Yeast genes overcoming growth arrest induced by 1, 10-phenantroline

In the yeast Saccharomyces cerevisiae various physiological effects can be observed upon the addition of 1,10-phenantroline to a culture. 1,10-phenantroline is an ion chelator with a very high affinity for Fe2+, Zn2+ and Cu2+. The stability constants of the respective complexes are 21, 17 and 18 (Callander and Barford, 1983). Because of this characteristic 1,10-phenantroline can be used to deprive microorganisms from these essential oligo-elements. In the presence of 100 to 250 μg/ml a total block mRNA synthesis is provoked within a period of maximum 10 min. This feature has often been exploited in the study of mRNA stability (Santiago et al., 1986). In the presence of 5 to 20 μg/ml the effects are less drastic. Veinot-Drebot et al. (1989) have noticed an inhibition of pre-rRNA synthesis with very little effect upon poly(A)+RNA synthesis. Concomitantly the culture arrests at “start” and the cells are accumulating in the unbudded state. During this process cells acquire thermotolerance (Barnes et al., 1990) apparently without the production of the full set of heat shock proteins.