Cloning and characterization of novel ficolins from the solitary ascidian,Halocynthia roretzi

Citation
A. Kenjo et al., Cloning and characterization of novel ficolins from the solitary ascidian,Halocynthia roretzi, J BIOL CHEM, 276(23), 2001, pp. 19959-19965
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Biochemistry & Biophysics
Journal title
JOURNAL OF BIOLOGICAL CHEMISTRY
ISSN journal
0021-9258 → ACNP
Volume
276
Issue
23
Year of publication
2001
Pages
19959 - 19965
Database
ISI
SICI code
0021-9258(20010608)276:23<19959:CACONF>2.0.ZU;2-Y
Abstract
Ficolins are animal lectins with collagen-like and fibrinogen-like domains. They are involved in the first line of host defense against pathogens. Hum an ficolin/P35 as well as mannose-binding lectin (MBL) activates the comple ment lectin pathway in association with MEL-associated serine proteases. To elucidate the origin and evolution of ficolins, we separated similar to 40 kDa (p40) and similar to 50 kDa (p50) N-acetylglucosamine-binding lectins from hemolymph plasma of the solitary ascidian. Binding assays revealed tha t p40 recognizes N-acetyl groups in association with a pyranose ring and th at p50 recognizes N-acetylglucosamine alone. Based on the amino acid sequen ces of the proteins, we isolated two clones each of p40 and p50 from the as cidian hepatopancreas cDNA and determined the entire coding sequences of th ese clones. Because all of the clones contained both collagen-like and fibr inogen-like domains, we concluded that these were homologs of the mammalian ficolin family and designated ascidian ficolins (AsFCNs), The fibrinogen-l ike domain of the AsFCNs shows 45.4-52.4% amino acid sequence identity with the mammalian ficolin family. A phylogenetic tree of the fibrinogen-like s equences shows that all the fibrinogen-like domains may have evolved from a common ancestor that branched off an authentic fibrinogen. These results s uggest that AsFCNs play an important role with respect to ascidian hemolymp h lectin activity and the correlation of different functions with binding s pecificity.