真核生物中的翻译抑制：铁蛋白mRNA翻译抑制因子的部分纯化与特性分析

Translational repression in eukaryotes: partial purification and characterization of a repressor of ferritin mRNA translation.

作者信息

Walden W E, Daniels-McQueen S, Brown P H, Gaffield L, Russell D A, Bielser D, Bailey L C, Thach R E

机构信息

Department of Microbiology and Immunology, College of Medicine, University of Illinois, Chicago 60612.

出版信息

Proc Natl Acad Sci U S A. 1988 Dec;85(24):9503-7. doi: 10.1073/pnas.85.24.9503.

Mouse and rabbit ferritin mRNAs translate very poorly in rabbit reticulocyte lysates relative to most other mRNAs. This translational deficiency is not seen in wheat germ lysates, suggesting the presence of an inhibitor in reticulocyte lysate that is specific for ferritin mRNA. A specific repressor of ferritin mRNA translation has been partially purified from rabbit reticulocytes by differential ultracentrifugation, ammonium sulfate fractionation, and chromatography on phosphocellulose, DEAE-cellulose, and Sephacryl S-300. The elution profile from the latter suggests an aggregate molecular mass of approximately 180 kDa for the repressor. The inhibitory activity of this repressor against native ferritin mRNA can be relieved by adding in vitro transcripts of ferritin light-chain RNAs that contain the first 92 nucleotides of the 5' untranslated region. No other sequences appear to be necessary for this effect.

与大多数其他mRNA相比，小鼠和兔铁蛋白mRNA在兔网织红细胞裂解物中的翻译效率非常低。在小麦胚芽裂解物中未观察到这种翻译缺陷，这表明网织红细胞裂解物中存在一种对铁蛋白mRNA具有特异性的抑制剂。通过差速超速离心、硫酸铵分级分离以及在磷酸纤维素、二乙氨基乙基纤维素和Sephacryl S - 300上进行色谱分离，已从兔网织红细胞中部分纯化出铁蛋白mRNA翻译的特异性阻遏物。从后者得到的洗脱图谱表明该阻遏物的聚合分子量约为180 kDa。通过添加包含5'非翻译区前92个核苷酸的铁蛋白轻链RNA的体外转录本，可以解除这种阻遏物对天然铁蛋白mRNA的抑制活性。对于这种效应，似乎不需要其他序列。