Shotgun proteomics of coelomic fluid from the purple sea urchin, Strongylocentrotus purpuratus

• Published in: Developmental and comparative immunology 2013-05, Vol.40 (1), p.35-50
• Main Authors: Dheilly, Nolwenn M., Raftos, David A., Haynes, Paul A., Smith, L. Courtney, Nair, Sham V.
• Format: Article
• Language: English
• Subjects: Animals; antigen-antibody complex; Biodiversity and Ecology; blood cells; Blood Cells - metabolism; Blood Coagulation; blood coagulation factors; cadherins; calcium; Calcium - metabolism; Ceruloplasmin - metabolism; Coelomic fluid; complement; Complement System Proteins - metabolism; data collection; dissociation; Echinoderm; Echinoidea; Environmental Sciences; ferritin; Ferritins - metabolism; ferroxidase; fibrinogen; gene expression; genes; GTP-Binding Proteins - metabolism; guanine nucleotides; immune response; immune system; immunologic receptors; Innate immunity; iron; Iron - metabolism; lipoproteins; Marine; Mass Spectrometry; NAD(P)H oxidase (H2O2-forming); NADPH Oxidases - metabolism; proteomics; Proteomics - methods; reactive oxygen species; Receptors, Scavenger - metabolism; Shotgun proteomics; Signal Transduction; SRCR; Strongylocentrotus; Strongylocentrotus purpuratus; Strongylocentrotus purpuratus - metabolism; talin; transferrin; Transferrin - metabolism
• ISSN: 0145-305X; 1879-0089
• DOI: 10.1016/j.dci.2013.01.007

► A total of 307 proteins were identified with high confidence. ► A complex set of complement components are expressed in the coelomic fluid. ► Coelomocytes express different Scavenger Receptor Cysteine-rich proteins. ► The production of ROS and iron sequestration is consistent with an antimicrobial response. ► Numerous proteins may function in clotting reactions at wound sites. The purple sea urchin has a complex immune system that is likely mediated by gene expression in coelomocytes (blood cells). A broad array of potential immune receptors and immune response proteins has been deduced from their gene models. Here we use shotgun mass spectrometry to describe 307 proteins with possible immune function in sea urchins including proteins involved in the complement pathway and numerous SRCRs. The relative abundance of dual oxidase 1, ceruloplasmin, ferritin and transferrin suggests the production of reactive oxygen species in coelomocytes and the sequestration of iron. Proteins such as selectin, cadherin, talin, galectin, amassin and the Von Willebrand factor may be involved in generating a strong clotting reaction. Cell signaling proteins include a guanine nucleotide binding protein, the Rho GDP dissociation factor, calcium storage molecules and a variety of lipoproteins. However, based on this dataset, the expression of TLRs, NLRs and fibrinogen domain containing proteins in coelomic fluid and coelomocytes could not be verified.