MASP-1 is a serine protease that functions as a component of the lectin pathway of complement activation. The complement pathway plays an essential role in the innate and adaptive immune response. MASP-1 is synthesized as a zymogen and is activated when it complexes with the pathogen recognition molecules of lectin pathway, the mannose-binding lectin and the ficolins. This protein is not directly involved in complement activation but may play a role as an amplifier of complement activation by cleaving complement C2 or by activating another complement serine protease, MASP-2. MASP-1 is also able to cleave fibrinogen and factor XIII and may be involved in coagulation. A splice variant of this gene which lacks the serine protease domain functions as an inhibitor of the complement pathway.
^Takada F, Takayama Y, Hatsuse H, Kawakami M (October 1993). "A new member of the C1s family of complement proteins found in a bactericidal factor, Ra-reactive factor, in human serum". Biochem. Biophys. Res. Commun.196 (2): 1003–9. doi:10.1006/bbrc.1993.2349. PMID8240317.
^Sato T, Endo Y, Matsushita M, Fujita T (April 1994). "Molecular characterization of a novel serine protease involved in activation of the complement system by mannose-binding protein". Int. Immunol.6 (4): 665–9. doi:10.1093/intimm/6.4.665. PMID8018603.
Dobó J, Harmat V, Beinrohr L, Sebestyén E, Závodszky P, Gál P (2009). "MASP-1, a promiscuous complement protease: structure of its catalytic region reveals the basis of its broad specificity.". J. Immunol.183 (2): 1207–14. doi:10.4049/jimmunol.0901141. PMID19564340.
Kocsis A, Kékesi KA, Szász R, Végh BM, Balczer J, Dobó J, Závodszky P, Gál P, Pál G (2010). "Selective inhibition of the lectin pathway of complement with phage display selected peptides against mannose-binding lectin-associated serine protease (MASP)-1 and -2: significant contribution of MASP-1 to lectin pathway activation.". J. Immunol.185 (7): 4169–78. doi:10.4049/jimmunol.1001819. PMID20817870.
Megyeri M, Makó V, Beinrohr L, Doleschall Z, Prohászka Z, Cervenak L, Závodszky P, Gál P (2009). "Complement protease MASP-1 activates human endothelial cells: PAR4 activation is a link between complement and endothelial function.". J. Immunol.183 (5): 3409–16. doi:10.4049/jimmunol.0900879. PMID19667088.
Skjoedt MO, Palarasah Y, Munthe-Fog L, Jie Ma Y, Weiss G, Skjodt K, Koch C, Garred P (2010). "MBL-associated serine protease-3 circulates in high serum concentrations predominantly in complex with Ficolin-3 and regulates Ficolin-3 mediated complement activation.". Immunobiology215 (11): 921–31. doi:10.1016/j.imbio.2009.10.006. PMID19939495.
Degn SE, Hansen AG, Steffensen R, Jacobsen C, Jensenius JC, Thiel S (2009). "MAp44, a human protein associated with pattern recognition molecules of the complement system and regulating the lectin pathway of complement activation.". J. Immunol.183 (11): 7371–8. doi:10.4049/jimmunol.0902388. PMID19917686.
Ennis S, Jomary C, Mullins R, Cree A, Chen X, Macleod A, Jones S, Collins A, Stone E, Lotery A (2008). "Association between the SERPING1 gene and age-related macular degeneration: a two-stage case-control study.". Lancet372 (9652): 1828–34. doi:10.1016/S0140-6736(08)61348-3. PMID18842294.
Duus K, Thielens NM, Lacroix M, Tacnet P, Frachet P, Holmskov U, Houen G (2010). "CD91 interacts with mannan-binding lectin (MBL) through the MBL-associated serine protease-binding site.". FEBS J.277 (23): 4956–64. doi:10.1111/j.1742-4658.2010.07901.x. PMID21054788.
Degn SE, Jensen L, Gál P, Dobó J, Holmvad SH, Jensenius JC, Thiel S (2010). "Biological variations of MASP-3 and MAp44, two splice products of the MASP1 gene involved in regulation of the complement system.". J. Immunol. Methods361 (1-2): 37–50. doi:10.1016/j.jim.2010.07.006. PMID20673767.