MASP1 (protein)

MASP1 (Mannan-binding lectin serine protease 1) is a protein that in humans is encoded by the MASP1 gene. It is a component of the immune system, specifically the complement system, and plays a crucial role in the body's defense against pathogens.

Structure

MASP1 is a serine protease that is structurally similar to C1s and C1r proteins, which are part of the classical complement pathway. It consists of a CUB (C1r/C1s, Uegf, Bmp1) domain, an EGF (epidermal growth factor) domain, two CCP (complement control protein) domains, and a SP (serine protease) domain.

Function

MASP1 is involved in the lectin pathway of the complement system. It is capable of cleaving C4 and C2 complement proteins, leading to the formation of the C3 convertase, C4b2a. This is a crucial step in the activation of the complement system, which plays a key role in the immune response to infection.

Clinical significance

Mutations in the MASP1 gene have been associated with 3MC syndrome, a rare genetic disorder characterized by facial, umbilical, and ear abnormalities. Additionally, variations in the MASP1 gene may influence susceptibility to certain infectious diseases, such as malaria and meningococcal disease.

See also

• MASP2
• Complement system
• 3MC syndrome

References

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