Murine serine proteases MASP-1 and MASP-3, components of the lectin pathway activation complex of complement, are encoded by a single structural gene.
Activation of the lectin pathway of complement is initiated by the binding to microbial carbohydrate structures of a multimolecular fluid-phase complex composed of a carbohydrate recognition subcomponent that associates with three specific serine proteases and an enzymatically inert protein of 19 kDa. The first carbohydrate recognition subcomponent of the lectin pathway identified was mannan-binding lectin (MBL), hence the serine proteases were named MBL-associated serine proteases (MASPs) and numbered according to the sequence of their discovery. Here we describe the primary structures of the two distinct serine proteases MASP-1 and MASP-3 in the rat (and of MASP-3 in the mouse), show their association with plasma MBL complexes, and demonstrate that in rat and mouse, as in man, MASP-1 and MASP-3 are encoded by a single structural gene. For both species, we present the genomic region and regulatory elements responsible for the processing of either MASP-1 or MASP-3 mRNA by alternative splicing/alternative polyadenylation. Furthermore, we demonstrate the evolutionary conservation of MASP-3 mRNA in cDNA transcripts from guinea pig, rabbit, pufferfish, and cow.
Stover
C M
CM
Department of Microbiology and Immunology, University of Leicester, UK.
Lynch
N J
NJ
Dahl
M R
MR
Hanson
S
S
Takahashi
M
M
Frankenberger
M
M
Ziegler-Heitbrock
L
L
Eperon
I
I
Thiel
S
S
Schwaeble
W J
WJ
D017398:Alternative Splicing / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D037582:Complement Pathway, Mannose-Binding Lectin / Q000235:genetics*; D017124:Conserved Sequence / Q000235:genetics; D017931:DNA Primers; D018076:DNA, Complementary / Q000235:genetics; D050606:Mannose-Binding Protein-Associated Serine Proteases; D051379:Mice / Q000235:genetics*; D015336:Molecular Probe Techniques; D008969:Molecular Sequence Data; D026723:Polyadenylation / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats / Q000235:genetics*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012697:Serine Endopeptidases / Q000235:genetics* / Q000378:metabolism
D017931:DNA Primers; D018076:DNA, Complementary; D012333:RNA, Messenger; C468572:MASP-3 protein, mouse; D050606:Mannose-Binding Protein-Associated Serine Proteases; D012697:Serine Endopeptidases