Irwin D, Kumar A, Malt R A
Cell. 1975 Feb;4(2):157-65. doi: 10.1016/0092-8674(75)90122-1.
As an initial step towards understanding the role of mRNP complexes in translational regulation during compensatory renal hypertrophy, characteristics of polysome-associated mRNP isolated by affinity chromatography were studied. Renal mRNP contained 15-30 percent of the counts after a 1 hr pulse with -3H-orotic acid; it sedimented mainly between 10S and 100S and had a buoyant density of 1.42-1.44 g/cm-3. RNA derived from the mRNP sedimented between 5S and 40S on sucrose density gradients, with the greatest radioactivity in the region of 15S. After labeling with -3H-adenine for 1 hr, up to 17 percent of the radioactivity present in the mRNP-associated RNA was resistant to digestion by pancreatic and T1 ribonucleases. The mRNP protein moiety contained six polypeptides with molecular weights 69,000, 75,000, 80,000, 100,000, 109,000, and 118,000 daltons, which were undetected in the material not binding to oligo(dT)-cellulose.
作为了解mRNP复合物在代偿性肾肥大期间翻译调控中作用的第一步，对通过亲和层析分离的多核糖体相关mRNP的特性进行了研究。在用-3H-乳清酸脉冲标记1小时后，肾mRNP含有15%-30%的放射性计数；它主要沉降在10S至100S之间，浮力密度为1.42-1.44 g/cm-3。从mRNP衍生的RNA在蔗糖密度梯度上沉降在5S至40S之间，在15S区域放射性最强。在用-3H-腺嘌呤标记1小时后，mRNP相关RNA中高达17%的放射性对胰核糖核酸酶和T1核糖核酸酶的消化具有抗性。mRNP蛋白部分包含六种分子量分别为69,000、75,000、80,000、100,000、109,000和118,000道尔顿的多肽，在不与寡聚（dT）-纤维素结合的物质中未检测到这些多肽。
