Synthesis of inducible enzymes in irradiated yeast: UV effects on regulation and activity per cell

The synthesis of two inducible enzymes in UV irradiated cells was determined during an 8 h postirradiation incubatin. In contrast to the reduction of synthesis shortly after irradiation the effect after a longer period of incubation depends on the radiation sensitivity of the strain. Since exposure inhibits division leading to different cell number in controls and irradiated samples the data are also analysed on a per cell basis. ta considerable increase of the activity per cell was observed. A maximum is reached at the end of the division delay.