Replacing the nine C-terminal tail residues immediately preceding the CAAX motif does not significantly inhibit cleavage by ZMPSTE24.

Within the GFP-51mer, nine amino acids immediately upstream of the CAAX motif (underlined) were replaced with a nine amino acid long HA epitope and transiently transfected into HEK293A cells. A construct including an uncleavable (UC; L647R) version of the HA swap construct was generated and included as a marker for migration for cleavage inhibition, in addition to FTI treatment. The NF (non-farnesylated) as well as the uncleaved and the cleaved forms are indicated.