Abstract
Cystathionine γ-synthase (CGS) is the key enzyme for methionine biosynthesis. CGS mRNA stability is down regulated in response to S-adenosylmethionine (SAM). 11-13 amino acid region (MTO1 region) in the first exon 1 of the CGS gene is important for this regulation. As the exon 1 polypeptide acts in cis, it is likely that the regulation occurs during translation. This regulation has been successfully reconstituted in the in vitro translation system of wheat germ extract. In this study, GST tag-CGS exon 1 mRNA was translated in vitro and translation products were analyzed by Western blot using GST antibody. In the presence of SAM, accumulation of partial translation products was observed, which seemed to be translated up to around the MTO1 region. This result raises the possibility that translation is arrested around MTO1 region in the presence of SAM.
