FGG Antibody – Rabbit Polyclonal

The protein encoded by this gene is the gamma component of fibrinogen, a blood-borne glycoprotein comprised of three pairs of nonidentical polypeptide chains. Following vascular injury, fibrinogen is cleaved by thrombin to form fibrin which is the most abundant component of blood clots. In addition, various cleavage products of fibrinogen and fibrin regulate cell adhesion and spreading, display vasoconstrictor and chemotactic activities, and are mitogens for several cell types. Mutations in this gene lead to several disorders, including dysfibrinogenemia, hypofibrinogenemia and thrombophilia. Alternative splicing results in two transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

Function: Fibrinogen has a double function: yielding monomers that polymerize into fibrin and acting as a cofactor in platelet aggregation.

Subunit structure: Heterohexamer; disulfide linked. Contains 2 sets of 3 non-identical chains (alpha, beta and gamma). The 2 heterotrimers are in head to head conformation with the N-termini in a small central domain

By similarity. Ref.19 Ref.22 Ref.23 Ref.24

Subcellular location: Secreted.

Domain: A long coiled coil structure formed by 3 polypeptide chains connects the central nodule to the C-terminal domains (distal nodules). The long C-terminal ends of the alpha chains fold back, contributing a fourth strand to the coiled coil structure.

Post-translational modification: Conversion of fibrinogen to fibrin is triggered by thrombin, which cleaves fibrinopeptides A and B from alpha and beta chains, and thus exposes the N-terminal polymerization sites responsible for the formation of the soft clot. The soft clot is converted into the hard clot by factor XIIIA which catalyzes the epsilon-(gamma-glutamyl)lysine cross-linking between gamma chains (stronger) and between alpha chains (weaker) of different monomers.Sulfation of C-terminal tyrosines increases affinity for thrombin.

Involvement in disease: Congenital afibrinogenemia (CAFBN) [MIM:202400]: Rare autosomal recessive disorder is characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen.Note: The disease is caused by mutations affecting the gene represented in this entry. Patients with congenital fibrinogen abnormalities can manifest different clinical pictures. Some cases are clinically silent, some show a tendency toward bleeding and some show a predisposition for thrombosis with or without bleeding.

Miscellaneous: The gamma-chain carries the main binding site for the platelet receptor.

Sequence similarities: Contains 1 fibrinogen C-terminal domain.