First Author | Nonaka M | Year | 1984 |
Journal | Proc Natl Acad Sci U S A | Volume | 81 |
Issue | 21 | Pages | 6822-6 |
PubMed ID | 6208559 | Mgi Jnum | J:7633 |
Mgi Id | MGI:56102 | Doi | 10.1073/pnas.81.21.6822 |
Citation | Nonaka M, et al. (1984) Isolation of cDNA clones specifying the fourth component of mouse complement and its isotype, sex-limited protein. Proc Natl Acad Sci U S A 81(21):6822-6 |
abstractText | cDNA clones specific for the fourth component of mouse complement (C4) and its hormonally regulated isotype, sex-linked protein (Slp), were isolated using as a probe a 20-mer synthetic oligonucleotide corresponding to a known sequence of human C4 cDNA. Two types of clones, one specific for C4 (pFC4/10, with a 3.7 kilobase insert) and one specific for Slp (pFSlp/1, with a 4.7 kilobase insert), were isolated from liver cDNA libraries constructed from the Slp-producing FM mouse strain. The cDNA inserts of these clones shared 70% of the restriction sites determined. Only one type of clone was isolated from the Slp-negative DBA/1 strain; this type showed restriction maps indistinguishable from that of pFC4/10. pFC4/10 and pFSlp/1 displayed extensive homology: 94% nucleotide homology and 89% derived amino acid homology in the C4a region and 92% nucleotide homology and 89% derived amino acid homology in the thiol-ester region. An Arg-Gln-Lys-Arg sequence in the beta-alpha junction and a Cys-Ala-Glu-Gln sequence in the thiol-ester site were identified for both proteins. A remarkable divergency between C4 and Slp sequences was recognized in the region immediately following the C4a sequence. |