Analysis of the upstream regions governing expression of the chicken cardiac troponin T gene in embryonic cardiac and skeletal muscle cells.
Analysis of the upstream regions governing expression of the chicken cardiac troponin T gene in embryonic cardiac and skeletal muscle cells.
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DOI：
10.1083/jcb.107.2.573
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发表时间：
1988-08
影响因子：
7.8
通讯作者：
Ordahl, C P
中科院分区：
文献类型：
--
作者：
Mar, J H;Antin, P B;Cooper, T A;Ordahl, C P
编码心肌肌钙蛋白 T (cTNT) 的鸡基因在早期胚胎发育过程中在心肌和骨骼肌中表达，但在胎儿发育过程中在骨骼肌中受到特异性抑制。为了确定这两种相关细胞类型中控制单个基因转录的顺式作用序列是否相同，我们将与细菌氯霉素乙酰转移酶基因偶联的cTNT基因的启动子/上游片段转染到早期胚胎心肌细胞和骨骼肌细胞的原代培养物中。使用该测定系统，由cTNT启动子/上游区域指导的氯霉素乙酰转移酶活性在心肌或骨骼肌细胞中比在成纤维细胞中高两到三个数量级，表明负责细胞特异性表达的顺式元件驻留在cTNT基因的该区域中。缺失实验表明，胚胎心肌细胞中 cTNT 启动子活性需要位于 cTNT 转录起始位点上游 268 至 201 个核苷酸之间的 67 核苷酸 DNA 片段。该区域在胚胎骨骼肌细胞中不是必需的，因为仅包含 129 个上游核苷酸的 cTNT 启动子结构在这些细胞中具有转录活性。这些结果表明，早期胚胎心肌细胞和骨骼肌细胞中的 cTNT 表达需要不同的顺式作用序列。另一方面，位于更上游的非必需区域在两种细胞类型中以类似的方式影响这些最小区域的表达水平。因此，这些实验的数据表明，早期胚胎心肌细胞和骨骼肌细胞中 cTNT 启动子的转录受到顺式和反式中常见和不同的调节元件的控制。 [已发表的勘误表出现在 J Cell Biol 1988 年 10 月；107(4):1621]
The chicken gene encoding cardiac troponin T (cTNT) is expressed in both cardiac and skeletal muscle during early embryonic development, but is specifically repressed in skeletal muscle during fetal development. To determine if the cis-acting sequences governing transcription of a single gene in these two related cell types are the same, we have transfected promoter/upstream segments of the cTNT gene coupled to the bacterial chloramphenicol acetyltransferase gene into primary cultures of early embryonic cardiac and skeletal muscle cells. Using this assay system, chloramphenicol acetyltransferase activity directed by the cTNT promoter/upstream region was between two and three orders of magnitude higher in cardiac or skeletal muscle cells than in fibroblast cells, indicating that cis elements responsible for cell- specific expression reside in this region of the cTNT gene. Deletion experiments showed that a 67-nucleotide DNA segment residing between 268 and 201 nucleotides upstream of the cTNT transcription initiation site is required for cTNT promoter activity in embryonic cardiac cells. This region is not required in embryonic skeletal muscle cells because a cTNT promoter construction containing only 129 upstream nucleotides is transcriptionally active in these cells. These results demonstrate that different cis-acting sequences are required for cTNT expression in early embryonic cardiac and skeletal muscle cells. Nonessential regions residing farther upstream, on the other hand, affected the level of expression of these minimum regions in a similar manner in both cell types. The data from these experiments indicate, therefore, that transcription of the cTNT promoter in early embryonic cardiac and skeletal muscle cells is governed both by common and divergent regulatory elements in cis and in trans. [published erratum appears in J Cell Biol 1988 Oct;107(4):1621]