Ryall J, Rachubinski R A, Nguyen M, Rozen R, Broglie K E, Shore G C
J Biol Chem. 1984 Jul 25;259(14):9172-6.
A cDNA clone complementary to mRNA encoding the precursor (Mr = 165,000) to the rat liver mitochondrial matrix enzyme carbamyl phosphate synthetase I (Mr = 160,000) was employed to compare relative amounts of the messenger in adult and fetal liver and in Morris hepatoma 5123D and 3924A cells. Northern blot analysis gave a size estimate for the messenger of 6,500-6,700 nucleotides. Carbamyl phosphate synthetase mRNA levels in 15-day-old fetal liver were less than 10% of adult levels; 5123D cells expressed the messenger at levels about 2-fold higher than normal adult liver, but the messenger was undetectable in 3924A cells. Albumin mRNA was also expressed in the former but not in the latter. Maintaining rats for 5 days on a diet containing 60% casein augmented the relative amount of carbamyl phosphate synthetase mRNA by about 2-fold, while a protein-free diet resulted in reduced levels of the mRNA (about 50% compared to animals on a normal diet). Finally, the pattern of hybridization of carbamyl phosphate synthetase cDNA to HindIII-digested genomic DNA showed no differences between normal liver and its corresponding hepatoma; however, a HindIII site polymorphism was observed between Buffalo and ACI rats.
利用一个与编码大鼠肝线粒体基质酶氨甲酰磷酸合成酶I（Mr = 160,000）的前体（Mr = 165,000）的mRNA互补的cDNA克隆，来比较成年和胎儿肝脏以及莫里斯肝癌5123D和3924A细胞中该信使RNA的相对含量。Northern印迹分析给出该信使RNA大小估计为6500 - 6700个核苷酸。15日龄胎儿肝脏中氨甲酰磷酸合成酶mRNA水平不到成年水平的10%；5123D细胞中该信使RNA的表达水平比正常成年肝脏高约2倍，但在3924A细胞中检测不到该信使RNA。白蛋白mRNA在前一种细胞中也有表达，而在后一种细胞中没有表达。给大鼠喂食含60%酪蛋白的饲料5天，氨甲酰磷酸合成酶mRNA的相对含量增加约2倍，而无蛋白饲料则导致该mRNA水平降低（与正常饮食的动物相比约为50%）。最后，氨甲酰磷酸合成酶cDNA与经HindIII消化的基因组DNA的杂交模式显示，正常肝脏与其相应肝癌之间没有差异；然而，在布法罗大鼠和ACI大鼠之间观察到一个HindIII位点多态性。
