REGULATION OF MUCIN GLYCOPROTEIN BIOSYNTHESIS

上皮细胞表面有一层黏弹性的保护层 称为粘液。 这一层是第一道防线 对下层组织的机械、微生物或化学损伤。 具有特殊功能意义的是高度糖基化的， 粘蛋白糖蛋白类。 这些分子负责 粘液涂层的独特流变特性。 许多 口腔干燥症的特征性症状，包括粘膜 溃疡，斑块介导疾病的发生率增加， 非典型口腔感染与定量的 唾液粘蛋白的缺乏或质的变化。 我们的方法来 这个问题一直是研究正常粘蛋白的调节， 糖蛋白生物合成 通过这种方式，我们希望了解 可能是特定形式唾液分泌的机制 功能障碍 我们的主要工作是：（1）构建并鉴定编码 大鼠下颌下腺粘蛋白的蛋白质核心 糖蛋白（MG），（2）确定编码MG的mRNA水平， 脱辅基粘蛋白和富含谷氨酰胺/谷氨酸的蛋白质（GRP）， 这是在老鼠体内发现的另一类丰富的蛋白质 下颌下腺，（3）确定生物合成途径， MG和GRP，（4）继续澄清结构 和编码GRP的基因的组织。

Epithelial surfaces are protected by a slimy, visco-elastic coat termed mucus. This layer is the first line of defense against mechanical, microbial or chemical insult to the underlying tissues. Of particular functional significance are the highly glycosylated, mucin-glycoproteins. These molecules are responsible for the unique rheological properties of the mucus coat. Many of the symptoms which characterize xerostomia including mucosal ulceration, increased incidences of plaque mediated disease and atypical oral infections have been linked to either a quantitative lack of or qualitative change in salivary mucin. Our approach to this problem has been to study the regulation of normal mucin- glycoprotein biosynthesis. In this way we hope to gain insight into the mechanisms which may underlie specific forms of salivary dysfunction. We propose to: (1) construct and characterize cDNAs which code for the protein core of rat submandibular gland mucin- glycoprotein (MG), (2) determine levels of mRNA coding for the apo-mucin and the glutamine/glutamic acid rich proteins (GRP), which are another class of abundant proteins found in the rat submandibular gland, (3) define the biosynthetic pathway for both the MG and GRP and, (4) continue clarification of the structure and organization of genes which code for the GRP.