Kelly S J, Loria J, Gyves M T, Ilan J
Mol Cell Endocrinol. 1983 Feb;29(2):181-95. doi: 10.1016/0303-7207(83)90212-5.
Poly(A+)-containing mRNA from human term placenta was used to direct protein synthesis in a nuclease-treated rabbit reticulocyte lysate, which is dependent on mRNA and tRNA for maximal activity. The major protein product was human pre-placental lactogen (hPL). Addition of tRNA from rabbit liver, rabbit reticulocyte, human first trimester and term placenta, human liver and yeast resulted in 2-5-fold stimulation of [35S]methionine incorporation into total protein. Although all mammalian tRNA increased hPL synthesis, the relative synthesis as compared to endogenous globin was markedly different and most efficient with tRNA from term placenta. Addition of yeast tRNA increased total incorporation 3-fold but decreased incorporation of [35S]methionine into pre-hPL. These results suggest that the population of isoacceptor tRNAs may influence the expression of hPL in term placenta. Results are discussed by showing codon bias and usage of mRNA coding for hPL, alpha- and beta-hCG, rabbit globin and yeast alcohol dehydrogenase I.
来自人类足月胎盘的含多聚腺苷酸（Poly(A+)）的信使核糖核酸（mRNA）被用于在经核酸酶处理的兔网织红细胞裂解物中指导蛋白质合成，该裂解物的最大活性依赖于mRNA和转运核糖核酸（tRNA）。主要的蛋白质产物是人胎盘前催乳素（hPL）。添加来自兔肝脏、兔网织红细胞、人类孕早期和足月胎盘、人类肝脏及酵母的tRNA，可使[35S]甲硫氨酸掺入总蛋白的量增加2至5倍。尽管所有哺乳动物的tRNA都能增加hPL的合成，但与内源性珠蛋白相比，相对合成情况明显不同，且来自足月胎盘的tRNA最为有效。添加酵母tRNA使总掺入量增加了3倍，但减少了[35S]甲硫氨酸掺入前体hPL的量。这些结果表明，同功tRNA群体可能会影响足月胎盘中hPL的表达。通过展示编码hPL、α和β人绒毛膜促性腺激素（hCG）、兔珠蛋白及酵母乙醇脱氢酶I的mRNA的密码子偏好性和使用情况对结果进行了讨论。
