Nitric Oxide Regulates Protein Methylation during Stress Responses in Plants

5 years ago

Nitric Oxide Regulates Protein Methylation during Stress Responses in Plants

Methylation and nitric oxide (NO)-based S-nitrosylation are highly conserved protein posttranslational modifications that regulate diverse biological processes. In higher eukaryotes, PRMT5 catalyzes Arg symmetric dimethylation, including key components of the spliceosome. The Arabidopsis prmt5 mutant shows severe developmental defects and impaired stress responses. However, little is known about the mechanisms regulating the PRMT5 activity. Here, we report that NO positively regulates the PRMT5 activity through S-nitrosylation at Cys-125 during stress responses. In prmt5-1 plants, a PRMT5 ^C125S transgene, carrying a non-nitrosylatable mutation at Cys-125, fully rescues the developmental defects, but not the stress hypersensitive phenotype and the responsiveness to NO during stress responses. Moreover, the salt-induced Arg symmetric dimethylation is abolished in PRMT5 ^C125S/prmt5-1 plants, correlated to aberrant splicing of pre-mRNA derived from a stress-related gene. These findings define a mechanism by which plants transduce stress-triggered NO signal to protein methylation machinery through S-nitrosylation of PRMT5 in response to environmental alterations.

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Teaser

Hu et al. report that nitric oxide positively regulates the methyltransferase activity of Arabidopsis PRMT5 through S-nitrosylation at Cys-125 during stress responses. S-nitrosylation at Cys-125 enhances the level of Arg symmetric dimethylation, leading to proper splicing-specific pre-mRNA of stress-related genes and eventually boosting the tolerance to stresses.

Publisher URL: www.sciencedirect.com/science

DOI: S1097276517304653