Efficient farnesylation of an extended C-terminal C( x) 3X sequence motif expands the scope of the prenylated proteome

J Biol Chem. 2018 Feb 23;293(8):2770-2785. doi: 10.1074/jbc.M117.805770. Epub 2017 Dec 27.


Protein prenylation is a post-translational modification that has been most commonly associated with enabling protein trafficking to and interaction with cellular membranes. In this process, an isoprenoid group is attached to a cysteine near the C terminus of a substrate protein by protein farnesyltransferase (FTase) or protein geranylgeranyltransferase type I or II (GGTase-I and GGTase-II). FTase and GGTase-I have long been proposed to specifically recognize a four-amino acid CAAX C-terminal sequence within their substrates. Surprisingly, genetic screening reveals that yeast FTase can modify sequences longer than the canonical CAAX sequence, specifically C(x)3X sequences with four amino acids downstream of the cysteine. Biochemical and cell-based studies using both peptide and protein substrates reveal that mammalian FTase orthologs can also prenylate C(x)3X sequences. As the search to identify physiologically relevant C(x)3X proteins begins, this new prenylation motif nearly doubles the number of proteins within the yeast and human proteomes that can be explored as potential FTase substrates. This work expands our understanding of prenylation's impact within the proteome, establishes the biologically relevant reactivity possible with this new motif, and opens new frontiers in determining the impact of non-canonically prenylated proteins on cell function.

Keywords: Ras protein; enzyme; mass spectrometry (MS); post-translational modification; protein farnesylation; protein isoprenylation; yeast genetics.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alkyl and Aryl Transferases / antagonists & inhibitors
  • Alkyl and Aryl Transferases / chemistry
  • Alkyl and Aryl Transferases / genetics
  • Alkyl and Aryl Transferases / metabolism*
  • Amino Acid Motifs
  • Animals
  • Databases, Protein
  • Enzyme Inhibitors / pharmacology
  • Genes, Reporter
  • Green Fluorescent Proteins / chemistry
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • HEK293 Cells
  • Humans
  • Microscopy, Fluorescence
  • Models, Molecular*
  • Protein Prenylation* / drug effects
  • Protein Subunits / antagonists & inhibitors
  • Protein Subunits / chemistry
  • Protein Subunits / genetics
  • Protein Subunits / metabolism
  • Proteomics / methods
  • Rats
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Saccharomyces cerevisiae / enzymology
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / antagonists & inhibitors
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism
  • Substrate Specificity


  • Enzyme Inhibitors
  • Protein Subunits
  • Recombinant Fusion Proteins
  • Saccharomyces cerevisiae Proteins
  • enhanced green fluorescent protein
  • Green Fluorescent Proteins
  • Alkyl and Aryl Transferases
  • geranylgeranyltransferase type-I
  • p21(ras) farnesyl-protein transferase

Associated data

  • PDB/1TN8