Toribara N W, Roberton A M, Ho S B, Kuo W L, Gum E, Hicks J W, Gum J R, Byrd J C, Siddiki B, Kim Y S
Gastrointestinal Research Laboratory, Department of Veterans Affairs Medical Center, San Francisco, California 94121.
J Biol Chem. 1993 Mar 15;268(8):5879-85.
Gastric mucin is a large glycoprotein which is thought to play a major role in the protection of the gastrointestinal tract from acid, proteases, pathogenic microorganisms, and mechanical trauma. In this paper we describe the isolation by expression cloning and characterization of cDNAs which code for human gastric mucin. The cDNA sequence is characterized by a tandem repeat region whose individual repeat unit is 507 base pairs (169 amino acids) long. The translated sequence is rich in threonine, serine, and proline (31, 18, and 15%, respectively) and contains a relatively large amount of histidine (7.1%) and alanine (5.6%). RNA blot analysis shows a polydisperse pattern which is characteristic of mucins. Expression of this gene is highest in the stomach and gall bladder, with weaker expression in the terminal ileum and right colon. This expression pattern is different from other human mucins and indicates that this gene codes for a unique mucin. Fluorescence in situ hybridization techniques have localized this gene to chromosome 11p15.4-11p15.5. This is the third mucin to be localized to the 11p15 region and suggests a clustering of secretory mucin genes. We propose that this gene for human gastric mucin be called MUC6.
胃粘蛋白是一种大型糖蛋白，被认为在保护胃肠道免受胃酸、蛋白酶、致病微生物和机械损伤方面发挥着重要作用。在本文中，我们描述了通过表达克隆分离和鉴定编码人胃粘蛋白的cDNA。该cDNA序列的特征在于一个串联重复区域，其单个重复单元长507个碱基对（169个氨基酸）。翻译后的序列富含苏氨酸、丝氨酸和脯氨酸（分别为31%、18%和15%），并含有相对大量的组氨酸（7.1%）和丙氨酸（5.6%）。RNA印迹分析显示出一种多分散模式，这是粘蛋白的特征。该基因在胃和胆囊中的表达最高，在回肠末端和右结肠中的表达较弱。这种表达模式与其他人粘蛋白不同，表明该基因编码一种独特的粘蛋白。荧光原位杂交技术已将该基因定位到染色体11p15.4 - 11p15.5。这是第三个定位于11p15区域的粘蛋白，提示分泌性粘蛋白基因存在聚类现象。我们建议将这个人胃粘蛋白基因命名为MUC6。
