Phylogeny of the C3/C4/C5 complement-component gene family indicates that C5 diverged first.
نویسنده
چکیده
A phylogenetic analysis of DNA sequences from the C3/C4/C5 complement-component family of vertebrates supported the hypothesis that the C5 gene diverged first from the common ancestor of C3 and C4 and that C3 and C4 diverged later. The close relationship of C3 and C4 was further supported by the fact that a hagfish complement-component gene showed evidence of being more closely related to both C3 and C4 than to C5. This phylogeny is most consistent with the hypothesis that the alternative complement pathway was the first to evolve, followed by the terminal pathway and then by the classical pathway.
منابع مشابه
Genetics of human complement component C4 and evolution the central MHC.
The two classes of human complement component C4 proteins C4A and C4B manifest differential chemical reactivities and binding affinities towards target surfaces and complement receptor CR1. There are multiple, polymorphic allotypes of C4A and C4B proteins. A complex multiplication pattern of C4A and C4B genes with variations in gene size, gene dosage and flanking genes exists in the population....
متن کاملComplement biosynthesis by the human hepatoma-derived cell line HepG2.
The human hepatoma-derived cell line, HepG2, synthesized and secreted functional complement proteins C1r, C1s, C2, C3, C4, C5, factor B, C1 inhibitor, C3b inactivator, a small amount of C6, and trace amounts of C8; but failed to produce detectable C1q, C7, or C9. Immunochemically, C2, C3, C4, C5, and B were isolated from culture medium as proteins with molecular sizes and subunit structures ide...
متن کاملActive sites in complement components C5 and C3 identified by proximity to indels in the C3/4/5 protein family.
We recently suggested that sites of length polymorphisms in protein families (indels) might serve as useful guides for locating protein:protein interaction sites. This report describes additional site-specific mutagenesis and synthetic peptide inhibition studies aimed at testing this idea for the paralogous complement C3, C4, and C5 proteins. A series of C5 mutants was constructed by altering t...
متن کاملStructural Basis for the Function of Complement Component C4 within the Classical and Lectin Pathways of Complement.
Complement component C4 is a central protein in the classical and lectin pathways within the complement system. During activation of complement, its major fragment C4b becomes covalently attached to the surface of pathogens and altered self-tissue, where it acts as an opsonin marking the surface for removal. Moreover, C4b provides a platform for assembly of the proteolytically active convertase...
متن کاملPulmonary alveolar type II epithelial cells synthesize and secrete proteins of the classical and alternative complement pathways.
The serum complement system is a major mediator of inflammation reactions. Two of the complement proteins, the third (C3) and fifth (C5) components, are precursors of potent phlogistic molecules, C3a and C5a. C5a has potent chemotactic activity and plays an active role in pulmonary inflammation. We present evidence suggesting that several complement proteins, including C5, are synthesized local...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Molecular biology and evolution
دوره 11 3 شماره
صفحات -
تاریخ انتشار 1994