Protein and metabolite composition of Arabidopsis stress granules

ABSTRACT: • Stress granules (SGs) are evolutionary conserved aggregates of proteins and untranslated mRNAs formed in response to stress. Despite their importance for stress adaptation, no complete proteome composition has been reported for plant SGs. Herein, we addressed the existing gap. Importantly, we also provide evidence for metabolite sequestration within the SGs. • To isolate SGs we used Arabidopsis seedlings expressing GFP fusion of the SGs marker protein, Rbp47b, and an experimental protocol combining differential centrifugation with affinity purification. SGs isolates were analyzed using mass spectrometry-based proteomics and metabolomics. • A quarter of the identified proteins constituted known or predicted SG components. Intriguingly, the remaining proteins were enriched in key enzymes and regulators, such as cyclin dependent kinase A (CDKA), that mediate plant responses to stress. In addition to proteins, also nucleotides, amino acids and phospholipids accumulated in SGs. • Taken together, our results indicate (i) the presence of a pre-existing SG protein interaction network, (ii) an evolutionary conservation of the proteins involved in SG assembly and dynamics, (iii) an important role for SGs in moderation of stress responses by selective storage of proteins and metabolites.

INSTRUMENT(S): Q Exactive

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

SUBMITTER: Michal Gorka  

LAB HEAD: Aleksandra Skirycz

PROVIDER: PXD011716 | Pride | 2019-01-07

REPOSITORIES: Pride