Nitroalkylated proteins in Arabidopsis thaliana development identified by LC-MS/MS

ABSTRACT: Nitro-fatty acids (NO2-FAs) act as potent electrophiles due to the presence of a nitro group attached to the double bond in their carbon chain. This chemical configuration enables them to react with nucleophilic residues in proteins, specifically cysteines, histidines and lysines, via a process known as nitroalkylation. This post-translational modification (PTM) is not only capable of altering the structure, transport and catalytic function of target proteins, but, due to its reversible nature, it establishes itself as a highly selective cellular signalling mechanism. In plant organisms, nitroalkylation of recombinant ascorbate peroxidase (APX) and in vivo catalase in Arabidopsis thaliana by nitro-linolenic acid (NO₂-Ln) has been characterised. In the present work, in vivo nitroalkylated proteins targets by nitro-oleic acid (NO2-OA), nitro-linoleic acid (NO2-LA) and NO2-Ln has been identified in different Arabidopsis development, including the seed, vegetative, generative and senescence stages. This study explores this phenomenon in greater depth by identifying the target proteins modified in vivo by nitro-oleic acid (NO2-OA), nitro-linoleic acid (NO2-LA) and nitro-linolenic acid (NO2-Ln). The results reveal that nitroalkylation is a persistent PTM throughout the entire life cycle of Arabidopsis, although it is markedly more prevalent during the vegetative and generative stages compared with the seed and senescence stages. This modification predominantly affects proteins involved in energy metabolism, redox coenzymes and stress responses. Although all three types of NO₂-FAs interact with the three amino acids mentioned, cysteine is identified as the primary target residue; however, the adduct formed with this amino acid is significantly more labile and sensitive to fluctuations in redox state than those formed with histidine or lysine. Taken together, this evidence positions nitroalkylation as a master regulatory mechanism that enables the reprogramming of the plant’s energy flow, dynamically adjusting it to the needs of its life cycle or to the demands of survival in adverse conditions.

INSTRUMENT(S):

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Leaf

SUBMITTER: Lorena Aranda Caño  

LAB HEAD: Juan Bautista

PROVIDER: PXD060471 | Pride | 2026-09-29

REPOSITORIES: Pride