Farnesylaatio

Farnesylaatio is a type of protein modification known as prenylation. It involves the covalent attachment of a farnesyl group, a 15-carbon isoprenoid lipid, to a cysteine residue near the C-terminus of a target protein. This process is catalyzed by an enzyme called farnesyltransferase. Farnesyl groups are derived from farnesyl pyrophosphate (FPP), a key intermediate in the mevalonate pathway.

The addition of a farnesyl group significantly alters the physical and chemical properties of the protein. The lipid tail makes the protein more hydrophobic, promoting its association with cellular membranes, particularly the plasma membrane. This membrane localization is crucial for the function of many farnesylated proteins, as it brings them into proximity with their signaling partners.

Farnesylaatio plays a vital role in the function of numerous proteins involved in cellular signaling, growth, and differentiation. Notable examples include members of the Ras superfamily of small GTPases, which are critical regulators of cell proliferation and survival. Improper farnesylaatio can lead to aberrant signaling and has been implicated in the development of various diseases, including cancer. Consequently, farnesyltransferase inhibitors have been explored as potential therapeutic agents for cancer treatment. The process is a dynamic one, with farnesylated proteins often undergoing subsequent modifications like proteolytic cleavage and methylation, which further refine their localization and activity.