0 avis
Identification and functional characterization of S-nitrosated proteins during salt stress in Klebsormidium nitens
Archive ouverte
Edité par CCSD -
National audience. Nitric oxide (NO) is a major ubiquitous component of cell signaling triggering part of its effets through protein S-nitrosation. This post-translational modification impacts protein activities, their subcellular localization and ability to form protein complexes. Therefore, the characterization of S-nitrosated proteins is of major interest in elucidating NO functions. Previously, we provided evidences that land plants lack NO Synthase (NOS), the main NO-synthesizing enzyme in metazoans (Jeandroz et al., 2016). In contrast, few algal species possess NOS isoforms, thus questioning their biochemistry and roles in these organisms. We focused on the identification of S-nitrosated proteins in Klebsormidium nitens, a freshwater algal species possessing two NOS isoforms and considered as a model to study plants adaptation to land (Chatelain et al., 2022). 43 candidate proteins with significantly higher levels of S-nitrosation under salt stress condition were identified. Orthology analysis was performed against Arabidopsis thaliana to determine the potential function of these proteins. Among them, we selected Inositol Polyphosphate Multikinase 2 (IPK2), which is potentially involved in cell signaling and stress response. KnIPK2 is able to phosphorylate as well as, more surprisingly, dephosphorylate certain inositol phosphates (InsP). Confirming our in silico predictions, in vitro S-nitrosation of KnIPK2 by exogenous NO inhibits its activity, suggesting the involvement of NO in the regulation of InsP metabolism. This modulation could play a role in cell signaling, as some InsP are major intracellular messengers interacting with calcium signaling. This project will provide a better understanding of NO functions in an algae possessing a NOS.
Consulter en ligne
Suggestions
Du même auteur
