Highly conserved upstream regions of the alpha 1-antitrypsin gene in two mouse species govern liver-specific expression by different mechanisms.
Highly conserved upstream regions of the alpha 1-antitrypsin gene in two mouse species govern liver-specific expression by different mechanisms.
复制标题
在两种小鼠中，α1-抗胰蛋白酶基因高度保守的上游区域通过不同的机制控制肝脏特异性表达。
DOI：
10.1128/mcb.10.2.760-769.1990
复制
发表时间：
1990
影响因子：
5.3
通讯作者：
Baumann,H
中科院分区：
文献类型：
--
作者：
Latimer,JJ;Berger,FG;Baumann,H
α1-抗胰蛋白酶（AT）是哺乳动物血清中主要的弹性蛋白酶抑制剂，主要在肝脏中产生。我们的特点是AT基因的结构和表达在小鼠speciesMus caroli，表达高水平的AT在肾脏以及肝脏。cDNA和基因组克隆分析表明，M. caroli与实验室小鼠（M.在整个编码区和5′-侧翼区，尽管这种广泛的序列保守性，这些物种之间的功能组织ofcis-acting调控元件的肝脏特异性表达是惊人的不同。瞬时转染实验表明M. Carolipromotor（即，相对于转录起始位点在-120和-2之间）的活性比M的类似区域高10倍。在一些实施方案中，本发明涉及一种在培养的肝细胞中驱动指示基因的表达的驯化菌素。M. caroliAT启动子的突变似乎是位置-46和-48处的两个碱基取代中的一个或两个的结果。M. domestiusis通过上游的存在，肝脏特异性增强子在-199和-520之间补偿; M中的类似区域。卡罗利不活跃。因此，在进化过程中，这两个物种AT基因5′侧翼区之间发生的适度7%序列差异产生了不同但同样有效的肝细胞特异性表达模式。
α1-Antitrypsin (AT), the major elastase inhibitor in mammalian serum, is produced primarily in the liver. We have characterized AT gene structure and expression in the mouse speciesMus caroli,which expresses high levels of AT in the kidneys as well as in the liver. Analysis of cDNA and genomic clones showed that the AT gene inM. caroliexhibits high sequence homology (>90%) to the gene in laboratory mice(M. domesticus)throughout the coding and 5′-flanking regions. Despite this extensive sequence conservation, the functional organization ofcis-acting regulatory elements governing liver-specific expression is strikingly different between these species. Transient-transfection assays showed that the proximal region of theM. carolipromoter (i.e., between -120 and -2 relative to the transcriptional start site) is 10-fold more active than the analogous region ofM. domesticusin driving the expression of an indicator gene in cultured liver cells. The increased activity of the proximal region of theM. caroliAT promoter appears to be the result of one or both of the two base substitutions at positions -46 and -48. The weak proximal promoter inM. domesticusis compensated for by the presence of upstream, liver-specific enhancers between -199 and -520; the analogous region inM. caroliis inactive. Thus, during the course of evolution, the modest 7% sequence divergence that has occurred between the 5′-flanking regions of the AT genes in these two species has generated distinct, yet equally effective, modes of hepatocyte-specific expression.