Johnson J P, Rothbächer U, Sers C
Institute for Immunology, Munich, Germany.
Melanoma Res. 1993 Oct;3(5):337-40. doi: 10.1097/00008390-199310000-00006.
The cell surface glycoprotein MUC18 was originally identified as a progression associated antigen in melanoma. MUC18 is expressed most strongly on metastatic lesions and advanced primary tumours and is only rarely detected in benign lesions. cDNA cloning revealed MUC18 to be a novel member of the immunoglobulin superfamily with sequence similarity to a number of cell adhesion molecules. Cloning of both the human and mouse MUC18 genes indicate that their predicted protein structures are very similar with an overall amino acid identity of 75%. Like its human counterpart, murine MUC18 is also expressed by transformed melanocytes. Analysis of the promoter region of the human gene has provided evidence for regulatory elements found in smooth muscle specific genes and in both human and mouse: this is the normal site of MUC18 expression. The presence of putative binding sites for the transcriptional factors AP-1, AP-2 and CREB, suggest that MUC18 gene expression can also be modulated by external factors.
细胞表面糖蛋白MUC18最初被鉴定为黑色素瘤中的一种进展相关抗原。MUC18在转移性病变和晚期原发性肿瘤中表达最强，在良性病变中很少检测到。cDNA克隆显示MUC18是免疫球蛋白超家族的一个新成员，与许多细胞粘附分子具有序列相似性。人类和小鼠MUC18基因的克隆表明，它们预测的蛋白质结构非常相似，总体氨基酸同一性为75%。与人类对应物一样，小鼠MUC18也由转化的黑素细胞表达。对人类基因启动子区域的分析为在平滑肌特异性基因以及人类和小鼠中发现的调控元件提供了证据：这是MUC18表达的正常位点。转录因子AP-1、AP-2和CREB推定结合位点的存在表明，MUC18基因表达也可受外部因素调节。
