Abstract
The lectin pathway of complement is considered to be the most ancient complement pathway as inferred from identification of ancient homologs of mannose-binding lectin (MBL) and MBL-associated serine proteases (MASPs) in some invertebrates. MBL homologs with galactose selectivity and an MASP3-like sequence also occur in bony fish, linking the evolution of the lectin complement pathway from invertebrates to higher vertebrates. However, these cannot be considered authentic complement components until confirmatory functional evidence is obtained. Here, we report the isolation and characterization of two MBL homologs from a cyprinid teleost, the common carp, Cyprinus carpio. One, designated GalBL, corresponds to the MBL-like molecule with the galactose specificity. The other is an authentic MBL with mannose specificity. Both were found to associate with a serine protease that cleaves native human C4 into C4b but not C4i with a hydrolyzed thioester. Molecular cloning and phylogenetic analysis revealed this C4-activating protease to be carp MASP2, indicating that MASP2 arose before the emergence of bony fish. Database mining of MBL-like genes reveals that MBL and GalBL genes are arranged in tandem in the zebrafish genome and that both lectins are conserved in the distantly related puffer fish. These results imply that bony fish have developed a diverged set of MBL homologs that function in the lectin complement pathway.
| Original language | English |
|---|---|
| Pages (from-to) | 5471-5479 |
| Number of pages | 9 |
| Journal | Journal of Immunology |
| Volume | 177 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - Oct 15 2006 |
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All Science Journal Classification (ASJC) codes
- Immunology and Allergy
- Immunology
Cite this
Lectin pathway of bony fish complement : Identification of two homologs of the mannose-binding lectin associated with MASP2 in the common carp (Cyprinus carpio). / Nakao, Miki; Kajiya, Takayuki; Sato, Yuho; Somamoto, Tomonori; Kato-Unoki, Yoko; Matsushita, Misao; Nakata, Munehiro; Fujita, Teizo; Yano, Tomoki.
In: Journal of Immunology, Vol. 177, No. 8, 15.10.2006, p. 5471-5479.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Lectin pathway of bony fish complement
T2 - Identification of two homologs of the mannose-binding lectin associated with MASP2 in the common carp (Cyprinus carpio)
AU - Nakao, Miki
AU - Kajiya, Takayuki
AU - Sato, Yuho
AU - Somamoto, Tomonori
AU - Kato-Unoki, Yoko
AU - Matsushita, Misao
AU - Nakata, Munehiro
AU - Fujita, Teizo
AU - Yano, Tomoki
PY - 2006/10/15
Y1 - 2006/10/15
N2 - The lectin pathway of complement is considered to be the most ancient complement pathway as inferred from identification of ancient homologs of mannose-binding lectin (MBL) and MBL-associated serine proteases (MASPs) in some invertebrates. MBL homologs with galactose selectivity and an MASP3-like sequence also occur in bony fish, linking the evolution of the lectin complement pathway from invertebrates to higher vertebrates. However, these cannot be considered authentic complement components until confirmatory functional evidence is obtained. Here, we report the isolation and characterization of two MBL homologs from a cyprinid teleost, the common carp, Cyprinus carpio. One, designated GalBL, corresponds to the MBL-like molecule with the galactose specificity. The other is an authentic MBL with mannose specificity. Both were found to associate with a serine protease that cleaves native human C4 into C4b but not C4i with a hydrolyzed thioester. Molecular cloning and phylogenetic analysis revealed this C4-activating protease to be carp MASP2, indicating that MASP2 arose before the emergence of bony fish. Database mining of MBL-like genes reveals that MBL and GalBL genes are arranged in tandem in the zebrafish genome and that both lectins are conserved in the distantly related puffer fish. These results imply that bony fish have developed a diverged set of MBL homologs that function in the lectin complement pathway.
AB - The lectin pathway of complement is considered to be the most ancient complement pathway as inferred from identification of ancient homologs of mannose-binding lectin (MBL) and MBL-associated serine proteases (MASPs) in some invertebrates. MBL homologs with galactose selectivity and an MASP3-like sequence also occur in bony fish, linking the evolution of the lectin complement pathway from invertebrates to higher vertebrates. However, these cannot be considered authentic complement components until confirmatory functional evidence is obtained. Here, we report the isolation and characterization of two MBL homologs from a cyprinid teleost, the common carp, Cyprinus carpio. One, designated GalBL, corresponds to the MBL-like molecule with the galactose specificity. The other is an authentic MBL with mannose specificity. Both were found to associate with a serine protease that cleaves native human C4 into C4b but not C4i with a hydrolyzed thioester. Molecular cloning and phylogenetic analysis revealed this C4-activating protease to be carp MASP2, indicating that MASP2 arose before the emergence of bony fish. Database mining of MBL-like genes reveals that MBL and GalBL genes are arranged in tandem in the zebrafish genome and that both lectins are conserved in the distantly related puffer fish. These results imply that bony fish have developed a diverged set of MBL homologs that function in the lectin complement pathway.
UR - http://www.scopus.com/inward/record.url?scp=33749525326&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33749525326&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.177.8.5471
DO - 10.4049/jimmunol.177.8.5471
M3 - Article
C2 - 17015733
AN - SCOPUS:33749525326
VL - 177
SP - 5471
EP - 5479
JO - Journal of Immunology
JF - Journal of Immunology
SN - 0022-1767
IS - 8
ER -