Proteomic Analyses of Plant Exosomes

Extracellular vesicles (EVs) have been identified as high potential vesicles for intercellular communication. Although their physiological roles have not been identified clearly, they are spherical, non‐organelle lipid membrane vesicles. Recent studies show that mammalian EVs contain RNA, proteins, and lipids implicated to be essential for their transfer [1] . EVs have three subgroups, which are apoptotic bodies, ectosomes, and exosomes. Exosome is the smallest EV with 50–100 nm diameter and their content is specific to the originated cell. Exosomes play the critical role in cell‐to‐cell communication and promote cellular activities such as stimulation of immune response, lysosome‐like activities or transfer of the antigens to other cells [2] . They have also a potential for biomarker design and cellular targeting based on their RNA and protein specification [3] . Plant cells are also demonstrated to produce exosomes with limited knowledge [4] . Given the available databases for animal exosomes, there is no database for plant exosomes up to date. We present our initial results for protein contents of plant exosomes to be used for the construction of such a database. In this study, Apium graveolens (Celery) exosomes were characterized by mass spectrometry‐based proteomic analysis. Following exosome isolation by using in‐house generated procedure from celery extract, proteins were precipitated with cold acetone. The peptide fractions obtained with filter‐aided sample preparation (FASP) analyzed with nanoLC‐captivespray‐qTOF‐MS/MS (Thermo Dionex RSLC3000 coupled with Bruker Compact). Data were submitted to MASCOT database against green plants to identify proteins. Support or Funding Information We would like to thank Prof. Dr. Fikrettin Şahin, Dr. P. Neslihan Taşlı, Kaan Kırbaş and members of YediPROT laboratory for their contribution to this project. This project was supported by Yeditepe University. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .