FCN1
FCN1 (ficolin 1, also known as ficolin-1 or FCNM) is an extracellular lectin that acts as a pattern recognition receptor. It recognises carbohydrates on pathogen surfaces and initiates the lectin pathway of the complement system. Browse Assay Genie's current range of FCN1 research reagents below, or read on for the biology behind the target.
FCN1 is an extracellular lectin that works as a pattern recognition receptor. It specifically recognises and binds carbohydrates on the pathogen surface. This activates the serine protease MASP1 and starts the proteolytic cascade of the lectin complement pathway. That cascade leads to phagocytosis and breakdown of pathogens, and to signalling that strengthens the adaptive immune system. Ficolin-1 binds preferentially to 9-O-acetylated 2-6-linked sialic acid derivatives. It also binds various glycans that contain sialic acid in a 2-3 linkage.
The source annotation also notes that FCN1 may activate monocytes through a G protein-coupled receptor, FFAR2, which induces secretion of interleukin-8 (IL-8). The protein is found both secreted and on the cell surface. The FCN1 gene is predominantly expressed in peripheral blood leukocytes, and ficolin-1 has been postulated to act as a plasma protein with elastin-binding activity.
Ficolins are characterised by a leader peptide, a short N-terminal segment, a collagen-like region and a C-terminal fibrinogen-like domain. The collagen-like and fibrinogen-like domains also occur separately in other proteins, including complement C1q, the collectins and the tenascins. These proteins recognise different targets and are functionally distinct. HGNC places FCN1 in the fibrinogen C domain containing group, the complement system activation components and the ficolin family. Earlier names include ficolin (collagen/fibrinogen domain-containing) 1, and the previous symbol is FCNM. Mouse and rat both have an Fcn1 ortholog.
FCN1 initiates the lectin pathway by binding pathogen surface carbohydrates and activating MASP1, making it a focus for studies of complement activation.
As a pattern recognition receptor, ficolin-1 links glycan recognition on pathogens to phagocytosis and to signalling that strengthens adaptive immunity.
FCN1 may activate monocytes through the G protein-coupled receptor FFAR2, inducing IL-8 secretion, which is relevant to monocyte signalling research.
Ficolin-1 binds 9-O-acetylated 2-6-linked sialic acid derivatives and sialic acid glycans in a 2-3 linkage, supporting work on lectin specificity.
FCN1 is an extracellular lectin and pattern recognition receptor. It binds carbohydrates on pathogen surfaces and activates the MASP1 serine protease, which starts the lectin pathway of complement. This leads to phagocytosis and breakdown of pathogens. It may also activate monocytes through FFAR2, inducing IL-8 secretion.
The protein is called ficolin-1, and HGNC gives the full name as ficolin 1. The alias and previous symbol is FCNM. Earlier names were ficolin (collagen/fibrinogen domain-containing) 1. Check the datasheet of any product for its validated reactivity and the name it uses.
FCN1 belongs to the ficolin lectin family, alongside FCN2 and FCN3. Ficolins have a collagen-like region and a fibrinogen-like domain. These domains also occur in C1q, collectins and tenascins, but those proteins recognise different targets and are functionally distinct. Mouse and rat have an Fcn1 ortholog.
Other ficolin family members that take part in complement lectin pathway activation.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O00602; product specifications from Assay Genie datasheets.