Stress and polyamine metabolism in fungi

Abstract

Fungi, as well as the rest of living organisms must deal with environmental challenges such as stressful stimuli. Fungi are excellent models to study the general mechanisms of the response to stress, because of their simple, but conserved, signal-transduction and metabolic pathways that are often equivalent to those present in other eukaryotic systems. A factor that has been demonstrated to be involved in these responses is polyamine metabolism, essentially of the three most common polyamines: putrescine, spermidine and spermine. The gathered evidences on this subject suggest that polyamines are able to control cellular signal transduction, as well as to modulate protein-protein interactions. In the present review, we will address the recent advances on the study of fungal metabolism of polyamines, ranging from mutant characterization to potential mechanism of action during different kinds of stress in selected fungal models.

Keywords: fungi; metabolism; polyamine mutants; polyamines; stress response.

Figure 1

General pathway for the biosynthesis and catabolism of polyamines in fungi.

Figure 2

Comparative analysis of different stress conditions on the growth of wild type, and simple and double mutants of U. maydis affected in different steps of polyamine metabolism. After depletion of polyamine pools, cell suspensions were decimally diluted and inoculated on solid minimal medium containing 20 mM lysine and 0.1 mM spermidine. After 48 h of incubation at 28°C (except in C), photographs were taken. (A), control; (B), 1.5 M KCl added to the medium; (C), as (A), but incubated at 37°C; (D), 1 M NaCl added to the medium.