Practical Improvement of Signal Sequence Trap Method

点击翻译按钮获取中文摘要

Signal Sequence Trap (SST) method is an efficient cloning strategy for secretary proteins and type I transmembrane proteins and the method was innovated by our group. An independent research group of Genentech, a venture company in USA,reported a novel method by using secretion of yeast invertase out to the cells based on our report (Klein, RD,et al.Proc Natl Acad.Sci.U.S.A.1996,93 (14) : 7108). Comparing our original SST method and Genentech's novel method, the novel method turns out to be far more effective than our original method by a magnitude of 10,000. Then, we consider it reasonable to adapt the new method, instead of improving our original method. We start a large scale screening by using the novel yeast method.Based on the cDNA fragment obtained by SST method, full length cDNA's were cloned. Next, gene products of the cDNA's were obtained by expressing the cDNA's in Cos cells. We analyzed whether those proteins obtain some effects on the development and differentiation of blood cells. For this purpose, we utilized in vitro differentiation induction from mouse embryonic stem cells on OP9 stromal cells (OP9 system). This analysis is under way, however, no cDNA's containing significant effects on the development and differentiation of blood cells have been obtained.