Complement component C4-like protein in Atlantic cod (Gadus morhua L.) - Detection in ontogeny and identification of post-translational deimination in serum and extracellular vesicles. (December 2019)

• Record Type: Journal Article
• Authors: Lange, Sigrun; Kraev, Igor; Magnadóttir, Bergljót; Dodds, Alister W.
• Is Part Of: Developmental and comparative immunology. Volume 101(2019)
• Publication Date: 2019-12
• Subjects: Complement C4 -- Protein deimination -- Extracellular vesicles (EVs) -- Ontogeny -- Cod (Gadus morhua L.); Immunology -- Periodicals; Developmental immunology -- Periodicals; 616.079
• DOI: 10.1016/j.dci.2019.103437
• Languages: English
• ISSNs: 0145-305X

Abstract

Abstract: The complement system is a critical part of teleost immune defences, with complement component C4 forming part of the classical and lectin pathways. Cod C4-like protein was isolated from plasma, specific antibodies generated and C4-like protein was assessed in cod sera, mucus and in extracellular vesicles (EVs) from serum and mucus. Higher levels of C4-like protein were detected in serum- than mucus-derived EVs. Post-translational deimination, caused by conversion of arginine into citrulline, can affect protein structure and function. Here we detected deiminated forms of C4-like protein in cod serum and at lower levels in mucus. C4-like protein was also found in deiminated form at low levels in EVs from both serum and mucus. C4-like protein was assessed by immunohistochemistry in cod larvae and detected in a range of organs including in liver, kidney, gut, muscle, skin and mucus, as well as in neuronal tissues of the brain, spinal cord and eye. This abundance of C4-like protein during early development may indicate roles in tissue remodelling, in addition to immune defences. The presence of deiminated C4-like protein in serum and mucosa, as well as in EVs, may suggest C4 protein moonlighting via post-translational deimination. Highlights: Complement component C4-like protein is described for the first time in cod. C4-like protein is detected in serum, mucus, extracellular vesicles and a range of cod larval organs. Post-translational deimination of C4-like protein differs between serum and mucus. C4-like protein is exported in extracellular vesicles of serum and mucus at low levels. C4-like protein is exported in deiminated forms in EVs at low levels.