Ichimura S, Hamana K, Nenoi M
Department of Biology and Oncology, National Institute of Radiological Science, Chiba-shi, Japan.
Biochem Biophys Res Commun. 1998 Feb 13;243(2):518-21. doi: 10.1006/bbrc.1998.8129.
Polyamines are intrinsic polycations which play critical roles in cell proliferation. Ornithine decarbolylase (ODC) catalyzes the first step of polyamine biosynthesis converting ornithine to putrescine. In addition to polyamine degradation, spermidine/spermine acetyltransferase (SSAT) regulates interconversion pathway of spermine and spermidine to putrescine. We quantified the polyamines and mRNAs of ODC and SSAT in HeLa S3 cells at various stages during exponential and plateau phases of culturing. Unexpectedly, putrescine and SSAT mRNA levels increased remarkably at the plateau phase, in contrast to the decrease of ODC mRNA level. It will be suggested that the putrescine has a novel function linked to the arrest of cell growth in which the SSAT-mediated pathway producing putrescine takes part.
多胺是内源性聚阳离子，在细胞增殖中起关键作用。鸟氨酸脱羧酶（ODC）催化多胺生物合成的第一步，将鸟氨酸转化为腐胺。除了多胺降解外，亚精胺/精胺乙酰转移酶（SSAT）还调节精胺和亚精胺向腐胺的相互转化途径。我们对培养指数期和平稳期不同阶段的HeLa S3细胞中的多胺以及ODC和SSAT的mRNA进行了定量。出乎意料的是，与ODC mRNA水平下降相反，腐胺和SSAT mRNA水平在平稳期显著增加。这表明腐胺具有与细胞生长停滞相关的新功能，其中SSAT介导的产生腐胺的途径参与其中。
