Sheiness D, Puckett L, Darnell J E
Proc Natl Acad Sci U S A. 1975 Mar;72(3):1077-81. doi: 10.1073/pnas.72.3.1077.
Whereas the original size of poly(A) in HeLa cells is about 200 nucleotides, at steady state most of the poly(A) in mRNA contains less than 50 nucleotides. An endonucleolytic attack on poly(A) is suggested as the most likely method to accumulate short pieces of poly(A). Both poly(A) shortening and mRNA turnover appear to be inhibited by emetine, a drug that stops translation. It is possible that a random endonucleolytic attack leads to scission of poly(A) to a size below which the mRNA is unstable.
虽然HeLa细胞中聚腺苷酸(poly(A))的原始长度约为200个核苷酸,但在稳态时,mRNA中的大多数聚腺苷酸所含核苷酸少于50个。对聚腺苷酸的内切核酸酶攻击被认为是积累短片段聚腺苷酸的最可能方式。聚腺苷酸缩短和mRNA周转似乎都受到放线菌酮的抑制,放线菌酮是一种能阻止翻译的药物。有可能随机的内切核酸酶攻击导致聚腺苷酸断裂成mRNA不稳定的长度以下。