Kimura T, Cheah K S, Chan S D, Lui V C, Mattei M G, van der Rest M, Ono K, Solomon E, Ninomiya Y, Olsen B R
Department of Orthopedic Surgery, Osaka University Medical School, Japan.
J Biol Chem. 1989 Aug 15;264(23):13910-6.
We have isolated three overlapping cDNA clones encoding the pro alpha 2(XI) collagen chain from a human chondrocyte cDNA library. Together, the cDNAs code for 257 uninterrupted Gly-X-Y triplets (almost 80% of the triple helical domain) and about 200 amino acid residues of the carboxyl telopeptide and carboxyl propeptide. The identification of the clones as pro alpha 2(XI) cDNAs was based on the complete identity between the amino acid sequences of three tryptic peptides derived from human alpha 2(XI) collagen and the cDNA-derived sequence. We have also sequenced six exons within a human genomic alpha 2(XI) cosmid clone. This sequence shows that although type XI collagen belongs to the fibril-forming class of collagens, there are substantial differences in exon sizes at the 3' end of the gene when comparing the alpha 2(XI) gene with those of human types I, II, and III collagens. Finally, pro alpha 2(XI) cDNA has been used as a probe to determine the location of the gene by in situ hybridization of chromosome spreads. The results demonstrate that the gene is located close to the region p212 on chromosome 6. Northern blot analysis shows that the gene is expressed in cartilage but not in adult liver, skin, and tendon.
我们从人软骨细胞cDNA文库中分离出了三个重叠的编码原α2（XI）胶原链的cDNA克隆。这些cDNA共同编码257个不间断的甘氨酸- X - Y三联体（几乎占三螺旋结构域的80%）以及羧基端肽和羧基前肽的约200个氨基酸残基。这些克隆被鉴定为原α2（XI）cDNA，依据是源自人α2（XI）胶原的三个胰蛋白酶肽段的氨基酸序列与cDNA推导序列完全一致。我们还对人基因组α2（XI）黏粒克隆中的六个外显子进行了测序。该序列表明，尽管XI型胶原属于形成纤维的胶原类别，但将α2（XI）基因与人类I型、II型和III型胶原的基因相比较时，在基因3'端的外显子大小存在显著差异。最后，原α2（XI）cDNA已被用作探针，通过染色体铺展原位杂交来确定该基因的位置。结果表明该基因位于6号染色体上靠近p212的区域。Northern印迹分析显示该基因在软骨中表达，但在成年肝脏、皮肤和肌腱中不表达。
