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Regulation of spermidine/spermine N 1 ‐acetyltransferase by intracellular polyamine pools
Author(s) -
Shappell N.W.,
Fogel-Petrovic M.F.,
Porter C.W.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)80103-2
Subject(s) - spermidine , spermine , polyamine , intracellular , biochemistry , acetyltransferase , biology , chemistry , enzyme , acetylation , gene
Through its role in polyamine acetylation and the back‐conversion pathway, spermidine/spermine N 1 ‐acetyltransferase (SSAT) has the potential to control intracellular polyamine pools by facilitating their catabolism and/or excretion. The possibility that the enzyme is subject to regulation by intracellular polyamine pools was investigated in MALME‐3 human melanoma cells. Increases in intracellular polyamine pools by treatment with 3 μM exogenous spermidine or spermine for 48 h caused SSAT activity to increase 111% and 226%, respectively, and SSAT‐specific mRNA to rise 19% and 66%, respectively. Decreases in polyamine pools by treatment with inhibitors of polyamine biosynthesis caused SSAT activity to decrease by 46% and mRNA to fall by 89%. Both SSAT activity and mRNA were more sensitive to changes in spermine than spermidine. The identification of a positive regulatory relationship between SSAT and intracellular polyamine pools further implicates this enzyme in a proposed model for polyamine pool homeostasis.