Spermidine localization

Polyamines, such as spermine, spermidine, putrescine, cadaverine, are natural substances widely distributed in vegetable, animal and bacterial cells. They enter in the composition of bacterial viruses. They have a wide range of effects, but they are difficult to localize within the cell and their physiological significance is not understood very well. In animal cells and sera there exists a diamineoxidase which converts spermine into highly cytotoxic compounds, and many effects seen in tissue cultures are attributed to these substances. 

Ishfaq M, Maeta K, Maeda S et al (2012) Acetylation regulates subcellular localization of eukaryotic translation initiation factor 5A (elF5A). FEBS Lett 586 3236-3241 Jakus J, Wolff EC, Park MH et al (1993) Features of the spermidine-binding site of deoxyhypusine synthase as derived from inhibition studies. Effective inhibition by bis- and mono-guanylated diamines and polyamines. J Biol Chem 268 13151-13159 JasiuUonis MG, Luchessi AD, Moteira AG et al (2007) Inhibition of eukaryotic translation initiation factor 5A (elF5A) hypusination imptiirs melanoma growth. Cell Biochem Fund 25 109-114... 

The main subcellular PA-binding sites are probably (I) RNA, both ribosomal and transfer, (2) DNA, both nuclear and oiganellar, (3) cell wall, and (4) membranes (Bachrach, 1970). It is well known that PAs, like Mg, bind to ribosomes and facilitate the association of ribosomal subunits (see reviews in Tabor and Tabor, 1976,1984). Polyamines can bind to specific sites on tRNA molecules (Pochon and Cohen, 1972 Sakai and Cohen, 1973). In plants, bound putrescine, spermidine, and spermine have been found in ribosomes (Cocucci and Bagni, 1968), as well as in complexes with rRNA and tRNA (Bagni et ai, 1973 Serafini-Fracassini et ai, 1984). On the other hand, numerous studies have shown the interaction and stabilization of DNA by PAs as well as their binding to this macromolecule (see reviews in Bachrach, 1970 Cohen and McCormick, 1979 Tabor and Tabor, 1984). In plants the information is scarce, but the occurrence of spermidine and spermine in chromatin isolated from com has been reported. Most of the spermine is probably chromatin bound in vivo (Hirasawa and Suzuki, 1985). However, the localization of PAs in the nucleus, in vivo, still remains somewhat uncertain (Tabor and Tabor, 1984). 

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