FIG. 2.

Turnover of cys-3 mRNA and protein. The repression kinetics was examined at the transition stage when the methionine level in culture was increased from low (0.25 mM) to high (5 mM). 74A mycelia were harvested at different times after the increase of Met in the medium and were used to prepare total RNA and protein extract. The half-lives of cys-3 mRNA and protein were estimated by using the SigmaGel program. (A) RNA blot analysis of cys-3 transcript; (B) immunoblot analysis of CYS3 protein.