Dataset Information

Surveying the chloroplast protein kinase preferences for cation cofactors in Arabidopsis thaliana

ABSTRACT: Survival of plants depends on their ability to adapt to ever-changing environmental conditions. Chloroplasts sense different stimuli and respond to ion fluxes in the cytosol triggering systemic responses under stress conditions. Indeed, changes in calcium and magnesium ion concentration in the chloroplast stroma impact the immune response against pathogens and adapt the photosynthetic machinery under fluctuating light conditions. Here we investigated the link between di-valent cations, calcium, magnesium and manganese and the protein kinase activity in Arabidopsis chloroplasts. Our results show that overall, manganese ions are the strongest activator of kinase activity in chloroplasts followed by magnesium ions, whereas calcium ions have seemingly no effect. Additionally, when comparing the phosphorylation pattern from Arabidopsis wild type and a cmt1 mutant, which is defective in manganese import into chloroplasts, the phosphorylation of specific protein bands is strongly reduced in the mutant chloroplasts supporting the notion that chloroplasts contain manganese-dependent protein kinases. These findings provide insights for the future characterization of chloroplast protein kinases activity regarding in-vitro assays and potential target proteins.

INSTRUMENT(S): impact II

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

TISSUE(S): Photosynthetic Cell, Leaf

SUBMITTER: Serena Schwenkert

LAB HEAD: Serena Schwenkert

PROVIDER: PXD037286 | Pride | 2023-03-11

REPOSITORIES: Pride

ACCESS DATA

Publications

Characterization of the preferred cation cofactors of chloroplast protein kinases in Arabidopsis thaliana.

Espinoza-Corral Roberto R Schwenkert Serena S Schneider Anja A

FEBS open bio 20230131 3

Chloroplasts sense a variety of stimuli triggering several acclimation responses. One prominent response is the mechanism of state transitions, which enables rapid adaption to changes in illumination. Here, we investigated the link between divalent cations (calcium, magnesium, and manganese) and protein kinase activity in Arabidopsis chloroplasts. Our results show that manganese ions are the strongest activator of kinase activity in chloroplasts followed by magnesium ions, whereas calcium ions a ...[more]

PMID: 36683405

Similar Datasets

Project description:In chloroplasts, homeostasis of the proteome maintained by protein synthesis, importation, and degradation is critical to the development of chloroplasts. The caseinolytic protease complex component CLPC1, a member of the HSP100 family of chaperones, not only facilitates the translocation of pre-proteins into chloroplasts, but also mediates protein degradation via its associated caseinolytic protease complex (CLPPs). Although CLPC1 has been shown to affect the abundance of some chloroplast proteins, its overall functions and coordination with other protease systems in maintaining proteome homeostasis have not been fully elucidated. Its possible roles in gene expression are also unclear. Here we used the iTRAQ technique to profile the chloroplast proteomes of the clpc1 mutant and its various complementation lines. Whereas proteins involved in photosynthesis were found to be dramatically decreased in the clcp1 mutant, many involved in chloroplast transcription and translation were increased. Expression of the full-length CLPC1 protein, but not of the N-terminal truncated form (ΔN), in clpc1 restored the level of most of these proteins to that of the wild type. Interestingly, the ΔN complementation line could also restore certain proteins to the wild type level. We found that nearly half of previously suggested candidate substrates of the CLPS1, another CLPP component, were mis-regulated in clpc1, indicating that CLPC1 greatly affects CLPS1 targets. We provide the first experimental evidence to show that CLPC1 profoundly affects gene transcription in chloroplasts. Sense transcripts of many chloroplast genes are up-regulated whereas antisense transcripts down-regulated in the clpc1 mutant. We propose that this altered transcript landscape is a result of the transcription and degradation dynamics conditioned by the changed proteomic profile in the mutant. Our study reveals that CLPC1 and likely the CLPP proteasome complex have a greater than previously recognized role in coordinating and maintaining the proteome and transcriptome homeostasis in chloroplasts.

Dataset Information

Surveying the chloroplast protein kinase preferences for cation cofactors in Arabidopsis thaliana

Publications

Characterization of the preferred cation cofactors of chloroplast protein kinases in Arabidopsis thaliana.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure