Cellular eukaryotic initiation factor 5A content as a mediator of polyamine effects on growth and apoptosis.
The polyamines are essential for eukaryotic cell growth. One of the most critical effects of polyamines on cell growth is the availability of spermidine for the post-translational modification of eIF-5A. Because hypusine-containing eIF-5A is necessary for cell proliferation, depletion of cellular polyamines suppresses growth by depleting cellular modified eIF-5A content. Excess putrescine accumulations in DH23A/b cells induces apoptosis and suppresses the formation of hypusine-containing eIF-5A. Treatment of DH23A/b cells with diaminoheptane also suppresses modified eIF-5A formation and induces apoptosis. These data suggest that suppression of modified eIF-5A formation may play a role in putrescine-induced apoptosis as well.
Tome
M E
ME
Department of Biochemistry, University of Arizona, Tucson 85724, USA.
Gerner
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EW
D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002455:Cell Division; D006801:Humans; D008239:Lysine / Q000031:analogs & derivatives / Q000502:physiology; D010448:Peptide Initiation Factors / Q000502:physiology*; D011700:Putrescine / Q000502:physiology*; D016601:RNA-Binding Proteins; D015398:Signal Transduction; D000097574:Eukaryotic Translation Initiation Factor 5A
D008239:Lysine; D010448:Peptide Initiation Factors; D011700:Putrescine; D016601:RNA-Binding Proteins; D000097574:Eukaryotic Translation Initiation Factor 5A; C100028:hypusine