Figure 2.

Farnesylcysteine and geranylgeranylcysteine α-carboxyl methyltransferase assays on isolated membranes from cultured tobacco BY-2 cells. Assays were performed essentially as described by Hrycyna and Clarke (1990). Production of base-labile radioactivity was measured as a function of time in the presence of tobacco membranes, S-adenosyl-l-[³H-methyl]Met, and 200 μm AFC, AGGC, or AGC. The background in the absence of exogenous methyl acceptor was identical to that detected in the presence of 200 μm AGC (data not shown).