Mikol D D, Alexakos M J, Bayley C A, Lemons R S, Le Beau M M, Stefansson K
Department of Neurology, University of Chicago, Illinois 60637.
J Cell Biol. 1990 Dec;111(6 Pt 1):2673-9. doi: 10.1083/jcb.111.6.2673.
Utilizing a cDNA clone encoding the oligodendrocyte-myelin glycoprotein (OMgp) to screen a human genomic DNA library, we have obtained a clone that contains the OMgp gene. The genomic clone was restriction mapped and the OMgp gene and its 5' and 3' flanking regions were sequenced. A single intron is found in the 5' untranslated region of the gene, while the coding region is uninterrupted by an intron. This placement of a single intron in the OMgp gene is identical to that of the gene for the alpha-chain of platelet glycoprotein Ib, which, along with OMgp, belongs to a family of proteins sharing two distinct structural domains: an NH2-terminal cysteine-rich domain and an adjacent domain of tandem leucine-rich repeats. Hence, it is possible that this family of proteins is not only related in terms of primary structure, but also through similar gene structure. Sequence comparison of the 5' and 3' flanking regions did not reveal striking similarities to other DNA sequences, and no obvious promoter elements were noted. By hybridization of the genomic clone to metaphase cells, we have localized the human OMgp gene to chromosome 17 bands q11-12, a region to which the neurofibromatosis type 1 gene has been previously mapped.
利用一个编码少突胶质细胞髓磷脂糖蛋白（OMgp）的cDNA克隆筛选人基因组DNA文库，我们获得了一个包含OMgp基因的克隆。对该基因组克隆进行了限制性图谱分析，并对OMgp基因及其5'和3'侧翼区域进行了测序。在该基因的5'非翻译区发现了一个内含子，而编码区没有被内含子打断。OMgp基因中单个内含子的这种位置与血小板糖蛋白Ibα链基因的位置相同，血小板糖蛋白Ibα链与OMgp一起属于一类共享两个不同结构域的蛋白质家族：一个NH2末端富含半胱氨酸的结构域和一个相邻的串联富含亮氨酸重复序列的结构域。因此，这个蛋白质家族不仅可能在一级结构方面相关，而且可能通过相似的基因结构相关。5'和3'侧翼区域的序列比较未发现与其他DNA序列有显著相似性，也未发现明显的启动子元件。通过将基因组克隆与中期细胞杂交，我们已将人OMgp基因定位到17号染色体q11-12带，先前已将1型神经纤维瘤病基因定位到该区域。
