Deiminated proteins in extracellular vesicles and plasma of nurse shark (Ginglymostoma cirratum) - Novel insights into shark immunity. Issue 92 (September 2019)

• Record Type: Journal Article
• Authors: Criscitiello, Michael F.; Kraev, Igor; Lange, Sigrun
• Is Part Of: Fish & shellfish immunology. Issue 92(2019)
• Page Start: 249
• Page End: 255
• Publication Date: 2019-09
• Subjects: Peptidylarginine deiminases (PADs) -- Protein deimination -- Shark (Ginglymostoma cirratum) -- Extracellular vesicles (EVs) -- Innate immunity -- Adaptive immunity -- Complement C3 -- Novel antigen receptor (NAGR) -- IgW -- Alpha 2-macroglobulin -- Hemopexin -- Haptoglobin; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2019.06.012
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Peptidylarginine deiminases (PADs) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, causing functional and structural changes in target proteins. Protein deimination causes generation of neo-epitopes, affects gene regulation and also allows for protein moonlighting. Extracellular vesicles are found in most body fluids and participate in cellular communication via transfer of cargo proteins and genetic material. In this study, post-translationally deiminated proteins and extracellular vesicles (EVs) are described for the first time in shark plasma. We report a poly-dispersed population of shark plasma EVs, positive for phylogenetically conserved EV-specific markers and characterised by TEM. In plasma, 6 deiminated proteins, including complement and immunoglobulin, were identified, whereof 3 proteins were found to be exported in plasma-derived EVs. A PAD homologue was identified in shark plasma by Western blotting and detected an expected 70 kDa size. Deiminated histone H3, a marker of neutrophil extracellular trap formation, was also detected in nurse shark plasma. This is the first report of deiminated proteins in plasma and EVs, highlighting a hitherto unrecognized post-translational modification in key immune proteins of innate and adaptive immunity in shark. Highlights: Deiminated proteins are identified for the first time in nurse shark. Key proteins of innate and adaptive immunity are deiminated in shark plasma. EVs are characterised in shark plasma for the first time. Deiminated EV protein cargo in plasma includes acute phase proteins.