Characterization of Genes for Polyamine Modulon
Polyamines are essential for normal cell growth and exist mainly as RNA-polyamine complexes in cells. Thus, effects of polyamines on protein synthesis have been studied. It was found that several kinds of protein synthesis, which are important for cell growth, were enhanced by polyamines at the level of translation. We proposed that a group of genes whose expression is enhanced by polyamines at the level of translation be referred to as a “polyamine modulon.” In Escherichia coli, most members of the polyamine modulon thus far identified were transcription factors. These transcription factors enhanced the synthesis of several kinds of mRNA and tRNA, and also rRNA. In this way, polyamines enhanced growth of E. coli. We also succeeded in identifying three kinds of “polyamine modulon” in mammalian cells. One of the mechanisms of polyamine stimulation at the molecular level was due to the stabilization of the bulged-out region of double-stranded RNA in mRNA. The procedures used to identify components of the polyamine modulon are described in this chapter.
Key wordsPolyamine modulon Protein synthesis Polyamine-RNA interaction Cell growth Cell viability Spermidine
We are grateful to Drs. K. Williams and A. J. Michael for critical reading of the manuscript prior to submission. This study was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science, and Technology, Japan.
- 1.Cohen SS (1998) A guide to polyamines. Oxford University Press, New York, pp 1–543Google Scholar
- 16.Sambrook J, Fritsch EF, Maniatis T (2001) Extraction, purification, and analysis of mRNA from eukaryotic cells, Chapter 7. In: Sambrook J, Russell DW (eds) Molecular cloning: A Laboratory Manual, 3rd edn. Cold Spring Harbor Laboratory, Cold Spring Harbor, New YorkGoogle Scholar
- 19.Nielsen PJ, Manchester KL, Towbin H, Gordon J, Thomas G (1982) The phosphorylation of ribosomal protein S6 in rat tissues following cycloheximide injection, in diabetes, and after denervation of diaphragm. A simple immunological determination of the extent of S6 phosphorylation on protein blots. J Biol Chem 257:12316–12321PubMedGoogle Scholar
- 23.Yoshida M, Meksuriyen D, Kashiwagi K, Kawai G, Igarashi K (1999) Polyamine stimulation of the synthesis of oligopeptide-binding protein (OppA). Involvement of a structural change of the Shine-Dalgarno sequence and the initiation codon AUG in OppA mRNA. J Biol Chem 274:22723–22728PubMedCrossRefGoogle Scholar
- 25.Terui Y, Higashi K, Taniguchi S, Shigemasa A, Nishimura K, Yamamoto K, Kashiwagi K, Ishihama A, Igarashi K (2007) Enhancement of the synthesis of RpoN, Cra and H-NS by polyamines at the level of translation in Escherichia coli cultured with glucose and glutamate. J Bacteriol 189:2359–2368PubMedCrossRefGoogle Scholar
- 33.Nishimura K, Okudaira H, Ochiai E, Higashi K, Kaneko M, Ishii I, Nishimura T, Dohmae N, Kashiwagi K, Igarashi K (2009) Identification of proteins whose synthesis is preferentially enhanced by polyamines at the level of translation in mammalian cells. Int J Biochem Cell Biol 41:2251–2261PubMedCrossRefGoogle Scholar