ABSTRACT
Polyamines, in particular spermidine (Sp), and the tripeptide glutathione (GSH) are predominant metabolites in almost all organisms. The polycationic and aliphatic nature of polyamines favor their interaction with several macromolecules (i.e., nucleic acids, phospholipids, and proteins) and, hence, their involvement in a plethora of fundamental cellular events such as transcription, translation, regulation of enzyme activity, differentiation, and proliferation. In pathogens, the action of polyamines have been linked to microbial carcinogenesis, biofilm formation, escape from phagolysosomes, bacteriocin production, toxin activity, and protection from oxidative and acid stress (Shah and Swiatlo, 2008; Willert and Phillips, 2008). Apart from their regulatory or stabilizing role when forming complexes with different macromolecules, the polyamines also serve as substrates for the synthesis of different alkaloids in plants (Shoji and Hashimoto, 2015) and of deoxyhypusine in eukaryotic cells (Park, 2006). For instance, deoxyhypusine is incorporated to the eukaryotic translation initiation factor 5A (eIF5A), which transports newly transcribed mRNAs from the nucleus to the cytoplasm.
