Systematic Identification and Analysis of Lysine Succinylation in Strawberry Stigmata

The
various post-translational modifications (PTMs) of plant proteins
have important regulatory roles in development. We therefore examined
various modified proteins from strawberry stigmata and found that
succinylation of lysine residues was the most abundant type of modification.
We then subjected proteins from strawberry stigmata to an efficient
enrichment method for succinylated peptides and identified 200 uniquely
succinylated lysines (Suks) in 116 proteins. A bioinformatics
analysis revealed that these proteins are involved in important biological
processes, including stress responses, vesicular transport, and energy
metabolism. Proteomics, combined with immunoprecipitation and immunoblotting,
revealed an obvious increase in succinylation of the assembly polypeptide
2 (AP2) and clathrin from 0.5 to 2 h after pollination, suggesting
that succinylation is involved in the recognition of pollen–stigma
signaling substances and vesicular transport. These results suggest
that AP2/clathrin-mediated vesicular transport processes are regulated
by lysine succinylation during pollen recognition.