Cloning and sequencing of pro-alpha 1 (XI) collagen cDNA demonstrates that type XI belongs to the fibrillar class of collagens and reveals that the expression of the gene is not restricted to cartilagenous tissue.

M Bernard,H Yoshioka,E Rodriguez,M Van Der Rest,T Kimura,Y Ninomiya,B R Olsen,F Ramirez

doi:10.1016/s0021-9258(18)37512-4

M Bernard, H Yoshioka + Show 6 more

Open Access

https://doi.org/10.1016/s0021-9258(18)37512-4

Copy DOI

Abstract

We have isolated several overlapping cDNA clones encoding alpha 1(XI) collagen chains from human and rat cDNA libraries. Together the human cDNAs code for 335 uninterrupted Gly-X-Y triplets, and a 264-amino acid C-propeptide, while the rat cDNAs cover the entire C-propeptide and about a third of the triple-helical domain. Comparison of the human and rodent nucleotide sequences showed a 95% sequence similarity. The identification of the clones as alpha 1(XI) cDNAs was based on the complete identity between the amino acid sequences of three human alpha 1(XI) cyanogen bromide peptides and the cDNA-derived sequence. Examination of and the cDNA-derived amino acid sequence showed a variety of structural features characteristic of fibrillar-forming collagens. In addition, nucleotide sequence analysis of a selected portion of the corresponding human gene revealed the characteristic 54-base pair exon motif. We conclude therefore that pro-alpha 1 (XI) collagen belongs to the group of fibrillar collagen genes. We also suggest that the expression of this gene is not restricted to cartilage, as previously thought, since the cDNA libraries from which the clones were isolated, originated from both cartilagenous and noncartilaginous tissues.

Highlights

From the $Departmentof Microbiology and Immunology, Morse Instituteof Molecular Genetics, State Universityof New York, Health Science Center at Brooklyn, Brooklyn, New York, 11203, the §Genetics Unit, Shriners Hospital, Montreal,Quebec, Canada H3GlA6, and the IlDepartment of Anatomy and Cellular Biology, Harvard Medical School, Boston, Massachusetts 02115
We have isolated several overlapping cDNA clones that the threechains are assembled into one parental tripleencoding al(X1) collagen chains from human and rat helical molecule, called Type XI collagen
We suggest that the expressioonf this gene is not pered by the limited epitope accessibility in the matrix, as restricted to cartilage, as previously thoughts,ince the observed for Type V collagen (Fitch et al, 1984;Ricard-Blum cDNA libraries from which the clones were isolated, et al, 1982)

Summary

RESULTS

Isolation and Characterization of Type V-related cDNA Clones-We have already documented the isolation of a distinct collagen-coding recombinant, OK4, from the GM 637 library (Weil et aZ., 1987). In order to obtain further 5' sequences, an appropriate subfragment of OK4 was utilized to screen 5 X lo4phage plaques of the Xgtll human placental tissue cDNA library. This analysis showed a level of amino acid divergence of only 6% in the C-propeptide and 5% in thetriple helical domain. These data suggested that the Type V-related gene product encoded by OK4 is expressed in at least four different tissues, of which two are cartilageneous.

TC Gn I"

Amino acids

DISCUSSION