人补体膜辅助调节蛋白(MCP)基因的克隆和序列分析

Cloning and Sequencing of Human Complement Membrane Cofactor Protein

应用 PCR方法 ,从成人肝 c DNA文库中扩增编码人补体膜辅助调节蛋白 (MCP)分子的 c DNA片段。该片段经双酶切后克隆于 p UC19载体中 ,并测定其序列。序列分析表明 ,该 c DNA长 112 2 bp,编码 36 9氨基酸残基组成的蛋白 ,属于 STC+CYT2亚型。

Human membrane cofactor protein(MCP,CD46) is a cell surface glycoprotein acting as a cofactor for the factor Ⅰ-mediated inactivation of C3b and C4b.The purpose of this study is to obtain the cDNA sequence encoding human MCP for further study.cDNA fragment was amplified with PCR using adult liver cDNA library as template.The fragment was cloned into pUC19 plasmid,and further sequenced using Dye Terminator Cycle Sequencing Kit with AmpliTaq DNA Polymerase by ABI PRISMTM 377 DNA Sequencer.The cDNA fragment has 1 110 bp with open reading region,which encoded the signal peptide,four extracellular short consensus repeat domains(SCRs),a Ser/Thr(STC)-rich region,a transmembrane region and a cytoplasmic tail(CYT2).Its sequence was identical to the published sequence encoding ST C CYT2 isoform of human MCP.