Active transport of dimethialium in Saccharomyces cerevisiae

Dimethialium, a derivative of thiamine which has a methyl group in place of hydroxyethyl group at the t-position of the thiazole moiety, was found to be accumulated in nonproliferating cells of Saccharomyces cerevisiae by the same transport mechanism for thiamine. The results strongly support the supposition that thiamine as well as dimethialium can be transported and accumulated without obligatory phosphorylation in yeast cells, since dimethialium is not phosphorylated by yeast thiamine pyrophosphokinase.