Abstract
The human C3b/C4b receptor (CR1) is a Mr approximately equal to 200,000 single-chain integral membrane glycoprotein of human erythrocytes and leukocytes. It functions both as a receptor for C3b- and C4b-coated ligands and as a regulator of complement activation. Prior structural studies have defined an unusual molecular weight allelic polymorphism in which the allelic products differ in molecular weight by as much as 90,000. On peripheral blood cells there is codominant expression of CR1 gene products of Mr 190,000 (A), 220,000 (B), 160,000 (C), and 250,000 (D). Results of prior biosynthetic and tryptic peptide mapping experiments have suggested that the most likely basis for the allelic molecular weight differences is at the polypeptide level. In order to define further the molecular basis for these molecular weight differences, human CR1 was purified to homogeneity, tryptic peptide fragments were isolated by HPLC and sequenced, oligonucleotide probes were prepared, and a CR1 cDNA was identified. A subclone of this CR1 cDNA was used as a probe of RNA blots of Epstein-Barr virus-transformed cell lines expressing the allelic variants. Each allelic variant encodes two distinct transcripts. A mRNA size polymorphism was identified that correlated with the gene product molecular weight polymorphism. This finding, in addition to a prior report of several homologous repeats in CR1, is consistent with the hypothesis that the molecular weight polymorphism is determined at the genomic level and may have been generated by unequal crossing-over.
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Selected References
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- Atkinson J. P., Jones E. A. Biosynthesis of the human C3b/C4b receptor during differentiation of the HL-60 cell line. Identification and characterization of a precursor molecule. J Clin Invest. 1984 Nov;74(5):1649–1657. doi: 10.1172/JCI111581. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Blomberg B., Traunecker A., Eisen H., Tonegawa S. Organization of four mouse lambda light chain immunoglobulin genes. Proc Natl Acad Sci U S A. 1981 Jun;78(6):3765–3769. doi: 10.1073/pnas.78.6.3765. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chirgwin J. M., Przybyla A. E., MacDonald R. J., Rutter W. J. Isolation of biologically active ribonucleic acid from sources enriched in ribonuclease. Biochemistry. 1979 Nov 27;18(24):5294–5299. doi: 10.1021/bi00591a005. [DOI] [PubMed] [Google Scholar]
- Chung L. P., Bentley D. R., Reid K. B. Molecular cloning and characterization of the cDNA coding for C4b-binding protein, a regulatory protein of the classical pathway of the human complement system. Biochem J. 1985 Aug 15;230(1):133–141. doi: 10.1042/bj2300133. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dykman T. R., Cole J. L., Iida K., Atkinson J. P. Polymorphism of human erythrocyte C3b/C4b receptor. Proc Natl Acad Sci U S A. 1983 Mar;80(6):1698–1702. doi: 10.1073/pnas.80.6.1698. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dykman T. R., Hatch J. A., Aqua M. S., Atkinson J. P. Polymorphism of the C3b/C4b receptor (CR1): characterization of a fourth allele. J Immunol. 1985 Mar;134(3):1787–1789. [PubMed] [Google Scholar]
- Dykman T. R., Hatch J. A., Atkinson J. P. Polymorphism of the human C3b/C4b receptor. Identification of a third allele and analysis of receptor phenotypes in families and patients with systemic lupus erythematosus. J Exp Med. 1984 Mar 1;159(3):691–703. doi: 10.1084/jem.159.3.691. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fearon D. T. The human C3b receptor. Springer Semin Immunopathol. 1983;6(2-3):159–172. doi: 10.1007/BF00205871. [DOI] [PubMed] [Google Scholar]
- Feinberg A. P., Vogelstein B. A technique for radiolabeling DNA restriction endonuclease fragments to high specific activity. Anal Biochem. 1983 Jul 1;132(1):6–13. doi: 10.1016/0003-2697(83)90418-9. [DOI] [PubMed] [Google Scholar]
- Gubler U., Hoffman B. J. A simple and very efficient method for generating cDNA libraries. Gene. 1983 Nov;25(2-3):263–269. doi: 10.1016/0378-1119(83)90230-5. [DOI] [PubMed] [Google Scholar]
- Hieter P. A., Hollis G. F., Korsmeyer S. J., Waldmann T. A., Leder P. Clustered arrangement of immunoglobulin lambda constant region genes in man. Nature. 1981 Dec 10;294(5841):536–540. doi: 10.1038/294536a0. [DOI] [PubMed] [Google Scholar]
- Holers V. M., Seya T., Brown E., O'Shea J. J., Atkinson J. P. Structural and functional studies on the human C3b/C4b receptor (CR1) purified by affinity chromatography using a monoclonal antibody. Complement. 1986;3(2):63–78. doi: 10.1159/000467882. [DOI] [PubMed] [Google Scholar]
