This gene encodes 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. The encoded protein 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. The encoded protein is also able to cleave fibrinogen and factor XIII and may 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. Alternate splicing results in multiple transcript variants.[provided by RefSeq, Apr 2010]
Forensic Context
A study in humans demonstrated that the MASP1 is significantly upregulated in trauma and sepsis patients compared to controls, showing excellent diagnostic ability with an AUC > 0.7 and correlating positively with disease severity metrics like APACHE-II scores and CRP levels [Xian et al. DOI:10.3389/fmed.2024.1320811].