A new FACIT of the collagen family: COL21A1

Abstract
Interrogation of the Human Genome data for sequences related to the von Willebrand factor A‐domain module identified a previously unreported 4.1 kb full‐length cDNA that is predicted to encode a new member of the collagen superfamily of extracellular matrix proteins, collagen XXI. The domain organization of collagen XXI comprised an N‐terminal signal sequence, followed by single von Willebrand factor A‐domain and thrombospondin domains, and an interrupted collagen triple helix. The organization of these motifs predict that collagen XXI is a new member of the FACIT collagen sub‐family. Expression analysis indicated that COL21A1 mRNA is present in many tissues including heart, stomach, kidney, skeletal muscle and placenta, and radiation hybrid mapping localized the COL21A1 gene to 6p11‐12.