Complement factor B/C2 in molluscs regulates agglutination and illuminates evolution of the Bf/C2 family

Complement factor B/C2 family (Bf/C2F) proteins are core complement system components in vertebrates that are absent in invertebrates and have been lost by numerous species, raising evolutionary questions. At least 3 duplication events have occurred from Cnidaria (ancestor) to mammals. Type II Bf/C2 genes appeared during separation of Proterostomia and Deuterostomes. The second event occurred during separation of vertebrates and invertebrates, yielding type II‐2 Bf/C2. The third event occurred when jawed and jawless fish were separated, eventually producing Bf and C2 genes. Herein, we report the second mollusc Sinonovacula constricta Bf/C2‐type gene (ScBf). ScBf is similar to Ruditapes decussatus Bf‐like because both lack the first complement control protein module at the N terminus present in mammalian Bf/C2 proteins. Uniquely, the Ser protease (SP) module at the C terminus of ScBf is ~50 aa longer than in other complement factor B/C2‐type (Bf/C2T) proteins, and is Glu‐rich. Bf/C2T proteins in molluscs lack the catalytic Ser in the SP module. Surprisingly, ScBf regulates rabbit erythrocyte agglutination, during which it is localized on the erythrocyte surface. Thus, ScBf may mediate the agglutination cascade and may be an upstream regulator of this process. Our findings provide new insight into the origin of the Bf/C2F.—Peng, M., Li, Z., Niu, D., Liu, X., Dong, Z., Li, J. Complement factor B/C2 in molluscs regulates agglutination and illuminates evolution of the Bf/C2 family. FASEB J. 33, 13323–13333 (2019). www.fasebj.org

[1]  Junping Gao,et al.  EGR2 phosphatase regulates OST1 kinase activity and freezing tolerance in Arabidopsis , 2018, The EMBO journal.

[2]  Jun Zheng,et al.  Deacetylation of serine hydroxymethyl-transferase 2 by SIRT3 promotes colorectal carcinogenesis , 2018, Nature Communications.

[3]  Jiale Li,et al.  Hemolytic reactions in the hemolymph of bivalve Sinonovacula constricta show complement‐like activity , 2018, Fish & shellfish immunology.

[4]  Jiale Li,et al.  Expression of a novel complement C3 gene in the razor clam Sinonovacula constricta and its role in innate immune response and hemolysis , 2017, Developmental and comparative immunology.

[5]  Jiale Li,et al.  Complement C3 gene: Expression characterization and innate immune response in razor clam Sinonovacula constricta. , 2016, Fish & shellfish immunology.

[6]  V. Frémeaux-Bacchi,et al.  Complement System Part I – Molecular Mechanisms of Activation and Regulation , 2015, Front. Immunol..

[7]  Reo Sekiguchi,et al.  Evolution of the complement system in protostomes revealed by de novo transcriptome analysis of six species of Arthropoda. , 2015, Developmental and comparative immunology.

[8]  Jiale Li,et al.  Identification and expression characterization of the myostatin (MSTN) gene and association analysis with growth traits in the razor clam Sinonovacula constricta. , 2015, Gene.

[9]  P. Heeger,et al.  Molecules Great and Small: The Complement System. , 2015, Clinical journal of the American Society of Nephrology : CJASN.

[10]  Zuoren Wang,et al.  The role of PPK26 in Drosophila larval mechanical nociception. , 2014, Cell reports.

[11]  A. Yee,et al.  von Willebrand Factor: Form for Function , 2013, Seminars in Thrombosis & Hemostasis.

[12]  Jiale Li,et al.  Molecular characterization and expression analysis of four cathepsin L genes in the razor clam, Sinonovacula constricta. , 2013, Fish & shellfish immunology.

[13]  Yaqing Chang,et al.  Gene cloning and function analysis of complement B factor-2 of Apostichopus japonicus. , 2012, Fish & shellfish immunology.

[14]  S. Kawabata,et al.  Proteolytic cascades and their involvement in invertebrate immunity. , 2010, Trends in biochemical sciences.

[15]  M. Nonaka,et al.  Multi-component complement system of Cnidaria: C3, Bf, and MASP genes expressed in the endodermal tissues of a sea anemone, Nematostella vectensis. , 2009, Immunobiology.

[16]  A. Figueras,et al.  Characterization of a C3 and a factor B-like in the carpet-shell clam, Ruditapes decussatus. , 2009, Fish & shellfish immunology.

