Journal Article

Protein and metabolite composition of Arabidopsis stress granules

Sokolowska, Ewelina M., Moreno, Juan C., Sofroni, Kostika, Schmidt, Stephan, Skirycz, Aleksandra, Luzarowski, Marcin, Schnittger, Arp, Kosmacz, Monika, Gorka, Michał, Leniak, Ewa, Szlachetko, Jagoda

2019

Overview

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. In this study, we addressed the existing gap. Importantly, we also provide evidence for metabolite sequestration within the SGs. To isolate SGs we used Arabidopsis seedlings expressing green fluorescent protein (GFP) fusion of the SGs marker protein, Rbp47b, and an experimental protocol combining differential centrifugation with affinity purification (AP). SGs isolates were analysed 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, nucleotides, amino acids and phospholipids also accumulated in SGs. Taken together, our results indicated the presence of a preexisting SG protein interaction network; an evolutionary conservation of the proteins involved in SG assembly and dynamics; an important role for SGs in moderation of stress responses by selective storage of proteins and metabolites.

• Publisher: Wiley,Wiley Subscription Services, Inc
• Subject: Adaptation / affinity purification / Amino Acid Sequence / Amino acids / Arabidopsis / Arabidopsis - genetics / Arabidopsis - metabolism / Arabidopsis Proteins - chemistry / Arabidopsis Proteins - isolation & purification / Arabidopsis Proteins - metabolism / Arabidopsis thaliana / CDKA1 / Centrifugation / Centrifuging / Composition / cyclin-dependent kinase / cytoplasmic granules / Cytoplasmic Granules - metabolism / Dynamics / Evolutionary conservation / Fluorescence / Fusion protein / Granular materials / Green fluorescent protein / Kinases / Mass spectrometry / Mass spectroscopy / messenger RNA / Metabolites / Metabolome / Metabolomics / Nucleotides / Phospholipids / Plant Leaves - metabolism / plant response / Plant Roots - metabolism / Plants, Genetically Modified / Protein Binding / Protein composition / Protein purification / Proteins / proteome / Proteome - metabolism / Proteomics / Regulators / Seedlings / Seedlings - metabolism / Storage / stress granule extraction / stress granule metabolome / stress granule proteome / stress response / Stress, Physiological / Water purification