FCN3

Ficolins are a group of proteins which consist of a collagen-like domain and a fibrinogen-like domain. In human serum, there are two types of ficolins, both of which have lectin activity. The protein encoded by this gene is a thermolabile beta-2-macroglycoprotein found in all human serum and is a member of the ficolin/opsonin p35 lectin family. The protein, which was initially identified based on its reactivity with sera from patients with systemic lupus erythematosus, has been shown to have a calcium-independent lectin activity. The protein can activate the complement pathway in association with MASPs and sMAP, thereby aiding in host defense through the activation of the lectin pathway. Alternative splicing occurs at this locus and two variants, each encoding a distinct isoform, have been identified. [provided by RefSeq, Jul 2008]

Full Name

Ficolin 3

Research Area

May function in innate immunity through activation of the lectin complement pathway. Calcium-dependent and GlcNAc-binding lectin. Has affinity with GalNAc, GlcNAc, D-fucose, as mono/oligosaccharide and lipopolysaccharides from S.typhimurium and S.minnesota.

Biological Process

Complement activation Source: UniProtKB
Complement activation, lectin pathway Source: UniProtKB
Defense response to virus Source: UniProtKB
Negative regulation of RNA biosynthetic process Source: UniProtKB
Negative regulation of viral entry into host cell Source: UniProtKB
Recognition of apoptotic cell Source: UniProtKB

Cellular Location

Secreted. Found in blood plasma, bronchus, alveolus and bile duct.

Involvement in disease

Ficolin 3 deficiency (FCN3D):
A disorder characterized by immunodeficiency, recurrent infections, brain abscesses and recurrent warts on the fingers. Affected individuals have normal levels of lymphocytes, normal T-cell responses, and normal antibodies, but a selective deficient antibody response to pneumococcal polysaccharide vaccine.

PTM

The N-terminus is blocked.