Regulatory mechanism of the expression of vimentin gene during the differentiation of leukemic cells.

为探讨波形蛋白基因在小鼠髓系白血病细胞(M1)分化过程中的调控机制，克隆了小鼠波形蛋白基因，并用氯霉素乙酰转移酶(CAT)分析了其5‘启动子区域的转录活性。对各种缺失突变体的分析表明，波形蛋白启动子近端的188个碱基片段足以在M1细胞中有效转录。这个188个碱基的序列在小鼠、仓鼠和人类的波形蛋白基因之间高度保守。对突变和嵌合波形蛋白启动子结构的详细分析确定，在转录起始点-89bp到-84bp之间的CCAAT box是一个重要的正调控元件。在CCAAT盒和TATA盒之间存在一个富含GC的元件，在Vimentin基因转录过程中起到很强的负调控作用。

To investigate the regulatory mechanisms of the vimentin gene during mouse myeloid leukemia cell (M1) differentiation, the mouse vimentin gene was cloned and the transcriptional activity of its 5' promoter region was analyzed by chloramphenicol acetyl transferase (CAT) assay. Analyzes of various deletion mutants revealed that a 188 bp fragment of the proximal vimentin promoter was sufficient for effective transcription in M1 cells. This 188 bp sequence is highly conserved between the mouse, hamster and human vimentin genes. Detailed analyzes of mutant and chimeric vimentin promoter constructs defined a CCAAT box at-89 bp to-84 bp from the transcriptional start site to be an essential positive regulatory element. A GC rich element between the CCAAT box and TATA box was found to act as a strong negative regulatory element in vimentin gene transcription.