Induced k efflux from cultured rose cells : effects of protein-synthesis inhibitors.

Inhibitors of translation, cycloheximide, emetine, and puromycin, and inhibitors of transcription, actinomycin D and cordycepin, stimulate a net efflux of K(+) from cultured cells of Rosa damascena. In the case of cycloheximide and emetine, this efflux bears many similarities to the efflux induced by ultraviolet radiation, including a lag period of 0.25 to 2.5 hours and a limited total loss of K(+). The efflux is transient, and continued incubation of cells with cycloheximide and emetine allows the cells to recover the K(+); after this, the cells no longer release K(+) in response to UV or to cycloheximide treatment. This suggests that the efflux process depends on continued protein synthesis. Other treatments such as cerulenin, low temperature (0 degrees C), and high temperature (40 degrees C) also inhibit the UV- and cycloheximide-induced K(+) efflux, suggesting that the induction of efflux may involve the synthesis of new plasma membrane.