Rabek J P, Hsie D Y, Papaconstantinou J
Department of Human Biological Chemistry and Genetics, University of Texas Medical Branch, Galveston, TX 77550.
Biochim Biophys Acta. 1992 Apr 6;1130(3):317-25. doi: 10.1016/0167-4781(92)90445-6.
Expression of the alpha-fetoprotein (AFP) and albumin genes was examined in fetal mouse kidney by analysis of tissue mRNA pool sizes during development and transient expression assays in primary kidney tissue culture cells. AFP is expressed at a much lower level in kidney than in liver but transcription of the gene is activated early during development and repressed after birth with a time-course similar to liver. However, albumin mRNA was not detected in fetal or new born mouse kidney. Transient expression assays using AFP- and albumin-CAT (chloramphenicol acetyl transferase) vectors were employed to characterize cis-acting elements active in the regulation of AFP expression in kidney. Primary fetal liver and kidney cells in culture were used for these assays. The AFP promoter is active in kidney cells and the information necessary for tissue specific expression and developmental repression are contained within the first 1.0 kb of 5' flanking sequences of the AFP gene. In addition, the AFP upstream enhancer elements are inactive in primary kidney cells. The mouse albumin promoter is shown to be inactive in kidney cells. The results obtained using transient expression assays are consistent with the observed low level of AFP expression, developmental repression of AFP, and the absence of expression of albumin in the mouse kidney.
通过分析发育过程中组织mRNA库的大小以及对原代肾组织培养细胞进行瞬时表达检测，研究了小鼠胚胎肾中甲胎蛋白（AFP）和白蛋白基因的表达情况。AFP在肾中的表达水平远低于肝脏，但该基因的转录在发育早期被激活，出生后受到抑制，其时间进程与肝脏相似。然而，在胚胎或新生小鼠肾中未检测到白蛋白mRNA。使用AFP和白蛋白-氯霉素乙酰转移酶（CAT）载体进行瞬时表达检测，以鉴定在肾中调节AFP表达的顺式作用元件。这些检测使用了原代胚胎肝和肾细胞。AFP启动子在肾细胞中具有活性，组织特异性表达和发育抑制所需的信息包含在AFP基因5'侧翼序列的前1.0 kb内。此外，AFP上游增强子元件在原代肾细胞中无活性。小鼠白蛋白启动子在肾细胞中无活性。使用瞬时表达检测获得的结果与在小鼠肾中观察到的低水平AFP表达、AFP的发育抑制以及白蛋白表达缺失一致。
