Brown J A, Machida C A
Division of Neuroscience, Oregon Regional Primate Research Center, Beaverton 97006.
DNA Seq. 1994;4(5):319-24. doi: 10.3109/10425179409020858.
beta 3-adrenergic receptor mRNAs exhibit species-specific expression (human vs. rodent) in distinct anatomical regions and appear to be expressed abundantly within rodent adipose tissue, but only at low levels within corresponding human tissues. In order to determine the genetic basis of the differential expression of the rat and human beta 3-adrenergic receptor genes, we cloned and sequence the rat gene and compared the 5' flanking regions of the two genes to identify potential discriminators in transcriptional regulation. We have found that the rat and human beta 3-adrenergic receptor 5' flanking regions are only 67% similar, unlike the close sequence similarity observed between the coding blocks (> 90%) and also observed between species for the 5' flanking regions of other beta-adrenergic receptor subtype genes (> 90%). In addition, the rat beta 3-adrenergic receptor gene lacks the four potential cAMP responsive elements identified within the 5' flanking region of the human receptor gene. The striking divergence in regulatory sequences between the rat and human beta 3-adrenergic receptor genes may potentially explain the differences in species-specific expression and tissue localization of the rat and human receptor mRNAs.
β3 - 肾上腺素能受体mRNA在不同的解剖区域表现出物种特异性表达（人类与啮齿动物），并且似乎在啮齿动物脂肪组织中大量表达，但在相应的人类组织中仅低水平表达。为了确定大鼠和人类β3 - 肾上腺素能受体基因差异表达的遗传基础，我们克隆并测序了大鼠基因，并比较了这两个基因的5'侧翼区域，以识别转录调控中的潜在差异因素。我们发现大鼠和人类β3 - 肾上腺素能受体5'侧翼区域的相似性仅为67%，这与编码区之间观察到的高度序列相似性（>90%）不同，并且在其他β - 肾上腺素能受体亚型基因的5'侧翼区域的物种间相似性也很高（>90%）。此外，大鼠β3 - 肾上腺素能受体基因在人类受体基因5'侧翼区域内鉴定出的四个潜在cAMP反应元件。大鼠和人类β3 - 肾上腺素能受体基因调控序列的显著差异可能潜在地解释了大鼠和人类受体mRNA在物种特异性表达和组织定位上的差异。
