Small Mannose-binding Lectin-associated Protein Plays a Regulatory Role in the Lectin Complement Pathway.
From: Department of Immunology, Fukushima Medical University, 1-Hikariga-oka, Fukushima City 960-1295, Japan.
Journal of immunology (Baltimore, Md. : 1950)
- Publish Date: Dec 2006
- ISSN: 0022-1767
- Volume: 177
- Issue: 12
- Pages: 8626-32
- Medium: Print
- Language: English
- Citation (JAMA): Iwaki Daisuke, Kanno Kazuko, Takahashi Minoru, et al. Small Mannose-binding Lectin-associated Protein Plays a Regulatory Role in the Lectin Complement Pathway.. J. Immunol. Dec 2006;177:8626-32
Abstract
Mannose-binding lectin (MBL) and ficolins are pattern recognition proteins acting in innate immunity, and they trigger the activation of the lectin complement pathway through MBL-associated serine proteases (MASPs). Upon activation of the lectin pathway, MASP-2 cleaves C4 and C2. A truncated form of MASP-2, named small MBL-associated protein (sMAP), is also associated with MBL/ficolin-MASP complexes. To clarify the role of sMAP, we have generated sMAP-deficient (sMAP(-/-)) mice by targeted disruption of the sMAP-specific exon. Because of the gene disruption, the expression level of MASP-2 was also decreased in sMAP(-/-) mice. When recombinant sMAP (rsMAP) and recombinant MASP-2 (rMASP-2) reconstituted the MBL-MASP-sMAP complex in deficient serum, the binding of these recombinant proteins to MBL was competitive, and the C4 cleavage activity of the MBL-MASP-sMAP complex was restored by the addition of rMASP-2, whereas the addition of rsMAP attenuated the activity. Therefore, MASP-2 is essential for the activation of C4 and sMAP plays a regulatory role in the activation of the lectin pathway.
Mesh Headings (Keywords): Animals, Complement C4, Complement Pathway, Mannose-Binding Lectin, Hydrolysis, Immunity, Natural, Mannose-Binding Lectin, Mannose-Binding Protein-Associated Serine Proteases, Mice, Multiprotein Complexes
Check for Full Text / PubMed Unique Identifier (PMID): 17142762
This abstract is part of PubMed, a service of the U.S. National Library of Medicine. PubMed includes more than 17 million citations from MEDLINE and other life science journals for biomedical articles. See Copyright and Disclaimers.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PubMed document.
The data herein was last updated on July 8th, 2008 and may not reflect the most current and accurate data available from NLM.