The cloning and sequencing of alpha 1(VIII) collagen cDNAs demonstrate that type VIII collagen is a short chain collagen and contains triple-helical and carboxyl-terminal non-triple-helical domains similar to those of type X collagen.
We have isolated two overlapping cDNA clones covering 2425 base pairs encoding a short type VIII collagen chain synthesized by rabbit corneal endothelial cells. The cDNAs encode an open reading frame of 744 amino acid residues containing a triple-helical domain of 454 residues flanked by 117- and 173-residue amino and carboxyl non-triple-helical domains (called NC2 and NC1, respectively). Based on the identity between the DNA-derived amino acid sequence and the amino acid sequence of a type VIII collagen CNBr peptide obtained from rabbit corneal Descemet's membrane, we conclude that the cDNAs code for a type VIII collagen chain. We give this chain the designation alpha 1(VIII). The alpha 1(VIII) triple-helical domain contains eight imperfections in the Gly-X-Y repeated structure with Gly-X instead of a full triplet. The length of the triple-helical domain and number and relative locations of these imperfections are remarkably similar to those of chicken alpha 1(X) collagen. The amino acid sequence of the carboxyl three-quarters of the NC1 domain has high sequence similarity to that of alpha 1(X) collagen. These data suggest that the triple-helix coding portions and carboxyl three-quarters of the NC1 domains of the alpha 1(VIII) and alpha 1(X) genes have a common evolutionary origin.
Yamaguchi
N
N
Department of Anatomy and Cellular Biology, Harvard Medical School, Boston, Massachusetts 02115.
Benya
P D
PD
van der Rest
M
M
Ninomiya
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics*; D003488:Cyanogen Bromide; D004247:DNA / Q000235:genetics*; D004728:Endothelium, Corneal / Q000378:metabolism*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D014176:Protein Biosynthesis; D011487:Protein Conformation; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D011817:Rabbits; D012689:Sequence Homology, Nucleic Acid
D010446:Peptide Fragments; D012313:RNA; D003094:Collagen; D004247:DNA; D003488:Cyanogen Bromide