Grape ASR-silencing sways nuclear proteome and histone marks

ABSTRACT: The biological roles of ASRs (Abscisic acid, Stress, Ripening proteins) involved in certain crucial switches of plant development (grain and pollen germination, senescence, fruit ripening), and responses to environmental cues (drought, salinity, cold, nutrient depletion, fungus infection, heavy metal toxicity) remain still elusive. The functional duality of ASRs, as chaperones for direct protection of biological macromolecules, and as transcriptional regulators of gene expression, needs in-depth understanding of the underlying mechanisms. To further elucidate the biological functions of ASRs a quantitative proteomic analysis (iTRAQ) was performed comparing the nuclear proteins of grapevine embryogenic 41B cells: wild-type (WT) and genetically modified VvMSA-RNAi cells, silenced for grape ASR. Among all identified proteins, thirty-one were differentially expressed in WT and VvMSA-silenced cells and may be classified into five functional groups: metabolism, stress responses, ribosome biogenesis, transcription and chromatin architecture/remodeling. The impact of VvMSA silencing was also confirmed at the level of the genes encoding the differentially expressed nuclear proteins, and the revealed most pronounced effects at protein level suggest a more direct correlation to the putative biological function. Remarkably, many of the thirty-one differentially expressed proteins are supposedly involved in epigenetic events. To further corroborate this hypothesis immunoblot assay of Multiscreen type was performed using twenty-one antibodies to different post-translational modifications (PTMs) of histones H3 and H4 in both cell types, WT and VvMSA-RNAi. The subsequent ImageQuant analysis revealed marked semi-quantitative differences in most PTMs of grape histones H3 and H4, with sharp increase of H3K27ac, H3K36me3, H4K5ac and H4K12ac, as well as a strong decrease of H3K27me3 in VvMSA-RNAi cells. These findings provide new insights on a plausible role of VvMSA as an ASR protein involved in epigenetic mechanisms

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Vitis Vinifera (grape)

SUBMITTER: Bernd Roschitzki  

LAB HEAD: Rossitza Atanassova

PROVIDER: PXD004988 | Pride | 2022-02-22

REPOSITORIES: Pride