Transfected cDNA directs expression of hemolytically active murine C4 in cultured mouse and monkey cells.
Transfected cDNA directs expression of hemolytically active murine C4 in cultured mouse and monkey cells.
复制标题
转染的 cDNA 指导具有溶血活性的鼠 C4 在培养的小鼠和猴细胞中的表达。
DOI：
10.1159/000463113
复制
发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Ogata,RT
中科院分区：
文献类型：
--
作者：
Picchi,MA;Bradt,BM;Cooper,NR;Ogata,RT
Previously cloned and sequenced full-length cDNAs for murine C4 and the closely related sex-limited protein (Sip) have been placed into an eucaryotic expression vector. Transfer of these DNA constructs transiently into monkey COS cells or stably into mouse L cells results in the expression and secretion of hemolytically active mouse C4 and mature Sip. We estimate from hemolytic activities that COS and L cells secrete 0.04 and 3%, respectively, of the C4 level found in mouse plasma. Sip expression is consistently only 10-20% that of C4 although the identical expression system is used for both. Our results show subtle but reproducible cell-type-specific differences in C4 maturation; they also indicate that surprisingly large shifts in electrophoretic mobility on SDS-polyacrylamide gels are induced by a small number of amino acid substitutions. The expression of C4 from cDNAs of known sequence provides a starting point for studies of structure/function relationships in C4 employing site-specific mutagenesis and gene transfer.
