Map44

{{protein

| Name = mannan-binding lectin serine peptidase 1 (C4/C2 activating component of Ra-reactive factor)

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| HGNCid = 6901

| Symbol = MASP1

| AltSymbols = CRARF, PRSS5

| EntrezGene = 5648

| OMIM = 600521

| RefSeq = NM_001879

| UniProt = P48740

| PDB =

| ECnumber =

| Chromosome = 3

| Arm = q

| Band = 27

| LocusSupplementaryData = -q28

}}

Mannose-binding lectin-associated protein of 44 kDa (MAp44) is a protein arising from the human MASP1 gene. MASP-1, MASP-3 and MAp44 are alternative splice products of the MASP1 gene. MAp44 has been suggested to act as a competitive inhibitor of lectin pathway activation, by displacing MASP-2 from MBL, hence preventing cleavage of C4 and C2 {{cite journal | vauthors = Degn SE, Hansen AG, Steffensen R, Jacobsen C, Jensenius JC, Thiel S | title = MAp44, a human protein associated with pattern recognition molecules of the complement system and regulating the lectin pathway of complement activation | journal = Journal of Immunology | volume = 183 | issue = 11 | pages = 7371–8 | date = December 2009 | pmid = 19917686 | doi = 10.4049/jimmunol.0902388 | url = http://www.jimmunol.org/cgi/content/full/183/11/7371 | doi-access = free }}