Fibrinogen C Domain Containing Protein 1 (FIBCD1)

The predicted 461-amino acid protein has a 31-amino acid cytoplasmic tail at its N terminus, followed by a 23-amino acid transmembrane helix and a 408-amino acid ectodomain. The cytoplasmic tail has 2 potential phosphorylation sites. The ectodomain contains an acetyl group-binding fibrinogen -related domain (FRED) and sequences with homology to coiled-coil regions of myosins and angiopoietins. FIBCD1 shares significant homology with FCN2, M-ficolin (FCN1), and horseshoe crab tachylectin-5A (Tl5a). When expressed in HEK293 cells as a secreted protein, the FIBCD1 ectodomain had a molecular mass of 55 kD in the reduced state and 250 kD in the unreduced state by SDS-PAGE, and chemical cross-linking experiments showed that it formed disulfide-linked homotetramers.