Conservation of polyamine regulation by translational frameshifting from yeast to mammals

Regulation of ornithine decarboxylase in vertebrates involves a negative fe edback mechanism requiring the protein antizyme. Here we show that a simila r mechanism exists in the fission yeast Schizosaccharomyces pombe. The expr ession of mammalian antizyme genes requires a specific +1 translational fra meshift. The efficiency of the frameshift event reflects cellular polyamine levels creating the autoregulatory feedback loop. As shown here, the yeast antizyme gene and several newly identified antizyme genes from different n ematodes also require a ribosomal frameshift event for their expression. Tw elve nucleotides around the frameshift site are identical between S.pombe a nd the mammalian counterparts. The core element for this frameshifting is l ikely to have been present in the last common ancestor of yeast, nematodes and mammals.