LENS-SPECIFIC ENHANCER IN THE 3RD INTRON REGULATES EXPRESSION OF THE CHICKEN DELTA-1-CRYSTALLIN GENE
LENS-SPECIFIC ENHANCER IN THE 3RD INTRON REGULATES EXPRESSION OF THE CHICKEN DELTA-1-CRYSTALLIN GENE
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DOI：
10.1101/gad.1.8.818
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发表时间：
1987-10-01
影响因子：
10.5
通讯作者：
KONDOH, H
中科院分区：
文献类型：
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作者：
HAYASHI, S;GOTO, K;KONDOH, H
我们以前已经证明鸡δ 1-晶状体蛋白基因的组织特异性决定簇位于-100位的3'端（Hayashi等，1985）。由于该基因的启动子（delta 1-晶状体蛋白启动子）没有表现出任何组织特异性，我们通过将每个片段置于编码氯霉素乙酰转移酶（CAT）的异源转录单元的下游并通过转染原代培养物中的鸡组织来检查delta 1-晶状体蛋白基因的各个片段的组织特异性增强子活性。我们发现，一段跨越第三内含子具有很强的晶状体特异性增强子活性。这种“δ 1-晶状体蛋白增强子”在透镜细胞中激活δ 1-晶状体蛋白启动子20- 40倍的转录，并在不同程度上激活其他启动子。增强子区域的缺失分析表明，它覆盖了近1 kb，但没有明确的边界。对于其增强子效应，需要120 bp的核心区域和与某些相邻区域的关联。从基因中去除增强子完全废除了δ 1-晶状体蛋白的表达，并且在上游、内部或下游位置重新插入增强子恢复了表达。我们的结论是，δ 1-晶体蛋白增强子是一个必不可少的和主要的决定因素，晶体特异性的δ 1-晶体蛋白的表达。
We have previously shown that the tissue specificity determinant of the chicken delta 1-crystallin gene lies 3' of position -100 (Hayashi et al. 1985). Since the promoter of the gene (delta 1-crystallin promoter) did not show any tissue specificity, we examined various segments of the delta 1-crystallin gene for a tissue-specific enhancer activity by placing each segment downstream of a heterologous transcriptional unit coding for chloramphenicol acetyltransferase (CAT) and by transfecting chicken tissues in primary culture. We found that a segment spanning the third intron bears a strong lens-specific enhancer activity. This "delta 1-crystallin enhancer" activates transcription from the delta 1-crystallin promoter 20- to 40-fold in lens cells and to various degrees with other promoters. Deletion analysis of the enhancer region indicated that it covered nearly 1 kb but did not indicate clear-cut boundaries. For its enhancer effect the core region of 120 bp and associations with certain adjoining regions were required. Removal of the enhancer from the gene totally abolished delta 1-crystallin expression, and reinsertion of the enhancer in either upstream, internal, or downstream positions restored expression. We conclude that the delta 1-crystallin enhancer is an essential and major determinant for lens-specificity of delta 1-crystallin expression.