Mechanisms of protein prenylation and role in G protein function.

Introduction Covalent attachment of isoprenoid lipids is now recognized as an important modification of many proteins involved in cellular signalling [ 1,2]. This type of modification, termed prenylation, involves attachment of either the 15-carbon farnesyl or 20carbon geranylgeranyl isoprenoid to C-terminal cysteine residues of proteins. Known prenylated proteins include a number of GTP-binding regulatory proteins (G proteins); these proteins are responsible for controlling a wide spectrum of signal-transduction pathways [ 2,3]. Recent evidence indicates that prenylation imparts properties to these proteins that both promote their membrane interactions and influence their biological activities ~2~41.