Berger S L, Birkenmeier C S
Biochim Biophys Acta. 1979 Mar 28;562(1):80-91. doi: 10.1016/0005-2787(79)90128-x.
The kinetics of degradation of newly synthesized, cytoplasmic polyadenylated RNA have been examined in normal human lymphocytes stimulated to grow with phytohemagglutinin. A single class of poly(A)-bearing RNA was identified with a half-life of approximately 50 h. In the presence of actinomycin D, the half-life was 5 to 6 h, and virtually no decay of pulse-labeled material was detectable after 6 h of chase incubation with cordycepin. These findings contrast sharply with data obtained from other growing human cells used as controls: polyadenylated mRNA in MOLT-4 cells, a cultured line of T lymphocytes, had a half-life of 2 h in the presence of actinomycin D. The stability of poly(A)-containing RNA in stimulated lymphocytes from normal donors is therefore not simply a manifestation of cell proliferation. In normal resting lymphocytes, Berger and Copper [(1975) Proc. Natl. Acad. Sci. U.S. 72, 3873--3877] reported the existence of 2 classes of polyadenylated mRNA with half-lives of under an hour and greater than 20 h, respectively. Since short-lived poly(A)-bearing mRNA is absent from mitogen-stimulated lymphocytes, the data suggest that stabilization of previously labile poly(A)-bearing RNA is one of many carefully regulated processes accompanying growth induction in normal lymphoid cells.
在经植物血凝素刺激而生长的正常人淋巴细胞中，对新合成的细胞质多聚腺苷酸化RNA的降解动力学进行了研究。鉴定出一类单一的含聚腺苷酸（poly(A)）的RNA，其半衰期约为50小时。在放线菌素D存在的情况下，半衰期为5至6小时，在用虫草素进行6小时的追踪孵育后，几乎检测不到脉冲标记物质的衰减。这些发现与用作对照的其他正在生长的人类细胞所获得的数据形成鲜明对比：在放线菌素D存在的情况下，MOLT-4细胞（一种T淋巴细胞培养系）中的多聚腺苷酸化mRNA半衰期为2小时。因此，正常供体的受刺激淋巴细胞中含聚腺苷酸（poly(A)）的RNA的稳定性并非仅仅是细胞增殖的表现。在正常静止淋巴细胞中，伯杰和库珀[（1975年）美国国家科学院院刊72，3873 - 3877]报告存在两类多聚腺苷酸化mRNA，其半衰期分别在1小时以内和超过20小时。由于有丝分裂原刺激的淋巴细胞中不存在短寿命的含聚腺苷酸（poly(A)）的mRNA，这些数据表明，先前不稳定的含聚腺苷酸（poly(A)）的RNA的稳定化是正常淋巴细胞生长诱导过程中许多受到精细调控的过程之一。
