Figure 6.
The number of lysyl residues modulates the toxicity of endogenously synthesized RTA. Tobacco protoplasts were cotransfected with a plasmid encoding phaseolin and either empty vector (pDHA) or a plasmid encoding wild-type or mutated RTA. After overnight recovery, protoplasts were pulsed for 1 h with radiolabeled amino acids, and proteins were immunoselected with anti-phaseolin antiserum. The intensity of the phaseolin band was quantified and plotted as a percentage of the intensity in samples cotransfected with the pDHA vector. Vertical bars indicate sd. A, Effect of wild-type RTA, RTA0K, and RTA6K expression on the synthesis of the phaseolin reporter. This represents an average of three experiments performed in triplicate. B, Effect of wild-type RTA and RTAW27V expression on the synthesis of the phaseolin reporter. This represents an average of two experiments performed in triplicate.