Prenylaation

Prenylation is a type of post-translational modification where isoprenoid lipid groups, such as farnesyl or geranylgeranyl pyrophosphate, are attached to specific amino acid residues within a protein. This process, also known as isoprenylation, is crucial for the proper localization, function, and stability of many proteins. The prenyl group is typically attached to a cysteine residue located at or near the C-terminus of the target protein, often within a CaaX motif.

The enzymes responsible for prenylation are called prenyltransferases. These enzymes catalyze the formation of a thioether bond between the sulfur atom of the cysteine and the prenyl group. Farnesyltransferase (FTase) and geranylgeranyltransferase (GGTase) are the main types of prenyltransferases, differing in the length of the isoprenoid chain they transfer. This lipid modification can anchor proteins to cellular membranes, facilitating their interactions with other proteins and lipids.

Prenylation plays a significant role in various cellular processes, including signal transduction, protein trafficking, and cell cycle regulation. For example, prenylated proteins like Ras GTPases are critical components of signaling pathways that control cell growth and differentiation. Aberrant prenylation has been linked to various diseases, including cancer, and is therefore a target for therapeutic interventions.