Identification of a phenotype-specific enhancer in the first intron of the rat collagen II gene.
Identification of a phenotype-specific enhancer in the first intron of the rat collagen II gene.
复制标题
大鼠 II 型胶原蛋白基因第一个内含子中表型特异性增强子的鉴定。
DOI：
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发表时间：
1987
影响因子：
11.1
通讯作者：
Y. Yamada
中科院分区：
文献类型：
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作者：
Walter E. Horton;T. Miyashita;Kimitoshi Kohno;John R. Hassell;Y. Yamada
通过将含有与氯霉素乙酰转移酶（CAT）基因偶联的该基因的潜在调控序列的质粒转染到各种细胞中来研究胶原II基因的调控。该基因的5'侧翼区在转染到鸡软骨细胞或成纤维细胞中时起弱启动子的作用。然而，在鸡软骨细胞和分化的肢芽细胞中包含第一个内含子的800个碱基片段会使CAT的转录增加约18倍，但在成纤维细胞、成肌细胞、肌肉源性成纤维细胞或畸胎瘤细胞中则不然。此外，该片段是活跃的，当放置在CAT基因的上游或下游，当存在于任一方向。通过使用进行软骨形成的肢芽间充质细胞的“微团”培养，检查这种增强剂与分化的关系。在该系统中，未分化的肢芽间充质细胞中没有观察到对增强子的反应。在分化成软骨细胞后，在这些细胞中观察到13倍的增强子效应。最后，全反式视黄酸，一种已知的致畸剂，显着抑制增强子活性的软骨细胞和分化的肢芽间充质细胞。这些结果表明，胶原蛋白II基因包含一个增强子元件中的第一个内含子，参与细胞特异性表达。
The regulation of the collagen II gene was investigated by transfecting plasmids containing potential regulatory sequences of this gene coupled to the gene for chloramphenicol acetyltransferase (CAT) into various cells. The 5' flanking region of this gene functioned as a weak promoter when transfected into chicken chondrocytes or fibroblasts. Inclusion of an 800-base fragment from the first intron, however, increased transcription of CAT approximately 18-fold in chicken chondrocytes and in differentiating limb bud cells but not in fibroblasts, myoblasts, muscle-derived fibroblasts, or teratocarcinoma cells. Furthermore, this fragment was active when placed either upstream or downstream of the CAT gene and when present in either orientation. The activity of this enhancer was examined in relation to differentiation by using "micromass" culture of limb bud mesenchyme cells undergoing chondrogenesis. In this system, no response to the enhancer was observed in undifferentiated limb bud mesenchyme cells. Following differentiation into chondrocytes, a 13-fold enhancer effect was observed in these cells. Finally, all-trans-retinoic acid, a known teratogen, dramatically suppressed enhancer activity in chondrocytes and differentiating limb bud mesenchyme cells. These results suggest that the collagen II gene contains an enhancer element in the first intron that is involved in cell-specific expression.