The alpha 1 (VIII) collagen gene is homologous to the alpha 1 (X) collagen gene and contains a large exon encoding the entire triple helical and carboxyl-terminal non-triple helical domains of the alpha 1 (VIII) polypeptide.
We recently cloned and sequenced alpha 1 (VIII) collagen cDNAs and demonstrated that type VIII collagen is a short-chain collagen that contains both triple helical and carboxyl-terminal non-triple helical domains similar to those of type X collagen (Yamaguchi, N., Benya, P., van der Rest, M., and Ninomiya, Y. (1989) J. Biol. Chem. 264, 16022-16029). We report here on the structural organization of the gene encoding the rabbit alpha 1 (VIII) collagen chain. The alpha 1 (VIII) gene contains four exons, whose sizes are 69, 120, 331, and 2278 base pairs. The first and second exons encode only 5'-untranslated sequences, whereas the third exon codes for a very short (3 nucleotides) stretch of 5'-untranslated sequence, the signal peptide, and almost the entire amino-terminal non-triple helical (NC2) domain (109 1/3 codons). Interestingly, the last exon encodes the rest of the translated region, including 7 2/3 codons of the NC2 domains, the complete triple helical domain (COL1, 454 amino acid residues), the entire carboxyl-terminal non-triple helical domain (NC1, 173 amino acid residues), and the 3'-untranslated region. This exon-intron structure is in stark contrast to the multi-exon structure of the fibrillar collagen (types I, II, III, V, and XI) genes, but it is remarkably similar to that of the type X collagen gene (LuValle, P., Ninomiya, Y., Rosenblum, N. D., and Olsen, B. R. (1988) J. Biol. Chem. 263, 18278-18385). The data suggest that the alpha 1 (VIII) and the alpha 1 (X) genes belong to the same subclass within the collagen family and that they arose from a common evolutionary precursor.
Yamaguchi
N
N
Department of Anatomy and Cellular Biology, Harvard Medical School, Boston, Massachusetts 02115-6092.
Mayne
R
R
Ninomiya
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003094:Collagen / Q000235:genetics* / Q000648:ultrastructure; D004247:DNA / Q000235:genetics; D005091:Exons; D005796:Genes; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D005810:Multigene Family; D011061:Poly A / Q000235:genetics; D012323:RNA Processing, Post-Transcriptional; D011817:Rabbits; D015183:Restriction Mapping
D011061:Poly A; D003094:Collagen; D004247:DNA