cDNA cloning, sequencing and chromosomal assignment of the gene for mouse complement factor I (C3b/C4b inactivator): identification of a species specific divergent segment in factor I
| Autor: | Lisa M. Kunnath-Muglia, Joe O. Minta, Gabriel Goldberger, Michael J. Wong, Christine A. Kozak |
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| Rok vydání: | 1996 |
| Předmět: |
Male
DNA Complementary Protein subunit Immunology Molecular Sequence Data Xenopus Gene Expression Complement factor I Biology Mice Xenopus laevis D-segment Species Specificity Complementary DNA Sequence Homology Nucleic Acid Complement C3b Inactivator Proteins Animals Humans Amino Acid Sequence RNA Messenger Cloning Molecular Molecular Biology Gene Genetics Mice Inbred BALB C Base Sequence Sequence Homology Amino Acid Protein primary structure Chromosome Mapping biology.organism_classification Molecular biology Complement system Complement Factor I Female Chickens Sequence Alignment |
| Zdroj: | Molecular immunology. 33(1) |
| ISSN: | 0161-5890 |
| Popis: | Factor I is an essential regulatory serine proteinase of the complement cascade. It cleaves and inactivates the C3b and C4b constituents of the C3 and C5 convertases and thereby regulates many complement-mediated activities. The human proteins is a heterodimer composed of a 50 kDa non-catalytic subunit (which contains serveral domains, i.e. FIM, CD5, LDLr type A) disulfide linked to a 38 kDa catalytic subunit. Recent characterization of Xenopus factor I cDNA revealed a 29 residue negatively charged region in its heavy chain which is absent in the human protein (Kunnath-Muglia et al., Molec. Immun. 30, 1249–1256, 1993). We report the complete cDNA sequence of mouse factor I as well as a partial chicken factor I cDNA sequence. Alignment of these two sequences with the published sequences for human and Xenopus proteins (a) demonstrates an overall conservation of primary structure and domain organization of mouse factor I, and (b) defines a divergent segment (D segment) in each species. In Xenopus protein, the D segment includes the 29 residue negatively charged region. In each of the four species examined, the D segment differed in length, sequence, organization, and number of repeated subregions. These differences reflect a considerable evolution of D segment. The significance of the diversity of the D segment is at present unclear. We also report the chromosomal localization of the mouse factor I gene (Cfi) to distal chromosome 3 near Egf. |
| Databáze: | OpenAIRE |
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