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A new perspective on ornithine decarboxylase regulation: Prevention of polyamine toxicity is the overriding theme
Author(s) -
Morris David R.
Publication year - 1991
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240460203
Subject(s) - ornithine decarboxylase , ornithine decarboxylase antizyme , polyamine , perspective (graphical) , theme (computing) , putrescine , microbiology and biotechnology , chemistry , biochemistry , biology , enzyme , computer science , artificial intelligence , operating system
The polyamines are essential cellular components for growth. Control of a key regulated enzyme of polyamine biosynthesis, ornithine decarboxylase (ODC), as a function of growth, is an area of intense interest. A unique regulatory property of ODC is the short half‐life of the protein, which has been suggested to be an important factor in rapid activation of polyamine biosynthesis after cells are mitogenically stimulated. In this paper, it is argued that the biological significance of the short half‐life of ODC is unrelated to the rate of its induction to a new steady state by growth factors, which is in fact limited by the relatively long half‐life of the ODC mRNA. Instead, I suggest that the rapid turnover of ODC protein becomes of significance when cells cease growth and expeditious downregulation of the enzyme is important in preventing polyamine overproduction, which would result in cytotoxicity in the arrested cells. Although mitogenic activation of ODC expression has been studied extensively, there is very little known about the mechanisms controlling downregulation of polyamine biosynthesis during the arrest of animal cell growth. These considerations suggest that this would be a fertile area of future inquiry.