Protein Domain : IPR024175

Type:  Family Name:  Peptidase S1A, complement C1r/C1S/mannan-binding
Description:  These proteins belong to MEROPS peptidase family S1 (chymotrypsin family, clan PA(S)), subfamily S1A.This family contains the mammalian mannan-binding lectin-associated serine proteases 1 and 2 (MASP1 and MASP2) and complement components C1s and C1r. The C1 complex, containing C1q, C1s, and C1r, triggers the classical complement pathway. When C1q interacts with antibody, C1r becomes autocatalytically activated. Activated C1r in turn activates C1s, which then cleaves C2 and C4 in the classical pathway.Mannose-binding lectin (MBL) complexes with MASP1, MASP2, and a smaller alternative splice product of the MASP2 gene. Binding of MBL to carbohydrates on the surface of microorganisms triggers activation of the associated MASPs. Then MASP1 activates C3 and C2, whereas MASP2 activates C4 and C2 []. Based on the fact that the gene structures of MASP1, C1r, and C1s are similar except that C1r and C1s lack introns in the region encoding the trypsin domain, it has been proposed that the MASP proteins evolved earlier than C1r and C1s [].These sequences typically contain a signal sequence, followed by a CUB domain, an EGF-like domain (which often is not detected), a second CUB domain, two sushi domains (sometimes only one is detected), and a trypsin domain. Short Name:  Pept_S1A_C1r/C1S/mannan-bd

0 Child Features

0 Contains

1 Cross References

Identifier
PIRSF001155

0 Found In

3 GO Annotations

GO Term Gene Name
GO:0004252 IPR024175
GO:0006956 IPR024175
GO:0005576 IPR024175

3 Ontology Annotations

GO Term Gene Name
GO:0004252 IPR024175
GO:0006956 IPR024175
GO:0005576 IPR024175

1 Parent Features

DB identifier Type Name
IPR001314 Family Peptidase S1A, chymotrypsin-type

0 Proteins

2 Publications

First Author Title Year Journal Volume Pages PubMed ID
            10946292
            10475605