Pieper F R, Slobbe R L, Ramaekers F C, Cuypers H T, Bloemendal H
Department of Biochemistry, University of Nijmegen, The Netherlands.
EMBO J. 1987 Dec 1;6(12):3611-8. doi: 10.1002/j.1460-2075.1987.tb02692.x.
Varying lengths of the hamster desmin and vimentin promoter regions were fused to the bacterial chloramphenicol acetyl-transferase gene. These constructs were transfected into two different myogenic cell lines, T984 and C2C12. In both cell lines an increase in endogenous desmin expression takes place upon myogenesis. A region between -89 and +25 bp relative to the desmin transcription initiation site directs high-level tissue- and stage-specific expression upon in vitro myogenesis. At the myoblast stage, C2C12 cells appeared to express both desmin and vimentin, whereas in T984 myoblasts only vimentin expression was detected. Although vimentin is expressed during all stages of myogenesis, a strong decrease in vimentin expression occurs during differentiation of C2C12 cells. Vimentin--CAT constructs followed the endogenous expression pattern, showing that this down-regulation is mediated by 5' flanking sequences. Vimentin promoter activity is modulated by at least two separate regions, both in myogenic and in non-myogenic cell lines.
将不同长度的仓鼠结蛋白和波形蛋白启动子区域与细菌氯霉素乙酰转移酶基因融合。这些构建体被转染到两种不同的成肌细胞系T984和C2C12中。在这两种细胞系中，成肌过程中内源性结蛋白表达均增加。相对于结蛋白转录起始位点，-89至+25 bp之间的区域在体外成肌过程中指导高水平的组织和阶段特异性表达。在成肌细胞阶段，C2C12细胞似乎同时表达结蛋白和波形蛋白，而在T984成肌细胞中仅检测到波形蛋白表达。尽管波形蛋白在成肌的所有阶段均有表达，但在C2C12细胞分化过程中波形蛋白表达强烈下降。波形蛋白-CAT构建体遵循内源性表达模式，表明这种下调是由5'侧翼序列介导的。波形蛋白启动子活性受至少两个独立区域的调节，在成肌细胞系和非成肌细胞系中均如此。
