The Proteome and Citrullinome of Hippoglossus hippoglossus Extracellular Vesicles—Novel Insights into Roles of the Serum Secretome in Immune, Gene Regulatory and Metabolic Pathways

Extracellular vesicles (EVs) are lipid bilayer which released from cells and play multifaceted roles in cellular communication health disease. EVs can be isolated various body fluids, including serum plasma, usable biomarkers as they inform status. Studies on an emerging research field teleost fish, with accumulating evidence for important functions immunity homeostasis, but remain to characterised most fish species, halibut. Protein deimination is a post-translational modification caused by conserved family of enzymes, named peptidylarginine deiminases (PADs), results changes protein folding function via conversion arginine citrulline target proteins. has been recently described halibut ontogeny serum. Neither EV profiles, nor total or deiminated cargos have yet assessed reported the current study. Halibut showed poly-dispersed population size range 50–600 nm, modal falling at 138 morphology was further confirmed transmission electron microscopy. The assessment cargo revealed 124 hits 37 hits, whereof 15 were particularly identified form only. interaction network analysis that involved gene regulatory, immune, metabolic developmental processes. same found cargo, although far wider pathways than expression complement component C3 C4, well pentraxin-like protein, proteomic analysis, verified western blotting. This exported higher levels C4 furthermore high deimination-enriched fractions, while, comparison, very low detection fractions. Pentraxin EVs, not detected Our findings provide novel insights into EV-mediated serum, transport post-translationally