Protein farnesyltransferase in plants

Area of Science:

• Biochemistry
• Plant Molecular Biology

Background:

• Protein prenylation is a crucial post-translational modification in eukaryotes.
• The enzyme protein farnesyltransferase (FTase) catalyzes the transfer of a farnesyl group to specific cysteine residues in target proteins.
• FTase has been extensively studied in animals and yeast, but its presence and characteristics in plants are less understood.

Purpose of the Study:

• To investigate the presence and biochemical properties of protein farnesyltransferase in spinach.
• To determine the substrate specificity of plant FTase for different prenyl diphosphates.
• To confirm the occurrence of FTase activity across various plant species.

Main Methods:

• Enzyme assays were performed using spinach protein extracts and a nonapeptide acceptor.
• Various isoprenoid diphosphates, including all-trans isoprenoid diphosphates, cis-polyprenyl diphosphates, and dolichyl diphosphates, were used as substrates.
• The effect of divalent cations on enzyme activity was assessed.

Main Results:

• Protein farnesyltransferase activity was successfully demonstrated in spinach.
• The enzyme efficiently utilized all-trans isoprenoid diphosphates as substrates.
• Enzyme activity was significantly stimulated by the presence of divalent cations.
• FTase activity was confirmed in several other plant species examined.

Conclusions:

• Spinach possesses active protein farnesyltransferase with specific substrate preferences.
• Divalent cations play a role in modulating plant FTase activity.
• The findings confirm the widespread presence of FTase in the plant kingdom, suggesting conserved roles in protein prenylation.