Beaumont C, Jain S K, Bogard M, Nordmann Y, Drysdale J
J Biol Chem. 1987 Aug 5;262(22):10619-23.
We have investigated the regulation of ferritin synthesis during induction of Friend erythroleukemic cells by dimethyl sulfoxide. Northern blot analysis shows that mouse ferritin H and L mRNAs each contain approximately 1.1 kilobases. The levels of both mRNAs increase after addition of dimethyl sulfoxide in a biphasic manner. After a sharp rise in the first 6 h, the levels decline and then rise again over the next 90 h. These increases in mRNA levels reflect increased transcription of both mRNAs. Analysis of ferritin subunit synthesis surprisingly showed no corresponding increase in the rate of protein synthesis, suggesting that the additional mRNA was not in functional polysomes. These studies also indicated a novel processing of mouse ferritin H subunits. H subunits appear to be synthesized as a precursor of approximately 22,500. This form is not present in mature shells. Pulse-chase experiments indicated that the precursor is first processed to an intermediate form of 20,000 and then to the 18,000 component found in functional shells.
我们研究了二甲基亚砜诱导弗氏红白血病细胞过程中铁蛋白合成的调控。Northern印迹分析表明，小鼠铁蛋白H和L mRNA各自约含1.1千碱基。加入二甲基亚砜后，两种mRNA的水平呈双相增加。在前6小时急剧上升后，水平下降，然后在接下来的90小时内再次上升。mRNA水平的这些增加反映了两种mRNA转录的增加。对铁蛋白亚基合成的分析令人惊讶地表明，蛋白质合成速率没有相应增加，这表明额外的mRNA不在功能性多核糖体中。这些研究还表明了小鼠铁蛋白H亚基的一种新加工方式。H亚基似乎作为约22,500的前体合成。这种形式不存在于成熟的壳中。脉冲追踪实验表明，前体首先加工成20,000的中间形式，然后加工成功能性壳中发现的18,000组分。