[17]  T. Fujita,et al.  Factor C Acts as a Lipopolysaccharide-Responsive C3 Convertase in Horseshoe Crab Complement Activation12 , 2008, The Journal of Immunology.

[18]  Shicui Zhang,et al.  Molecular and immunochemical demonstration of a novel member of Bf/C2 homolog in amphioxus Branchiostoma belcheri: implications for involvement of hepatic cecum in acute phase response. , 2008, Fish & shellfish immunology.

[19]  P. Gros,et al.  Factor B structure provides insights into activation of the central protease of the complement system , 2007, Nature Structural &Molecular Biology.

[20]  M. Nonaka,et al.  Genomic view of the evolution of the complement system , 2006, Immunogenetics.

[21]  J. Lambris,et al.  Structural Biology of the Complement System , 2005 .

[22]  N. Satoh,et al.  Structure and the evolutionary implication of the triplicated complement factor B genes of a urochordate ascidian, Ciona intestinalis , 2005, Immunogenetics.

[23]  J. L. Ding,et al.  The ancient origin of the complement system , 2005, The EMBO journal.

[24]  M. Nonaka,et al.  Primitive complement system of invertebrates , 2004, Immunological reviews.

[25]  M. Flajnik,et al.  Molecular Cloning of C4 Gene and Identification of the Class III Complement Region in the Shark MHC 1 , 2003, The Journal of Immunology.

[26]  Junichi Takagi,et al.  Structures of the αL I Domain and Its Complex with ICAM-1 Reveal a Shape-Shifting Pathway for Integrin Regulation , 2003, Cell.

[27]  Junichi Takagi,et al.  Integrin activation and structural rearrangement , 2002, Immunological reviews.

[28]  J. Volanakis,et al.  Complement activation in factor D-deficient mice , 2001, Proceedings of the National Academy of Sciences of the United States of America.

[29]  M. Kirkitadze,et al.  Structure and flexibility of the multiple domain proteins that regulate complement activation , 2001, Immunological reviews.

[30]  Richard W. Farndale,et al.  Structural Basis of Collagen Recognition by Integrin α2β1 , 2000, Cell.

[31]  L. Smith,et al.  Coelomocytes express SpBf, a homologue of factor B, the second component in the sea urchin complement system. , 1998, Journal of immunology.

[32]  H. Colten,et al.  Abrogation of the alternative complement pathway by targeted deletion of murine factor B. , 1997, Proceedings of the National Academy of Sciences of the United States of America.

[33]  S. Narayana,et al.  Complement factor D, a novel serine protease , 1996, Protein science : a publication of the Protein Society.

[34]  M. Nonaka,et al.  Molecular cloning of a lamprey homologue of the mammalian MHC class III gene, complement factor B. , 1994, Journal of immunology.

[35]  J. Harper,et al.  Human complement proteins D, C2, and B. Active site mapping with peptide thioester substrates. , 1987, The Journal of biological chemistry.

[36]  J. Kearney,et al.  Probing functional sites on complement protein B with monoclonal antibodies. Evidence for C3b-binding sites on Ba. , 1987, Journal of immunology.

[37]  M. Pangburn,et al.  The C3 convertase of the alternative pathway of human complement. Enzymic properties of the bimolecular proteinase. , 1986, The Biochemical journal.

[38]  C. Smith,et al.  MHC Class III products: an electron microscopic study of the C3 convertases of human complement , 1984, The Journal of experimental medicine.

[39]  Peter A. Ward,et al.  The complement system , 2010, Cell and Tissue Research.

[40]  M. Nakao,et al.  The Evolution of Complement System Functions and Pathways in Vertebrates , 2016 .

[41]  M. Nonaka Evolution of the complement system. , 2014, Sub-cellular biochemistry.

[42]  Wen-chao Song,et al.  Complement and its role in innate and adaptive immune responses , 2010, Cell Research.

[43]  John D Lambris,et al.  Ancient origin of the complement system: emerging invertebrate models. , 2007, Advances in experimental medicine and biology.

[44]  M. Shimaoka,et al.  Conformational regulation of integrin structure and function. , 2002, Annual review of biophysics and biomolecular structure.

[45]  D. Fearon,et al.  Structure and function of the complement receptors, CR1 (CD35) and CR2 (CD21). , 1989, Advances in immunology.

[46]  D. Hourcade,et al.  The Regulators of Complement Activation (RCA) Gene Cluster , 1989 .