- Kant J. A., Fornace A. J., Jr, Saxe D., Simon M. I., McBride O. W., Crabtree G. R. Evolution and organization of the fibrinogen locus on chromosome 4: gene duplication accompanied by transposition and inversion. Proc Natl Acad Sci U S A. 1985 Apr;82(8):2344–2348. doi: 10.1073/pnas.82.8.2344. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kristensen T., Wetsel R. A., Tack B. F. Structural analysis of human complement protein H: homology with C4b binding protein, beta 2-glycoprotein I, and the Ba fragment of B2. J Immunol. 1986 May 1;136(9):3407–3411. [PubMed] [Google Scholar]
- Lathe R. Synthetic oligonucleotide probes deduced from amino acid sequence data. Theoretical and practical considerations. J Mol Biol. 1985 May 5;183(1):1–12. doi: 10.1016/0022-2836(85)90276-1. [DOI] [PubMed] [Google Scholar]
- Lublin D. M., Griffith R. C., Atkinson J. P. Influence of glycosylation on allelic and cell-specific Mr variation, receptor processing, and ligand binding of the human complement C3b/C4b receptor. J Biol Chem. 1986 May 5;261(13):5736–5744. [PubMed] [Google Scholar]
- Maeda N., Yang F., Barnett D. R., Bowman B. H., Smithies O. Duplication within the haptoglobin Hp2 gene. Nature. 1984 May 10;309(5964):131–135. doi: 10.1038/309131a0. [DOI] [PubMed] [Google Scholar]
- Nickells M. W., Seya T., Holers V. M., Atkinson J. P. Analysis of C3b/C4b receptor (CR1) polymorphic variants by tryptic peptide mapping. Mol Immunol. 1986 Jun;23(6):661–668. doi: 10.1016/0161-5890(86)90104-5. [DOI] [PubMed] [Google Scholar]
- Park I., Schaeffer E., Sidoli A., Baralle F. E., Cohen G. N., Zakin M. M. Organization of the human transferrin gene: direct evidence that it originated by gene duplication. Proc Natl Acad Sci U S A. 1985 May;82(10):3149–3153. doi: 10.1073/pnas.82.10.3149. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rodriguez de Cordoba S., Lublin D. M., Rubinstein P., Atkinson J. P. Human genes for three complement components that regulate the activation of C3 are tightly linked. J Exp Med. 1985 May 1;161(5):1189–1195. doi: 10.1084/jem.161.5.1189. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sanger F., Nicklen S., Coulson A. R. DNA sequencing with chain-terminating inhibitors. Proc Natl Acad Sci U S A. 1977 Dec;74(12):5463–5467. doi: 10.1073/pnas.74.12.5463. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shen S. H., Slightom J. L., Smithies O. A history of the human fetal globin gene duplication. Cell. 1981 Oct;26(2 Pt 2):191–203. doi: 10.1016/0092-8674(81)90302-0. [DOI] [PubMed] [Google Scholar]
- Sim R. B. Large-scale isolation of complement receptor type 1 (CR1) from human erythrocytes. Proteolytic fragmentation studies. Biochem J. 1985 Dec 15;232(3):883–889. doi: 10.1042/bj2320883. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Southern E. M. Detection of specific sequences among DNA fragments separated by gel electrophoresis. J Mol Biol. 1975 Nov 5;98(3):503–517. doi: 10.1016/s0022-2836(75)80083-0. [DOI] [PubMed] [Google Scholar]
- Weis J. J., Fearon D. T., Klickstein L. B., Wong W. W., Richards S. A., de Bruyn Kops A., Smith J. A., Weis J. H. Identification of a partial cDNA clone for the C3d/Epstein-Barr virus receptor of human B lymphocytes: homology with the receptor for fragments C3b and C4b of the third and fourth components of complement. Proc Natl Acad Sci U S A. 1986 Aug;83(15):5639–5643. doi: 10.1073/pnas.83.15.5639. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wong W. W., Jack R. M., Smith J. A., Kennedy C. A., Fearon D. T. Rapid purification of the human C3b/C4b receptor (CR1) by monoclonal antibody affinity chromatography. J Immunol Methods. 1985 Oct 10;82(2):303–313. doi: 10.1016/0022-1759(85)90362-x. [DOI] [PubMed] [Google Scholar]
- Wong W. W., Klickstein L. B., Smith J. A., Weis J. H., Fearon D. T. Identification of a partial cDNA clone for the human receptor for complement fragments C3b/C4b. Proc Natl Acad Sci U S A. 1985 Nov;82(22):7711–7715. doi: 10.1073/pnas.82.22.7711. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wong W. W., Wilson J. G., Fearon D. T. Genetic regulation of a structural polymorphism of human C3b receptor. J Clin Invest. 1983 Aug;72(2):685–693. doi: 10.1172/JCI111018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wozney J., Hanahan D., Tate V., Boedtker H., Doty P. Structure of the pro alpha 2 (I) collagen gene. Nature. 1981 Nov 12;294(5837):129–135. doi: 10.1038/294129a0. [DOI] [PubMed] [Google Scholar]