MASP1 (protein)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Mannan-binding lectin serine peptidase 1 (C4/C2 activating component of Ra-reactive factor)
Available structures
PDB Ortholog search: PDBe, RCSB
Symbols MASP1 ; 3MC1; CRARF; CRARF1; MAP1; MASP; MASP3; MAp44; PRSS5; RaRF
External IDs OMIM600521 HomoloGene89143 GeneCards: MASP1 Gene
EC number 3.4.21.-
Species Human Mouse
Entrez 5648 n/a
Ensembl ENSG00000127241 n/a
UniProt P48740 n/a
RefSeq (mRNA) NM_001031849 n/a
RefSeq (protein) NP_001027019 n/a
Location (UCSC) Chr 3:
186.94 – 187.01 Mb
PubMed search [1] n/a

Mannan-binding lectin serine protease 1 also known as mannose-associated serine protease 1 (MASP-1) is an enzyme that in humans is encoded by the MASP1 gene.[1][2][3]

MASP-1 is involved in the lectin pathway of the complement system and is responsible for cleaving C4 and C2 to form C4b2b, a C3-convertase.[4]


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.[3]

See also[edit]


  1. ^ 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. PMID 8240317. 
  2. ^ 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. PMID 8018603. 
  3. ^ a b "Entrez Gene: mannan-binding lectin serine peptidase 1 (C4/C2 activating component of Ra-reactive factor)". 
  4. ^ Matsushita M, Thiel S, Jensenius JC, Terai I, Fujita T (1 September 2000). "Proteolytic activities of two types of mannose-binding lectin-associated serine protease". J. Immunol. 165 (5): 2637–42. doi:10.4049/jimmunol.165.5.2637. PMID 10946292. 

Further reading[edit]

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.