The role of MASP-1/3 in complement activation.
Adv Exp Med Biol
; 735: 41-53, 2013.
Article
in En
| MEDLINE
| ID: mdl-23402018
ABSTRACT
The complement system, which consists of more than 30 plasma and cell surface proteins, is activated by three pathways the classical, lectin, and alternative pathways, leading to the generation of opsonins and pathogen destruction. In the lectin pathway, mannose-binding lectin (MBL) and ficolins act as pattern recognition molecules for pathogens, resulting in the activation of MBL-associated serine proteases (MASPs MASP-1, MASP-2, and MASP-3). Among these proteases, MASP-2 is a key enzyme that cleaves C4 and C2 to assemble a C3 convertase (C4b2a). However, the physiological function of MASP-1 and MASP-3 remains unclear. To investigate the roles of MASP-1 and MASP-3, we generated a MASP-1- and MASP-3-deficient (M1/3 KO) mouse model and found that the deficient mice lacked alternative pathway activation because factor D (Df) remained as a proenzyme in the serum. MASP-1 and MASP-3 were able to convert the proenzyme of Df to an active form in vitro. In addition, MASP-1 was able to activate MASP-2 and MASP-3 as C1r activates C1s. Thus, MASP-1 and MASP-3 seem to be involved in activation of both the lectin and alternative pathways.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Complement Activation
/
Mannose-Binding Protein-Associated Serine Proteases
Type of study:
Prognostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Adv Exp Med Biol
Year:
2013
Type:
Article
Affiliation country:
Japan