: 136
• Publication Date: 2020-02
• Subjects: ER stress -- unfolded protein response (UPR) -- Arabidopsis thaliana.; Biochemistry -- Periodicals; 572
• DOI: 10.1016/j.tibs.2019.10.008
• Languages: English
• ISSNs: 0968-0004

Abstract

Abstract : The endoplasmic reticulum (ER) is responsible for the synthesis of one-third of the cellular proteome and is constantly challenged by physiological and environmental situations that can perturb its homeostasis and lead to the accumulation of misfolded secretory proteins, a condition referred to as ER stress. In response, the ER evokes a set of intracellular signaling processes, collectively known as the unfolded protein response (UPR), which are designed to restore biosynthetic capacity of the ER. As single-cell organisms evolved into multicellular life, the UPR complexity has increased to suit their growth and development. In this review, we discuss recent advances in the understanding of the UPR, emphasizing conserved UPR elements between plants and metazoans and highlighting unique plant-specific features. Highlights: The UPR is an essential signaling pathway that, although fundamentally conserved among eukaryotes, has some unique features in plants. The plant ER stress sensors IRE1/bZIP60 and bZIP28/17 (homologs of IRE1α/XBP1, and ATF6α/β, respectively) activate conserved UPR pathways, but have diversified functions in response to stress stimuli. Plant UPR TFs coordinate with nuclear co-regulators of other signaling pathways to modulate ER stress outputs. Genes conserved between metazoans and plants, such as BI-1 and NADPH oxidases, have developed unique functions in ER stress responses in plants. The UPR contributes to plant cell processes at least through the upregulation of noncanonical UPR genes via bZIP28 and bZIP17 regulation.