Article of Significant Interest in This Issue

摘要

Mycophenolic acid (MPA), an inhibitor of guanidine nucleotide synthesis, is used as a drug for immunosuppression and anticancer chemotherapy. Jurkiewicz et al. ( ) explore the effects of MPA on transcription of tRNA genes in both yeast and mammalian cells, with a special focus on macrophages. They show that MPA rapidly inhibits tRNA synthesis by depleting GTP. Both tRNA levels and RNA polymerase III (Pol III) binding to tRNA genes decrease upon MPA treatment in mammalian cells. However, in yeast the decrease of tRNA levels is not accompanied by dissociation of polymerase from its templates. This may be a result of Pol III stalling.