Fibrinogen C domain containing 1 (FIBCD1) is a protein that in humans is encoded by the ''FIBCD1'' gene localized on chromosome 9q34.1 in close proximity to the genes encoding L- and M-ficolin. FIBCD1 is thought to have a role in both host defence and gut homeostasis.

Function

FIBCD1 is a type II trans-membrane

endocytic Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. E ...

receptor that is expressed apically on enterocytes and on airway epithelial cells (Schlosser ''et al.'', 2009). It is thought to mediate the

endocytosis Endocytosis is a cellular process in which substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a vesicle containing the ingested material. E ...

of bound

ligands In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electro ...

which are released to the surroundings after degradation, with FIBCD1 being recycled to the

plasma membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (t ...

. The homology between FIBCD1 and members of the ficolins, which are extensively characterised pattern-recognition molecules that have roles in the immune response, indicate FIBCD1 may have a role in host defence. Two potential

phosphorylation In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, wh ...

sites in the

cytoplasmic In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...

part of FIBCD1 suggest that FIBCD1 also may be a signaling protein (Schlosser ''et al.'', 2009).

Structure

FIBCD1 forms homo-tetramers in the

, with each protein chain consisting of a short cytoplasmic tail, a trans-membrane helix, and an ectodomain containing a coiled-coil region, a polycationic region, and a C-terminal fibrinogen-like recognition domain, otherwise known as the FReD. (Shrive, ''et al.'', 2014)

Function

Structure

References

Further reading