Figure 4.

Differential prenylation of substrates of CaaX protein prenyltransferases (a) under normal conditions and (b) in the presence of a FT inhibitor. Substrates are shown in the middle of each panel, with the two enzymes above and below. 'Vital-F' and 'Vital-GG' represent all the proteins for which farnesylation (Vital-F) or geranylgeranylation (Vital-GG) are essential; RhoB-GG represents geranylgeranylated RhoB and RhoB-F represents farnesylated RhoB. Thick arrow, normal prenylation activity; thin arrow, reduced prenylation activity through cross-specificity of the non-preferred enzyme; arrows with crosses, blocked prenylation activity during inhibition of FT; brackets, substituting prenylation activity by GGT1 during inhibition of FT.