Suzuki S, Aratani Y, Koyama H
Kihara Institute for Biological Research, Yokohama City University, Japan.
Biochem Biophys Res Commun. 1993 Dec 30;197(3):1194-202. doi: 10.1006/bbrc.1993.2603.
The effect of SV40 and MMTV promoters on intermolecular homologous recombination between neomycin (neo) genes carrying deletions proximal and distal to the promoters has been examined in rat XC cells. One deleted neo gene linked to either promoter and the other deleted one without any promoter were co-transfected to cells so that the number of resulting G418-resistant colonies reflected the frequency at which the promoter-linked neo allele had been corrected by homologous recombination. We found that when the the distal deletion was placed under the SV40 promoter, it was corrected over 20-fold more frequently than the proximal. In contrast, when the MMTV promoter replaced the SV40 promoter, the distal deletion was corrected only 2-fold frequently compared with the proximal, and this result did not alter by activating the promoter with a glucocorticoid hormone dexamethasone. These results suggest that the preferential gene correction event observed with the SV40 promoter is attributed not to the transcriptional activity but to some specific sequence of the promoter.
在大鼠XC细胞中，研究了SV40和MMTV启动子对携带启动子近端和远端缺失的新霉素（neo）基因之间分子间同源重组的影响。将一个与任一启动子相连的缺失neo基因和另一个没有任何启动子的缺失neo基因共转染到细胞中，这样产生的G418抗性菌落数量反映了启动子相连的neo等位基因通过同源重组被校正的频率。我们发现，当远端缺失置于SV40启动子下时，其校正频率比近端缺失高20倍以上。相反，当MMTV启动子取代SV40启动子后，远端缺失的校正频率仅比近端高2倍，并且用糖皮质激素地塞米松激活启动子后这一结果并未改变。这些结果表明，观察到的SV40启动子优先基因校正事件并非归因于转录活性，而是归因于启动子的某些特定序列。
