C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions
Complement C1 is the defining component of the classical pathway. Within the C1qC1r2C1s2 complex, C1q functions as a molecular scaffold for C1r2C1s2 and C1q binding to its ligands activates these two serine proteases. The classic C1q ligands are antigen-bound antibodies and activated C1s cleaves C4...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2017-05-01
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| Series: | Frontiers in Immunology |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/article/10.3389/fimmu.2017.00592/full |
| _version_ | 1819294967695147008 |
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| author | Jinhua Lu Uday Kishore |
| author_facet | Jinhua Lu Uday Kishore |
| author_sort | Jinhua Lu |
| collection | DOAJ |
| description | Complement C1 is the defining component of the classical pathway. Within the C1qC1r2C1s2 complex, C1q functions as a molecular scaffold for C1r2C1s2 and C1q binding to its ligands activates these two serine proteases. The classic C1q ligands are antigen-bound antibodies and activated C1s cleaves C4 and C2 to initiate the complement cascade. Recent studies suggest broad C1 functions beyond the complement system. C1q binds to the Frizzled receptors to activate C1s, which cleaves lipoprotein receptor-related protein 6 to trigger aging-associated Wnt receptor signaling. C1q binds to apoptotic cells and the activated C1 proteases cleave nuclear antigens. C1s also cleaves MHC class I molecule and potentially numerous other proteins. The diversity of C1q ligands and C1 protease substrates renders C1 complex versatile and modular so that it can adapt to multiple molecular and cellular processes besides the complement system. |
| first_indexed | 2024-12-24T04:34:44Z |
| format | Article |
| id | doaj.art-fa9cadb503d34744b87fd5daef32686a |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-12-24T04:34:44Z |
| publishDate | 2017-05-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Immunology |
| spelling | doaj.art-fa9cadb503d34744b87fd5daef32686a2022-12-21T17:15:15ZengFrontiers Media S.A.Frontiers in Immunology1664-32242017-05-01810.3389/fimmu.2017.00592259880C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement FunctionsJinhua Lu0Uday Kishore1Department of Microbiology and Immunology, Yong Loo Lin School of Medicine and Immunology Programme, National University of Singapore, SingaporeDepartment of Life Sciences, College of Health and Life Sciences, Brunel University London, Uxbridge, UKComplement C1 is the defining component of the classical pathway. Within the C1qC1r2C1s2 complex, C1q functions as a molecular scaffold for C1r2C1s2 and C1q binding to its ligands activates these two serine proteases. The classic C1q ligands are antigen-bound antibodies and activated C1s cleaves C4 and C2 to initiate the complement cascade. Recent studies suggest broad C1 functions beyond the complement system. C1q binds to the Frizzled receptors to activate C1s, which cleaves lipoprotein receptor-related protein 6 to trigger aging-associated Wnt receptor signaling. C1q binds to apoptotic cells and the activated C1 proteases cleave nuclear antigens. C1s also cleaves MHC class I molecule and potentially numerous other proteins. The diversity of C1q ligands and C1 protease substrates renders C1 complex versatile and modular so that it can adapt to multiple molecular and cellular processes besides the complement system.http://journal.frontiersin.org/article/10.3389/fimmu.2017.00592/fullcomplement C1autoimmunityaginginfectioninflammationC1q |
| spellingShingle | Jinhua Lu Uday Kishore C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions Frontiers in Immunology complement C1 autoimmunity aging infection inflammation C1q |
| title | C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions |
| title_full | C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions |
| title_fullStr | C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions |
| title_full_unstemmed | C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions |
| title_short | C1 Complex: An Adaptable Proteolytic Module for Complement and Non-Complement Functions |
| title_sort | c1 complex an adaptable proteolytic module for complement and non complement functions |
| topic | complement C1 autoimmunity aging infection inflammation C1q |
| url | http://journal.frontiersin.org/article/10.3389/fimmu.2017.00592/full |
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