| First Author | Nakao M | Year | 2003 |
| Journal | Immunogenetics | Volume | 54 |
| Issue | 11 | Pages | 801-6 |
| PubMed ID | 12618913 | Mgi Jnum | J:83002 |
| Mgi Id | MGI:2656444 | Doi | 10.1007/s00251-002-0518-9 |
| Citation | Nakao M, et al. (2003) Molecular cloning of the complement regulatory factor I isotypes from the common carp (Cyprinus carpio). Immunogenetics 54(11):801-6 |
| abstractText | Factor I is a novel serine protease that regulates complement activation. Here we report the complete primary structure of two isotypic factor Is isolated from the common carp ( Cyprinus carpio), a pseudotetraploid teleost. A carp hepatopancreas cDNA library was screened using two RT-PCR-amplified cDNA fragments encoding part of the carp factor I-like serine protease domain. Two distinct cDNA clones, designated FI-A and FI-B, were isolated. Their deduced amino acid sequences share 75.2% identity with each other. FI-A has a typical factor I-like domain organization composed of two disulfide-linked polypeptides (H-chain and L-chain). On the other hand, FI-B contains a novel sequence of 115 amino acids inserted at the N-terminus of the H-chain. Genomic Southern hybridization suggests that FI-A and FI-B are encoded by distinct genes in the carp genome. Expression analysis by RT-PCR revealed that the major site of FI-A expression is the ovary, whereas FI-B expression is detected mainly in the hepatopancreas at a level higher than that of FI-A. The present data, taken together, suggest that carp have duplicated genes coding for factor I, and FI-B with the novel insertion plays a dominant role in the complement system. In addition, homology search of the fugu genome database using the carp FI-A and FI-B sequences identified a putative fugu factor I gene, which has an exon/intron organization different from that of the human orthologue. |
