Evidence for autoregulation of cystathionine gamma-synthase mRNA stabilityin Arabidopsis

Control of messenger RNA (mRNA) stability serves as an important mechanism, for regulating gene expression. Analysis of Arabidopsis mutants that overa ccumulate soluble methionine (Met) revealed that the gene for cystathionine gamma-synthase (CCS), the key enzyme in Met biosynthesis, is regulated at the Level of mRNA stability, Transfection experiments with wild-type and mu tant forms of the CCS gene suggest that an amino acid sequence encoded by t he first exon of CCS acts in cis to destabilize its own mRNA in a process t hat is activated by Met or one of its metabolites.