Huang S C, Panagiotidis C A, Canellakis E S
Department of Pharmacology, Yale University School of Medicine, New Haven, CT 06510.
Proc Natl Acad Sci U S A. 1990 May;87(9):3464-8. doi: 10.1073/pnas.87.9.3464.
We find that the transcription of various ribosomal proteins can be differentially affected by polyamines and by changes in growth rates. Using strain MG1655 of Escherichia coli K-12 (F-, lambda-), we have determined the effects of polyamines and changes in growth rate on the transcription of several ribosomal genes and the polyamine-synthesizing enzymes ornithine decarboxylase (L-ornithine carboxy-lyase; EC 4.1.1.17) and arginine decarboxylase (L-arginine carboxylyase; EC 4.1.1.19). Ribosomal proteins S20 and L34 can be differentiated from the other ribosomal proteins studied; the transcription of S20 and L34 is especially sensitive to polyamines and less sensitive to changes in growth rates. In contrast, the transcription of S10, S15, S19, L2, L4, L20, L22, and L23 is insensitive to polyamines although it is particularly sensitive to changes in growth rates. Like S20 and L34, the transcription of ornithine decarboxylase and arginine decarboxylase is especially sensitive to polyamines. Polyamines specifically enhance the transcription of ribosomal proteins S20 and L34, and decrease that of ornithine decarboxylase and arginine decarboxylase. It is evident that polyamines can exert both positive and negative regulation of gene expression in E. coli that can be differentiated from the effects caused by changes in growth rates.
我们发现，多种核糖体蛋白的转录会受到多胺和生长速率变化的不同影响。利用大肠杆菌K - 12（F - ，λ - ）的MG1655菌株，我们确定了多胺和生长速率变化对几个核糖体基因以及多胺合成酶鸟氨酸脱羧酶（L - 鸟氨酸羧基裂解酶；EC 4.1.1.17）和精氨酸脱羧酶（L - 精氨酸羧基裂解酶；EC 4.1.1.19）转录的影响。核糖体蛋白S20和L34与所研究的其他核糖体蛋白不同；S20和L34的转录对多胺特别敏感，而对生长速率变化不太敏感。相比之下，S10、S15、S19、L2、L4、L20、L22和L23的转录对多胺不敏感，尽管它对生长速率变化特别敏感。与S20和L34一样，鸟氨酸脱羧酶和精氨酸脱羧酶的转录对多胺也特别敏感。多胺特异性地增强核糖体蛋白S20和L34的转录，并降低鸟氨酸脱羧酶和精氨酸脱羧酶的转录。显然，多胺在大肠杆菌中可对基因表达发挥正调控和负调控作用，这与生长速率变化所产生的影响不同。
