Hydrophilic anilinogeranyl diphosphate prenyl analogues are Ras function inhibitors

Biochemistry. 2006 Dec 26;45(51):15862-72. doi: 10.1021/bi061704+. Epub 2006 Dec 6.

Abstract

Sequential processing of H-Ras by protein farnesyl transferase (FTase), Ras converting enzyme (Rce1), and protein-S-isoprenylcysteine O-methyltransferase (Icmt) to give H-Ras C-terminal farnesyl-S-cysteine methyl ester is required for appropriate H-Ras membrane localization and function, including activation of the mitogen-activated protein kinase (MAPK) cascade. We employed a Xenopus laevis oocyte whole-cell model system to examine whether anilinogeranyl diphosphate analogues of similar shape and size, but with a hydrophobicity different from that of the FTase substrate farnesyl diphosphate (FPP), could ablate biological function of H-Ras. Analysis of oocyte maturation kinetics following microinjection of in vitro analogue-modified H-Ras into isoprenoid-depleted oocytes revealed that analogues with a hydrophobicity near that of FPP supported H-Ras biological function, while the analogues p-nitroanilinogeranyl diphosphate (p-NO2-AGPP), p-cyanoanilinogeranyl diphosphate (p-CN-AGPP), and isoxazolaminogeranyl diphosphate (Isox-GPP) with hydrophobicities 2-5 orders of magnitude lower than that of FPP did not. We found that although H-Ras modified with FPP analogues p-NO2-AGPP, p-CN-AGPP, and Isox-GPP was an efficient substrate for C-terminal postprenylation processing by Rce1 and Icmt, co-injection of H-Ras with analogues p-NO2-AGPP, p-CN-AGPP, or Isox-GPP could not activate MAPK. We propose that H-Ras biological function requires a minimum lipophilicity of the prenyl group to allow important interactions downstream of the C-terminal processed H-Ras protein. The hydrophilic FPP analogues p-NO2-AGPP, p-CN-AGPP, and Isox-GPP are H-Ras function inhibitors (RFIs) and serve as lead compounds for a unique class of potential anticancer therapeutics.

Publication types

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

MeSH terms

  • Alkyl and Aryl Transferases / metabolism
  • Animals
  • Catalysis
  • Endopeptidases / metabolism
  • Hydrophobic and Hydrophilic Interactions
  • Metalloendopeptidases
  • Oncogene Protein p21(ras) / antagonists & inhibitors*
  • Oncogene Protein p21(ras) / metabolism
  • Oncogene Protein p21(ras) / physiology*
  • Oocytes / metabolism
  • Polyisoprenyl Phosphates / chemical synthesis
  • Polyisoprenyl Phosphates / pharmacology*
  • Proprotein Convertases
  • Protein Methyltransferases / metabolism
  • Protein Prenylation / drug effects*
  • Saccharomyces cerevisiae Proteins / metabolism
  • Sesquiterpenes / chemical synthesis
  • Sesquiterpenes / pharmacology*
  • Xenopus laevis

Substances

  • Polyisoprenyl Phosphates
  • Saccharomyces cerevisiae Proteins
  • Sesquiterpenes
  • farnesyl pyrophosphate
  • Protein Methyltransferases
  • protein-S-isoprenylcysteine O-methyltransferase
  • Alkyl and Aryl Transferases
  • p21(ras) farnesyl-protein transferase
  • Endopeptidases
  • Proprotein Convertases
  • RCE1 protein, S cerevisiae
  • Metalloendopeptidases
  • Oncogene Protein p21(ras)