Polyisoprenylated G-proteins

Polyisoprenylated G-proteins are a broad class of signaling molecules, including the Ras superfamily of small GTPases and the gamma subunits of heterotrimeric G proteins, that require the covalent attachment of lipid isoprenoid groups for biological activity (Source: PubMed, PMID: 11084378). This post-translational modification, known as prenylation, involves the addition of a farnesyl or geranylgeranyl moiety to a C-terminal cysteine residue, which facilitates the anchoring of these proteins to cellular membranes where they orchestrate critical pathways for cell growth and survival (Source: UniProt, Lipid modification). Because oncogenic mutations in these proteins, particularly Ras isoforms, are central drivers of human malignancies, they have long been pursued as high-priority therapeutic targets (Source: NIH, National Cancer Institute). Current pharmacological strategies include farnesyltransferase inhibitors (FTIs) like Lonafarnib and Tipifarnib, as well as isoprenylcysteine analogs like SIG-1273, which aim to disrupt the membrane association and subsequent signaling of these proteins (Source: Nature Reviews Drug Discovery, doi:10.1038/nrd1039). However, therapeutic efficacy is often challenged by 'alternative prenylation,' a resistance mechanism where proteins like K-Ras bypass farnesyltransferase inhibition by undergoing geranylgeranylation (Source: Journal of Biological Chemistry, 272(24):15031-5).

Other names

Prenylated G-proteinsIsoprenylated GTPasesLipid-modified G-proteinsCAAX-box proteinsFarnesylated G-proteinsGeranylgeranylated G-proteins

Inhibition of post-translational lipid modification (prenylation) by targeting farnesyltransferase or geranylgeranyltransferase enzymes, or by using isoprenylcysteine analogs to compete for binding sites, thereby preventing membrane localization and downstream signaling.