farnesylmodified

Farnesylmodified refers to a molecule that has undergone farnesylation. Farnesylation is a type of prenylation, a post-translational modification that attaches an isoprenoid lipid group to a protein. Specifically, farnesylation involves the addition of a farnesyl group, a 15-carbon isoprenoid derived from mevalonate. This modification typically occurs at a cysteine residue near the C-terminus of a protein, often within a specific sequence motif known as the CaaX box (where C is cysteine, a is an aliphatic amino acid, and X is any amino acid).

The attachment of the farnesyl group is catalyzed by enzymes called farnesyltransferases. This lipid modification plays a crucial role in protein function, primarily by increasing the hydrophobicity of the protein, which can facilitate its association with cellular membranes. Farnesylated proteins are often involved in signal transduction pathways and protein-protein interactions. For instance, small GTPases, such as Ras proteins, are frequently farnesylated, and this modification is essential for their localization to the plasma membrane and their subsequent biological activity. Disruptions in farnesylation can lead to various cellular defects and diseases, making farnesyltransferases potential targets for therapeutic intervention, particularly in cancer. The term "farnesylmodified" simply denotes that this prenylation process has occurred on a specific molecule.