Mutation of Arabidopsis SME1 and Sm core assembly improves oxidative stress resilience.

Patrick Willems, Valerie Van Ruyskensvelde, Takanori Maruta, Robin Pottie, Álvaro D Fernández-Fernández, Jarne Pauwels, Matthew A Hannah, Kris Gevaert, Frank Van Breusegem, Katrien Van der Kelen

Free radical biology & medicine 2023 May 01

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Alternative splicing is a key posttranscriptional gene regulatory process, acting in diverse adaptive and basal plant processes. Splicing of precursor-messenger RNA (pre-mRNA) is catalyzed by a dynamic ribonucleoprotein complex, designated the spliceosome. In a suppressor screen, we identified a nonsense mutation in the Smith (Sm) antigen protein SME1 to alleviate photorespiratory H2O2-dependent cell death in catalase deficient plants. Similar attenuation of cell death was observed upon chemical inhibition of the spliceosome, suggesting pre-mRNA splicing inhibition to be responsible for the observed cell death alleviation. Furthermore, the sme1-2 mutants showed increased tolerance to the reactive oxygen species inducing herbicide methyl viologen. Both an mRNA-seq and shotgun proteomic analysis in sme1-2 mutants displayed a constitutive molecular stress response, together with extensive alterations in pre-mRNA splicing of transcripts encoding metabolic enzymes and RNA binding proteins, even under unstressed conditions. Using SME1 as a bait to identify protein interactors, we provide experimental evidence for almost 50 homologs of the mammalian spliceosome-associated protein to reside in the Arabidopsis thaliana spliceosome complexes and propose roles in pre-mRNA splicing for four uncharacterized plant proteins. Furthermore, as for sme1-2, a mutant in the Sm core assembly protein ICLN resulted in a decreased sensitivity to methyl viologen. Taken together, these data show that both a perturbed Sm core composition and assembly results in the activation of a defense response and in enhanced resilience to oxidative stress. Copyright © 2023 Elsevier Inc. All rights reserved.

Citation

Patrick Willems, Valerie Van Ruyskensvelde, Takanori Maruta, Robin Pottie, Álvaro D Fernández-Fernández, Jarne Pauwels, Matthew A Hannah, Kris Gevaert, Frank Van Breusegem, Katrien Van der Kelen. Mutation of Arabidopsis SME1 and Sm core assembly improves oxidative stress resilience. Free radical biology & medicine. 2023 May 01;200:117-129