Gene Symbol: Masp1
Description: mannan-binding lectin serine peptidase 1
Alias: Masp1/3, Masp3, mannan-binding lectin serine protease 1, MASP-1, complement factor MASP-3, complement-activating component of Ra-reactive factor, mannan-binding lectin serine protease 2-like, mannose-binding lectin-associated serine protease 1, mannose-binding protein associated serine protease-1, mannose-binding protein-associated serine protease, ra-reactive factor serine protease p100, raRF, serine protease 5, serine protease MASP1
Species: rat
Products:     Masp1

Top Publications

  1. Ambrus G, Gal P, Kojima M, Szilágyi K, Balczer J, Antal J, et al. Natural substrates and inhibitors of mannan-binding lectin-associated serine protease-1 and -2: a study on recombinant catalytic fragments. J Immunol. 2003;170:1374-82 pubmed
    ..Nevertheless, relative rates of reaction with alpha-2-macroglobulin and C1-inhibitor suggest that alpha-2-macroglobulin may be a significant physiological inhibitor of MASP-1. ..
  2. Gingras A, Girija U, Keeble A, Panchal R, Mitchell D, Moody P, et al. Structural basis of mannan-binding lectin recognition by its associated serine protease MASP-1: implications for complement activation. Structure. 2011;19:1635-43 pubmed publisher
    ..The structural insights reveal a new focus for inhibitors and we have validated this concept by targeting the binding pocket of the MASP. ..
  3. Nan R, Furze C, Wright D, Gor J, Wallis R, Perkins S. Flexibility in Mannan-Binding Lectin-Associated Serine Proteases-1 and -2 Provides Insight on Lectin Pathway Activation. Structure. 2017;25:364-375 pubmed publisher
    ..We conclude that MASP-1 and MASP-2 are flexible at multiple sites and that this flexibility may permit both intra- and inter-complex activation. ..
  4. Knittel T, Fellmer P, Neubauer K, Kawakami M, Grundmann A, Ramadori G. The complement-activating protease P100 is expressed by hepatocytes and is induced by IL-6 in vitro and during the acute phase reaction in vivo. Lab Invest. 1997;77:221-30 pubmed
  5. Wallis R, Dodd R. Interaction of mannose-binding protein with associated serine proteases: effects of naturally occurring mutations. J Biol Chem. 2000;275:30962-9 pubmed
    ..Analysis of MASP binding by rat MBP containing naturally occurring mutations equivalent to those associated with human immunodeficiency indicates that binding to both truncated MASP-1 and MASP-2 proteins is defective in such mutants. ..
  6. Matsushita M, Thiel S, Jensenius J, Terai I, Fujita T. Proteolytic activities of two types of mannose-binding lectin-associated serine protease. J Immunol. 2000;165:2637-42 pubmed
    ..C2 was activated by both MASPs. C1 inhibitor (C1 INH), an inhibitor for C1r and C1s, formed equimolar complexes with MASP-1 and MASP-2 and inhibited their proteolytic activities. ..
  7. Dahl M, Thiel S, Matsushita M, Fujita T, Willis A, Christensen T, et al. MASP-3 and its association with distinct complexes of the mannan-binding lectin complement activation pathway. Immunity. 2001;15:127-35 pubmed
    ..MASP-1, MAp19, and direct C3-cleaving activity are associated with smaller oligomers whereas MASP-3 is found together with MASP-2 on larger oligomers. MASP-3 downregulate the C4 and C2 cleaving activity of MASP-2. ..
  8. Cseh S, Vera L, Matsushita M, Fujita T, Arlaud G, Thielens N. Characterization of the interaction between L-ficolin/p35 and mannan-binding lectin-associated serine proteases-1 and -2. J Immunol. 2002;169:5735-43 pubmed
    ..Preincubation of the MASPs with soluble MBL inhibited subsequent binding to immobilized L-ficolin/P35 and, conversely, suggesting that these lectins compete with each other for binding to the MASPs in vivo. ..
  9. Stover C, Lynch N, Dahl M, Hanson S, Takahashi M, Frankenberger M, et al. Murine serine proteases MASP-1 and MASP-3, components of the lectin pathway activation complex of complement, are encoded by a single structural gene. Genes Immun. 2003;4:374-84 pubmed
    ..Furthermore, we demonstrate the evolutionary conservation of MASP-3 mRNA in cDNA transcripts from guinea pig, rabbit, pufferfish, and cow. ..

More Information


  1. Chen C, Wallis R. Two mechanisms for mannose-binding protein modulation of the activity of its associated serine proteases. J Biol Chem. 2004;279:26058-65 pubmed
    ..MASP-1 cleaves C2 almost as efficiently as MASP-2 does, but it does not cleave C4. Thus MASP-1 probably enhances complement activation triggered by MBP.MASP-2 complexes, but it cannot initiate activation itself. ..
  2. Møller Kristensen M, Thiel S, Sjoholm A, Matsushita M, Jensenius J. Cooperation between MASP-1 and MASP-2 in the generation of C3 convertase through the MBL pathway. Int Immunol. 2007;19:141-9 pubmed
  3. Teillet F, Gaboriaud C, Lacroix M, Martin L, Arlaud G, Thielens N. Crystal structure of the CUB1-EGF-CUB2 domain of human MASP-1/3 and identification of its interaction sites with mannan-binding lectin and ficolins. J Biol Chem. 2008;283:25715-24 pubmed publisher
    MASP-1 and MASP-3 are homologous proteases arising from alternative splicing of the MASP1/3 gene. They include an identical CUB(1)-EGF-CUB(2)-CCP(1)-CCP(2) module array prolonged by different serine protease domains at the C-terminal end...
  4. Rossi V, Cseh S, Bally I, Thielens N, Jensenius J, Arlaud G. Substrate specificities of recombinant mannan-binding lectin-associated serine proteases-1 and -2. J Biol Chem. 2001;276:40880-7 pubmed
    ..In view of the very low activity of MASP-1 on C3 and C2, our data raise questions about the implication of this protease in complement activation. ..
  5. Takahashi M, Iwaki D, Kanno K, Ishida Y, Xiong J, Matsushita M, et al. Mannose-binding lectin (MBL)-associated serine protease (MASP)-1 contributes to activation of the lectin complement pathway. J Immunol. 2008;180:6132-8 pubmed
    ..In this study, a MASP-1- and MASP-3-deficient mouse model (MASP1/3(-/-)) was generated by a gene targeting strategy to investigate the roles of MASP-1 and MASP-3 in the lectin ..