Regulation of spermidine/spermine N1-acetyltransferase by intracellular polyamine pools. Evidence for a functional role in polyamine homeostasis

FEBS Lett. 1993 Apr 26;321(2-3):179-83. doi: 10.1016/0014-5793(93)80103-2.


Through its role in polyamine acetylation and the back-conversion pathway, spermidine/spermine N1-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 microM 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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetyltransferases / genetics
  • Acetyltransferases / metabolism*
  • Blotting, Northern
  • Eflornithine / pharmacology
  • Gene Expression Regulation, Enzymologic / drug effects
  • Homeostasis
  • Humans
  • Melanoma
  • Models, Biological
  • Polyamines / metabolism*
  • Polyamines / pharmacology
  • Putrescine / metabolism
  • RNA, Messenger / drug effects
  • RNA, Messenger / metabolism
  • Spermidine / metabolism
  • Spermidine / pharmacology
  • Spermine / metabolism
  • Spermine / pharmacology
  • Tumor Cells, Cultured


  • Polyamines
  • RNA, Messenger
  • Spermine
  • Acetyltransferases
  • diamine N-acetyltransferase
  • Spermidine
  • Putrescine
  • Eflornithine