Development and analysis of secretory component disrupted mouse

分泌组分（SC）通常被称为聚合免疫球蛋白受体（pIgR），是SIgA的一个组分，在粘膜防御系统中起重要作用。SC位于粘膜部位上皮细胞的基底外侧膜上，是一种聚合免疫球蛋白的受体。因此，它通过上皮细胞将聚合免疫球蛋白和免疫复合物转运到分泌物中。SC是一个Mr为80 kDa的跨膜蛋白，cDNA上有1个外显子，由胞外区、跨膜区和细胞质尾部组成。本课题的目的是建立SC损伤小鼠，研究SC的功能，结果如下：1)利用小鼠pIgR cDNA筛选SC的基因组DNA，并对阳性克隆进行测序。2)获得5个阳性克隆。限制性内切酶图谱和Southern blotting结果显示，这些克隆有9.4 kb。测序结果显示，BamH I- ecor I片段长度为8404bp，外显子4、5、6、7、8、9、10分别为653 bp、352 bp、332 bp、192 bp、129 bp、131 bp和58 bp。内含子4、5、6、7、8、9、10分别为1237 bp、552 bp、891 bp、359 bp、3668 bp、1106 bp和1010 bp。EcoR I的第11外显子长度为2543 bp。

Secretory component (SC), often called polymeric immunoglobulin receptor (pIgR), is a component of SIgA which plays an important role in the mucosal defense system. SC which is localized on the basolateral membrane of the epithelial cells at the mucosal site is a receptor for polymeric immunoglobulins. Accordingly, it transports polymeric immunoglobulin and immune complex through epithelial cells into the secretion. SC is a transmembrane protein with an Mr of 80 kDa abd cDNA revealed 1 lexons composed of extracellular region, transmembrane region and cytoplasmic tail.The purpose of this project is to develop SC disrupted mouse to examine the function of SC.The results obtained were as follows;1) genomic DNA for SC was screened using a mouse pIgR cDNA and was determined by sequencing of positive clones.2) Five positive clones were obtained. The results of restriction enzyme map and Southern blotting revealed a 9.4 kb of these clones. Sequencing analysis indicated that the BamH I-EcoR I fragment was 8404bp, and exon 4, 5, 6, 7, 8, 9, 10 were 653 bp, 352 bp, 332 bp, 192 bp, 129 bp, 131 bp and 58 bp, respectively. Introns 4, 5, 6, 7, 8, 9, 10 were 1237 bp, 552 bp, 891 bp, 359 bp, 368 bp, 1106 bp and 1010 bp, respectively. The size of the exon 11 to EcoR I fragment was 2543 bp.