Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein
Complement component C1q plays an important recognition role in adaptive, and innate, immunity through its ability to interact, via its six globular head regions, with both immunoglobulin and non-immunoglobulin activators of the complement system, and also in the clearance of cell debris, and by pla...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2018-04-01
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| Series: | Frontiers in Immunology |
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| Online Access: | http://journal.frontiersin.org/article/10.3389/fimmu.2018.00764/full |
| _version_ | 1818908751298560000 |
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| author | Kenneth B. M. Reid |
| author_facet | Kenneth B. M. Reid |
| author_sort | Kenneth B. M. Reid |
| collection | DOAJ |
| description | Complement component C1q plays an important recognition role in adaptive, and innate, immunity through its ability to interact, via its six globular head regions, with both immunoglobulin and non-immunoglobulin activators of the complement system, and also in the clearance of cell debris, and by playing a role in regulation of cellular events by interacting with a wide range of cell surface molecules. The presence of collagen-like triple-helical structures within C1q appears crucial to the presentation, and multivalent binding, of the globular heads of C1q to targets, and also to its association with the proenzyme complex of C1r2–C1s2, to yield the C1 complex. The possible role that movement of these collagen-like structures may play in the activation of the C1 complex is a controversial area, with there still being no definitive answer as to how the first C1r proenzyme molecule becomes activated within the C1 complex, thus allowing it to activate proenzyme C1s, and initiate and the consequent cascade of events in the activation of the classical pathway of complement. The globular heads of C1q are similar to domains found within the tumor necrosis factor (TNF) superfamily of proteins, and have been shown to bind to a very wide range of ligands. In addition to its well-defined roles in infection and immunity, a variety of other functions associated with C1q include possible roles, in the development of problems in the central nervous system, which occur with aging, and perhaps in the regulation of tumor growth. |
| first_indexed | 2024-12-19T22:15:59Z |
| format | Article |
| id | doaj.art-82cf6ff1e73d4479b0dea445410ba5b7 |
| institution | Directory Open Access Journal |
| issn | 1664-3224 |
| language | English |
| last_indexed | 2024-12-19T22:15:59Z |
| publishDate | 2018-04-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Immunology |
| spelling | doaj.art-82cf6ff1e73d4479b0dea445410ba5b72022-12-21T20:03:46ZengFrontiers Media S.A.Frontiers in Immunology1664-32242018-04-01910.3389/fimmu.2018.00764355171Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum ProteinKenneth B. M. ReidComplement component C1q plays an important recognition role in adaptive, and innate, immunity through its ability to interact, via its six globular head regions, with both immunoglobulin and non-immunoglobulin activators of the complement system, and also in the clearance of cell debris, and by playing a role in regulation of cellular events by interacting with a wide range of cell surface molecules. The presence of collagen-like triple-helical structures within C1q appears crucial to the presentation, and multivalent binding, of the globular heads of C1q to targets, and also to its association with the proenzyme complex of C1r2–C1s2, to yield the C1 complex. The possible role that movement of these collagen-like structures may play in the activation of the C1 complex is a controversial area, with there still being no definitive answer as to how the first C1r proenzyme molecule becomes activated within the C1 complex, thus allowing it to activate proenzyme C1s, and initiate and the consequent cascade of events in the activation of the classical pathway of complement. The globular heads of C1q are similar to domains found within the tumor necrosis factor (TNF) superfamily of proteins, and have been shown to bind to a very wide range of ligands. In addition to its well-defined roles in infection and immunity, a variety of other functions associated with C1q include possible roles, in the development of problems in the central nervous system, which occur with aging, and perhaps in the regulation of tumor growth.http://journal.frontiersin.org/article/10.3389/fimmu.2018.00764/fullC1 activationC1qcollagen-like structureglobular headstumoraging |
| spellingShingle | Kenneth B. M. Reid Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein Frontiers in Immunology C1 activation C1q collagen-like structure globular heads tumor aging |
| title | Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein |
| title_full | Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein |
| title_fullStr | Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein |
| title_full_unstemmed | Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein |
| title_short | Complement Component C1q: Historical Perspective of a Functionally Versatile, and Structurally Unusual, Serum Protein |
| title_sort | complement component c1q historical perspective of a functionally versatile and structurally unusual serum protein |
| topic | C1 activation C1q collagen-like structure globular heads tumor aging |
| url | http://journal.frontiersin.org/article/10.3389/fimmu.2018.00764/full |
| work_keys_str_mv | AT kennethbmreid complementcomponentc1qhistoricalperspectiveofafunctionallyversatileandstructurallyunusualserumprotein |